9122b1b168
This is helping spot shadow for 15%-20% increase. With the new algorithm, we are less sensitive to the floating point error. b/16712006 Change-Id: Ie30a6ce01e73d56054a0cf65a84549454339a7fd
1475 lines
58 KiB
C++
1475 lines
58 KiB
C++
/*
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* Copyright (C) 2014 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#define LOG_TAG "OpenGLRenderer"
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// The highest z value can't be higher than (CASTER_Z_CAP_RATIO * light.z)
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#define CASTER_Z_CAP_RATIO 0.95f
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// When there is no umbra, then just fake the umbra using
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// centroid * (1 - FAKE_UMBRA_SIZE_RATIO) + outline * FAKE_UMBRA_SIZE_RATIO
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#define FAKE_UMBRA_SIZE_RATIO 0.05f
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// When the polygon is about 90 vertices, the penumbra + umbra can reach 270 rays.
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// That is consider pretty fine tessllated polygon so far.
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// This is just to prevent using too much some memory when edge slicing is not
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// needed any more.
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#define FINE_TESSELLATED_POLYGON_RAY_NUMBER 270
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/**
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* Extra vertices for the corner for smoother corner.
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* Only for outer loop.
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* Note that we use such extra memory to avoid an extra loop.
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*/
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// For half circle, we could add EXTRA_VERTEX_PER_PI vertices.
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// Set to 1 if we don't want to have any.
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#define SPOT_EXTRA_CORNER_VERTEX_PER_PI 18
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// For the whole polygon, the sum of all the deltas b/t normals is 2 * M_PI,
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// therefore, the maximum number of extra vertices will be twice bigger.
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#define SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER (2 * SPOT_EXTRA_CORNER_VERTEX_PER_PI)
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// For each RADIANS_DIVISOR, we would allocate one more vertex b/t the normals.
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#define SPOT_CORNER_RADIANS_DIVISOR (M_PI / SPOT_EXTRA_CORNER_VERTEX_PER_PI)
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#include <math.h>
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#include <stdlib.h>
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#include <utils/Log.h>
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#include "ShadowTessellator.h"
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#include "SpotShadow.h"
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#include "Vertex.h"
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#include "utils/MathUtils.h"
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// TODO: After we settle down the new algorithm, we can remove the old one and
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// its utility functions.
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// Right now, we still need to keep it for comparison purpose and future expansion.
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namespace android {
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namespace uirenderer {
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static const float EPSILON = 1e-7;
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/**
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* For each polygon's vertex, the light center will project it to the receiver
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* as one of the outline vertex.
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* For each outline vertex, we need to store the position and normal.
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* Normal here is defined against the edge by the current vertex and the next vertex.
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*/
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struct OutlineData {
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Vector2 position;
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Vector2 normal;
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float radius;
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};
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/**
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* For each vertex, we need to keep track of its angle, whether it is penumbra or
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* umbra, and its corresponding vertex index.
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*/
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struct SpotShadow::VertexAngleData {
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// The angle to the vertex from the centroid.
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float mAngle;
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// True is the vertex comes from penumbra, otherwise it comes from umbra.
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bool mIsPenumbra;
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// The index of the vertex described by this data.
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int mVertexIndex;
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void set(float angle, bool isPenumbra, int index) {
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mAngle = angle;
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mIsPenumbra = isPenumbra;
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mVertexIndex = index;
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}
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};
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/**
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* Calculate the angle between and x and a y coordinate.
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* The atan2 range from -PI to PI.
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*/
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static float angle(const Vector2& point, const Vector2& center) {
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return atan2(point.y - center.y, point.x - center.x);
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}
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/**
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* Calculate the intersection of a ray with the line segment defined by two points.
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*
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* Returns a negative value in error conditions.
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* @param rayOrigin The start of the ray
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* @param dx The x vector of the ray
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* @param dy The y vector of the ray
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* @param p1 The first point defining the line segment
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* @param p2 The second point defining the line segment
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* @return The distance along the ray if it intersects with the line segment, negative if otherwise
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*/
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static float rayIntersectPoints(const Vector2& rayOrigin, float dx, float dy,
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const Vector2& p1, const Vector2& p2) {
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// The math below is derived from solving this formula, basically the
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// intersection point should stay on both the ray and the edge of (p1, p2).
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// solve([p1x+t*(p2x-p1x)=dx*t2+px,p1y+t*(p2y-p1y)=dy*t2+py],[t,t2]);
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float divisor = (dx * (p1.y - p2.y) + dy * p2.x - dy * p1.x);
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if (divisor == 0) return -1.0f; // error, invalid divisor
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#if DEBUG_SHADOW
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float interpVal = (dx * (p1.y - rayOrigin.y) + dy * rayOrigin.x - dy * p1.x) / divisor;
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if (interpVal < 0 || interpVal > 1) {
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ALOGW("rayIntersectPoints is hitting outside the segment %f", interpVal);
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}
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#endif
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float distance = (p1.x * (rayOrigin.y - p2.y) + p2.x * (p1.y - rayOrigin.y) +
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rayOrigin.x * (p2.y - p1.y)) / divisor;
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return distance; // may be negative in error cases
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}
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/**
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* Sort points by their X coordinates
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*
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* @param points the points as a Vector2 array.
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* @param pointsLength the number of vertices of the polygon.
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*/
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void SpotShadow::xsort(Vector2* points, int pointsLength) {
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quicksortX(points, 0, pointsLength - 1);
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}
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/**
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* compute the convex hull of a collection of Points
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*
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* @param points the points as a Vector2 array.
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* @param pointsLength the number of vertices of the polygon.
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* @param retPoly pre allocated array of floats to put the vertices
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* @return the number of points in the polygon 0 if no intersection
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*/
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int SpotShadow::hull(Vector2* points, int pointsLength, Vector2* retPoly) {
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xsort(points, pointsLength);
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int n = pointsLength;
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Vector2 lUpper[n];
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lUpper[0] = points[0];
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lUpper[1] = points[1];
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int lUpperSize = 2;
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for (int i = 2; i < n; i++) {
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lUpper[lUpperSize] = points[i];
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lUpperSize++;
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while (lUpperSize > 2 && !ccw(
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lUpper[lUpperSize - 3].x, lUpper[lUpperSize - 3].y,
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lUpper[lUpperSize - 2].x, lUpper[lUpperSize - 2].y,
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lUpper[lUpperSize - 1].x, lUpper[lUpperSize - 1].y)) {
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// Remove the middle point of the three last
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lUpper[lUpperSize - 2].x = lUpper[lUpperSize - 1].x;
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lUpper[lUpperSize - 2].y = lUpper[lUpperSize - 1].y;
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lUpperSize--;
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}
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}
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Vector2 lLower[n];
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lLower[0] = points[n - 1];
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lLower[1] = points[n - 2];
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int lLowerSize = 2;
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for (int i = n - 3; i >= 0; i--) {
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lLower[lLowerSize] = points[i];
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lLowerSize++;
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while (lLowerSize > 2 && !ccw(
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lLower[lLowerSize - 3].x, lLower[lLowerSize - 3].y,
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lLower[lLowerSize - 2].x, lLower[lLowerSize - 2].y,
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lLower[lLowerSize - 1].x, lLower[lLowerSize - 1].y)) {
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// Remove the middle point of the three last
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lLower[lLowerSize - 2] = lLower[lLowerSize - 1];
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lLowerSize--;
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}
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}
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// output points in CW ordering
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const int total = lUpperSize + lLowerSize - 2;
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int outIndex = total - 1;
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for (int i = 0; i < lUpperSize; i++) {
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retPoly[outIndex] = lUpper[i];
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outIndex--;
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}
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for (int i = 1; i < lLowerSize - 1; i++) {
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retPoly[outIndex] = lLower[i];
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outIndex--;
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}
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// TODO: Add test harness which verify that all the points are inside the hull.
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return total;
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}
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/**
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* Test whether the 3 points form a counter clockwise turn.
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*
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* @return true if a right hand turn
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*/
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bool SpotShadow::ccw(float ax, float ay, float bx, float by,
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float cx, float cy) {
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return (bx - ax) * (cy - ay) - (by - ay) * (cx - ax) > EPSILON;
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}
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/**
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* Sort points about a center point
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*
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* @param poly The in and out polyogon as a Vector2 array.
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* @param polyLength The number of vertices of the polygon.
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* @param center the center ctr[0] = x , ctr[1] = y to sort around.
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*/
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void SpotShadow::sort(Vector2* poly, int polyLength, const Vector2& center) {
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quicksortCirc(poly, 0, polyLength - 1, center);
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}
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/**
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* Swap points pointed to by i and j
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*/
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void SpotShadow::swap(Vector2* points, int i, int j) {
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Vector2 temp = points[i];
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points[i] = points[j];
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points[j] = temp;
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}
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/**
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* quick sort implementation about the center.
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*/
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void SpotShadow::quicksortCirc(Vector2* points, int low, int high,
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const Vector2& center) {
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int i = low, j = high;
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int p = low + (high - low) / 2;
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float pivot = angle(points[p], center);
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while (i <= j) {
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while (angle(points[i], center) > pivot) {
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i++;
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}
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while (angle(points[j], center) < pivot) {
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j--;
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}
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if (i <= j) {
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swap(points, i, j);
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i++;
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j--;
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}
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}
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if (low < j) quicksortCirc(points, low, j, center);
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if (i < high) quicksortCirc(points, i, high, center);
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}
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/**
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* Sort points by x axis
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*
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* @param points points to sort
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* @param low start index
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* @param high end index
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*/
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void SpotShadow::quicksortX(Vector2* points, int low, int high) {
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int i = low, j = high;
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int p = low + (high - low) / 2;
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float pivot = points[p].x;
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while (i <= j) {
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while (points[i].x < pivot) {
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i++;
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}
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while (points[j].x > pivot) {
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j--;
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}
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if (i <= j) {
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swap(points, i, j);
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i++;
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j--;
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}
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}
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if (low < j) quicksortX(points, low, j);
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if (i < high) quicksortX(points, i, high);
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}
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/**
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* Test whether a point is inside the polygon.
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*
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* @param testPoint the point to test
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* @param poly the polygon
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* @return true if the testPoint is inside the poly.
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*/
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bool SpotShadow::testPointInsidePolygon(const Vector2 testPoint,
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const Vector2* poly, int len) {
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bool c = false;
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float testx = testPoint.x;
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float testy = testPoint.y;
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for (int i = 0, j = len - 1; i < len; j = i++) {
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float startX = poly[j].x;
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float startY = poly[j].y;
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float endX = poly[i].x;
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float endY = poly[i].y;
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if (((endY > testy) != (startY > testy))
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&& (testx < (startX - endX) * (testy - endY)
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/ (startY - endY) + endX)) {
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c = !c;
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}
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}
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return c;
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}
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/**
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* Make the polygon turn clockwise.
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*
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* @param polygon the polygon as a Vector2 array.
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* @param len the number of points of the polygon
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*/
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void SpotShadow::makeClockwise(Vector2* polygon, int len) {
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if (polygon == 0 || len == 0) {
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return;
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}
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if (!ShadowTessellator::isClockwise(polygon, len)) {
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reverse(polygon, len);
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}
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}
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/**
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* Reverse the polygon
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*
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* @param polygon the polygon as a Vector2 array
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* @param len the number of points of the polygon
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*/
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void SpotShadow::reverse(Vector2* polygon, int len) {
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int n = len / 2;
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for (int i = 0; i < n; i++) {
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Vector2 tmp = polygon[i];
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int k = len - 1 - i;
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polygon[i] = polygon[k];
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polygon[k] = tmp;
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}
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}
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/**
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* Compute a horizontal circular polygon about point (x , y , height) of radius
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* (size)
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*
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* @param points number of the points of the output polygon.
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* @param lightCenter the center of the light.
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* @param size the light size.
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* @param ret result polygon.
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*/
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void SpotShadow::computeLightPolygon(int points, const Vector3& lightCenter,
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float size, Vector3* ret) {
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// TODO: Caching all the sin / cos values and store them in a look up table.
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for (int i = 0; i < points; i++) {
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float angle = 2 * i * M_PI / points;
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ret[i].x = cosf(angle) * size + lightCenter.x;
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ret[i].y = sinf(angle) * size + lightCenter.y;
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ret[i].z = lightCenter.z;
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}
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}
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/**
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* From light center, project one vertex to the z=0 surface and get the outline.
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*
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* @param outline The result which is the outline position.
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* @param lightCenter The center of light.
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* @param polyVertex The input polygon's vertex.
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*
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* @return float The ratio of (polygon.z / light.z - polygon.z)
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*/
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float SpotShadow::projectCasterToOutline(Vector2& outline,
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const Vector3& lightCenter, const Vector3& polyVertex) {
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float lightToPolyZ = lightCenter.z - polyVertex.z;
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float ratioZ = CASTER_Z_CAP_RATIO;
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if (lightToPolyZ != 0) {
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// If any caster's vertex is almost above the light, we just keep it as 95%
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// of the height of the light.
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ratioZ = MathUtils::clamp(polyVertex.z / lightToPolyZ, 0.0f, CASTER_Z_CAP_RATIO);
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}
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outline.x = polyVertex.x - ratioZ * (lightCenter.x - polyVertex.x);
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outline.y = polyVertex.y - ratioZ * (lightCenter.y - polyVertex.y);
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return ratioZ;
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}
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/**
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* Generate the shadow spot light of shape lightPoly and a object poly
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*
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* @param isCasterOpaque whether the caster is opaque
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* @param lightCenter the center of the light
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* @param lightSize the radius of the light
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* @param poly x,y,z vertexes of a convex polygon that occludes the light source
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* @param polyLength number of vertexes of the occluding polygon
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* @param shadowTriangleStrip return an (x,y,alpha) triangle strip representing the shadow. Return
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* empty strip if error.
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*/
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void SpotShadow::createSpotShadow(bool isCasterOpaque, const Vector3& lightCenter,
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float lightSize, const Vector3* poly, int polyLength, const Vector3& polyCentroid,
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VertexBuffer& shadowTriangleStrip) {
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if (CC_UNLIKELY(lightCenter.z <= 0)) {
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ALOGW("Relative Light Z is not positive. No spot shadow!");
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return;
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}
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if (CC_UNLIKELY(polyLength < 3)) {
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#if DEBUG_SHADOW
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ALOGW("Invalid polygon length. No spot shadow!");
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#endif
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return;
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}
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OutlineData outlineData[polyLength];
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Vector2 outlineCentroid;
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// Calculate the projected outline for each polygon's vertices from the light center.
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//
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// O Light
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// /
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// /
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// . Polygon vertex
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// /
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// /
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// O Outline vertices
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//
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// Ratio = (Poly - Outline) / (Light - Poly)
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// Outline.x = Poly.x - Ratio * (Light.x - Poly.x)
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// Outline's radius / Light's radius = Ratio
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// Compute the last outline vertex to make sure we can get the normal and outline
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// in one single loop.
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projectCasterToOutline(outlineData[polyLength - 1].position, lightCenter,
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poly[polyLength - 1]);
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// Take the outline's polygon, calculate the normal for each outline edge.
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int currentNormalIndex = polyLength - 1;
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int nextNormalIndex = 0;
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for (int i = 0; i < polyLength; i++) {
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float ratioZ = projectCasterToOutline(outlineData[i].position,
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lightCenter, poly[i]);
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outlineData[i].radius = ratioZ * lightSize;
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outlineData[currentNormalIndex].normal = ShadowTessellator::calculateNormal(
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outlineData[currentNormalIndex].position,
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outlineData[nextNormalIndex].position);
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currentNormalIndex = (currentNormalIndex + 1) % polyLength;
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nextNormalIndex++;
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}
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projectCasterToOutline(outlineCentroid, lightCenter, polyCentroid);
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int penumbraIndex = 0;
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// Then each polygon's vertex produce at minmal 2 penumbra vertices.
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// Since the size can be dynamic here, we keep track of the size and update
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// the real size at the end.
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int allocatedPenumbraLength = 2 * polyLength + SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER;
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Vector2 penumbra[allocatedPenumbraLength];
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int totalExtraCornerSliceNumber = 0;
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Vector2 umbra[polyLength];
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// When centroid is covered by all circles from outline, then we consider
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// the umbra is invalid, and we will tune down the shadow strength.
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bool hasValidUmbra = true;
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// We need the minimal of RaitoVI to decrease the spot shadow strength accordingly.
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float minRaitoVI = FLT_MAX;
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for (int i = 0; i < polyLength; i++) {
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// Generate all the penumbra's vertices only using the (outline vertex + normal * radius)
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// There is no guarantee that the penumbra is still convex, but for
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// each outline vertex, it will connect to all its corresponding penumbra vertices as
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// triangle fans. And for neighber penumbra vertex, it will be a trapezoid.
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//
|
|
// Penumbra Vertices marked as Pi
|
|
// Outline Vertices marked as Vi
|
|
// (P3)
|
|
// (P2) | ' (P4)
|
|
// (P1)' | | '
|
|
// ' | | '
|
|
// (P0) ------------------------------------------------(P5)
|
|
// | (V0) |(V1)
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// (V3)-----------------------------------(V2)
|
|
int preNormalIndex = (i + polyLength - 1) % polyLength;
|
|
|
|
const Vector2& previousNormal = outlineData[preNormalIndex].normal;
|
|
const Vector2& currentNormal = outlineData[i].normal;
|
|
|
|
// Depending on how roundness we want for each corner, we can subdivide
|
|
// further here and/or introduce some heuristic to decide how much the
|
|
// subdivision should be.
|
|
int currentExtraSliceNumber = ShadowTessellator::getExtraVertexNumber(
|
|
previousNormal, currentNormal, SPOT_CORNER_RADIANS_DIVISOR);
|
|
|
|
int currentCornerSliceNumber = 1 + currentExtraSliceNumber;
|
|
totalExtraCornerSliceNumber += currentExtraSliceNumber;
|
|
#if DEBUG_SHADOW
|
|
ALOGD("currentExtraSliceNumber should be %d", currentExtraSliceNumber);
|
|
ALOGD("currentCornerSliceNumber should be %d", currentCornerSliceNumber);
|
|
ALOGD("totalCornerSliceNumber is %d", totalExtraCornerSliceNumber);
|
|
#endif
|
|
if (CC_UNLIKELY(totalExtraCornerSliceNumber > SPOT_MAX_EXTRA_CORNER_VERTEX_NUMBER)) {
|
|
currentCornerSliceNumber = 1;
|
|
}
|
|
for (int k = 0; k <= currentCornerSliceNumber; k++) {
|
|
Vector2 avgNormal =
|
|
(previousNormal * (currentCornerSliceNumber - k) + currentNormal * k) /
|
|
currentCornerSliceNumber;
|
|
avgNormal.normalize();
|
|
penumbra[penumbraIndex++] = outlineData[i].position +
|
|
avgNormal * outlineData[i].radius;
|
|
}
|
|
|
|
|
|
// Compute the umbra by the intersection from the outline's centroid!
|
|
//
|
|
// (V) ------------------------------------
|
|
// | ' |
|
|
// | ' |
|
|
// | ' (I) |
|
|
// | ' |
|
|
// | ' (C) |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// | |
|
|
// ------------------------------------
|
|
//
|
|
// Connect a line b/t the outline vertex (V) and the centroid (C), it will
|
|
// intersect with the outline vertex's circle at point (I).
|
|
// Now, ratioVI = VI / VC, ratioIC = IC / VC
|
|
// Then the intersetion point can be computed as Ixy = Vxy * ratioIC + Cxy * ratioVI;
|
|
//
|
|
// When all of the outline circles cover the the outline centroid, (like I is
|
|
// on the other side of C), there is no real umbra any more, so we just fake
|
|
// a small area around the centroid as the umbra, and tune down the spot
|
|
// shadow's umbra strength to simulate the effect the whole shadow will
|
|
// become lighter in this case.
|
|
// The ratio can be simulated by using the inverse of maximum of ratioVI for
|
|
// all (V).
|
|
float distOutline = (outlineData[i].position - outlineCentroid).length();
|
|
if (CC_UNLIKELY(distOutline == 0)) {
|
|
// If the outline has 0 area, then there is no spot shadow anyway.
|
|
ALOGW("Outline has 0 area, no spot shadow!");
|
|
return;
|
|
}
|
|
|
|
float ratioVI = outlineData[i].radius / distOutline;
|
|
minRaitoVI = MathUtils::min(minRaitoVI, ratioVI);
|
|
if (ratioVI >= (1 - FAKE_UMBRA_SIZE_RATIO)) {
|
|
ratioVI = (1 - FAKE_UMBRA_SIZE_RATIO);
|
|
}
|
|
// When we know we don't have valid umbra, don't bother to compute the
|
|
// values below. But we can't skip the loop yet since we want to know the
|
|
// maximum ratio.
|
|
float ratioIC = 1 - ratioVI;
|
|
umbra[i] = outlineData[i].position * ratioIC + outlineCentroid * ratioVI;
|
|
}
|
|
|
|
hasValidUmbra = (minRaitoVI <= 1.0);
|
|
float shadowStrengthScale = 1.0;
|
|
if (!hasValidUmbra) {
|
|
#if DEBUG_SHADOW
|
|
ALOGW("The object is too close to the light or too small, no real umbra!");
|
|
#endif
|
|
for (int i = 0; i < polyLength; i++) {
|
|
umbra[i] = outlineData[i].position * FAKE_UMBRA_SIZE_RATIO +
|
|
outlineCentroid * (1 - FAKE_UMBRA_SIZE_RATIO);
|
|
}
|
|
shadowStrengthScale = 1.0 / minRaitoVI;
|
|
}
|
|
|
|
int penumbraLength = penumbraIndex;
|
|
int umbraLength = polyLength;
|
|
|
|
#if DEBUG_SHADOW
|
|
ALOGD("penumbraLength is %d , allocatedPenumbraLength %d", penumbraLength, allocatedPenumbraLength);
|
|
dumpPolygon(poly, polyLength, "input poly");
|
|
dumpPolygon(penumbra, penumbraLength, "penumbra");
|
|
dumpPolygon(umbra, umbraLength, "umbra");
|
|
ALOGD("hasValidUmbra is %d and shadowStrengthScale is %f", hasValidUmbra, shadowStrengthScale);
|
|
#endif
|
|
|
|
// The penumbra and umbra needs to be in convex shape to keep consistency
|
|
// and quality.
|
|
// Since we are still shooting rays to penumbra, it needs to be convex.
|
|
// Umbra can be represented as a fan from the centroid, but visually umbra
|
|
// looks nicer when it is convex.
|
|
Vector2 finalUmbra[umbraLength];
|
|
Vector2 finalPenumbra[penumbraLength];
|
|
int finalUmbraLength = hull(umbra, umbraLength, finalUmbra);
|
|
int finalPenumbraLength = hull(penumbra, penumbraLength, finalPenumbra);
|
|
|
|
generateTriangleStrip(isCasterOpaque, shadowStrengthScale, finalPenumbra,
|
|
finalPenumbraLength, finalUmbra, finalUmbraLength, poly, polyLength,
|
|
shadowTriangleStrip, outlineCentroid);
|
|
|
|
}
|
|
|
|
/**
|
|
* Converts a polygon specified with CW vertices into an array of distance-from-centroid values.
|
|
*
|
|
* Returns false in error conditions
|
|
*
|
|
* @param poly Array of vertices. Note that these *must* be CW.
|
|
* @param polyLength The number of vertices in the polygon.
|
|
* @param polyCentroid The centroid of the polygon, from which rays will be cast
|
|
* @param rayDist The output array for the calculated distances, must be SHADOW_RAY_COUNT in size
|
|
*/
|
|
bool convertPolyToRayDist(const Vector2* poly, int polyLength, const Vector2& polyCentroid,
|
|
float* rayDist) {
|
|
const int rays = SHADOW_RAY_COUNT;
|
|
const float step = M_PI * 2 / rays;
|
|
|
|
const Vector2* lastVertex = &(poly[polyLength - 1]);
|
|
float startAngle = angle(*lastVertex, polyCentroid);
|
|
|
|
// Start with the ray that's closest to and less than startAngle
|
|
int rayIndex = floor((startAngle - EPSILON) / step);
|
|
rayIndex = (rayIndex + rays) % rays; // ensure positive
|
|
|
|
for (int polyIndex = 0; polyIndex < polyLength; polyIndex++) {
|
|
/*
|
|
* For a given pair of vertices on the polygon, poly[i-1] and poly[i], the rays that
|
|
* intersect these will be those that are between the two angles from the centroid that the
|
|
* vertices define.
|
|
*
|
|
* Because the polygon vertices are stored clockwise, the closest ray with an angle
|
|
* *smaller* than that defined by angle(poly[i], centroid) will be the first ray that does
|
|
* not intersect with poly[i-1], poly[i].
|
|
*/
|
|
float currentAngle = angle(poly[polyIndex], polyCentroid);
|
|
|
|
// find first ray that will not intersect the line segment poly[i-1] & poly[i]
|
|
int firstRayIndexOnNextSegment = floor((currentAngle - EPSILON) / step);
|
|
firstRayIndexOnNextSegment = (firstRayIndexOnNextSegment + rays) % rays; // ensure positive
|
|
|
|
// Iterate through all rays that intersect with poly[i-1], poly[i] line segment.
|
|
// This may be 0 rays.
|
|
while (rayIndex != firstRayIndexOnNextSegment) {
|
|
float distanceToIntersect = rayIntersectPoints(polyCentroid,
|
|
cos(rayIndex * step),
|
|
sin(rayIndex * step),
|
|
*lastVertex, poly[polyIndex]);
|
|
if (distanceToIntersect < 0) {
|
|
#if DEBUG_SHADOW
|
|
ALOGW("ERROR: convertPolyToRayDist failed");
|
|
#endif
|
|
return false; // error case, abort
|
|
}
|
|
|
|
rayDist[rayIndex] = distanceToIntersect;
|
|
|
|
rayIndex = (rayIndex - 1 + rays) % rays;
|
|
}
|
|
lastVertex = &poly[polyIndex];
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* This is only for experimental purpose.
|
|
* After intersections are calculated, we could smooth the polygon if needed.
|
|
* So far, we don't think it is more appealing yet.
|
|
*
|
|
* @param level The level of smoothness.
|
|
* @param rays The total number of rays.
|
|
* @param rayDist (In and Out) The distance for each ray.
|
|
*
|
|
*/
|
|
void SpotShadow::smoothPolygon(int level, int rays, float* rayDist) {
|
|
for (int k = 0; k < level; k++) {
|
|
for (int i = 0; i < rays; i++) {
|
|
float p1 = rayDist[(rays - 1 + i) % rays];
|
|
float p2 = rayDist[i];
|
|
float p3 = rayDist[(i + 1) % rays];
|
|
rayDist[i] = (p1 + p2 * 2 + p3) / 4;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Generate a array of the angleData for either umbra or penumbra vertices.
|
|
*
|
|
* This array will be merged and used to guide where to shoot the rays, in clockwise order.
|
|
*
|
|
* @param angleDataList The result array of angle data.
|
|
*
|
|
* @return int The maximum angle's index in the array.
|
|
*/
|
|
int SpotShadow::setupAngleList(VertexAngleData* angleDataList,
|
|
int polyLength, const Vector2* polygon, const Vector2& centroid,
|
|
bool isPenumbra, const char* name) {
|
|
float maxAngle = FLT_MIN;
|
|
int maxAngleIndex = 0;
|
|
for (int i = 0; i < polyLength; i++) {
|
|
float currentAngle = angle(polygon[i], centroid);
|
|
if (currentAngle > maxAngle) {
|
|
maxAngle = currentAngle;
|
|
maxAngleIndex = i;
|
|
}
|
|
angleDataList[i].set(currentAngle, isPenumbra, i);
|
|
#if DEBUG_SHADOW
|
|
ALOGD("%s AngleList i %d %f", name, i, currentAngle);
|
|
#endif
|
|
}
|
|
return maxAngleIndex;
|
|
}
|
|
|
|
/**
|
|
* Make sure the polygons are indeed in clockwise order.
|
|
*
|
|
* Possible reasons to return false: 1. The input polygon is not setup properly. 2. The hull
|
|
* algorithm is not able to generate it properly.
|
|
*
|
|
* Anyway, since the algorithm depends on the clockwise, when these kind of unexpected error
|
|
* situation is found, we need to detect it and early return without corrupting the memory.
|
|
*
|
|
* @return bool True if the angle list is actually from big to small.
|
|
*/
|
|
bool SpotShadow::checkClockwise(int indexOfMaxAngle, int listLength, VertexAngleData* angleList,
|
|
const char* name) {
|
|
int currentIndex = indexOfMaxAngle;
|
|
#if DEBUG_SHADOW
|
|
ALOGD("max index %d", currentIndex);
|
|
#endif
|
|
for (int i = 0; i < listLength - 1; i++) {
|
|
// TODO: Cache the last angle.
|
|
float currentAngle = angleList[currentIndex].mAngle;
|
|
float nextAngle = angleList[(currentIndex + 1) % listLength].mAngle;
|
|
if (currentAngle < nextAngle) {
|
|
#if DEBUG_SHADOW
|
|
ALOGE("%s, is not CW, at index %d", name, currentIndex);
|
|
#endif
|
|
return false;
|
|
}
|
|
currentIndex = (currentIndex + 1) % listLength;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Check the polygon is clockwise.
|
|
*
|
|
* @return bool True is the polygon is clockwise.
|
|
*/
|
|
bool SpotShadow::checkPolyClockwise(int polyAngleLength, int maxPolyAngleIndex,
|
|
const float* polyAngleList) {
|
|
bool isPolyCW = true;
|
|
// Starting from maxPolyAngleIndex , check around to make sure angle decrease.
|
|
for (int i = 0; i < polyAngleLength - 1; i++) {
|
|
float currentAngle = polyAngleList[(i + maxPolyAngleIndex) % polyAngleLength];
|
|
float nextAngle = polyAngleList[(i + maxPolyAngleIndex + 1) % polyAngleLength];
|
|
if (currentAngle < nextAngle) {
|
|
isPolyCW = false;
|
|
}
|
|
}
|
|
return isPolyCW;
|
|
}
|
|
|
|
/**
|
|
* Given the sorted array of all the vertices angle data, calculate for each
|
|
* vertices, the offset value to array element which represent the start edge
|
|
* of the polygon we need to shoot the ray at.
|
|
*
|
|
* TODO: Calculate this for umbra and penumbra in one loop using one single array.
|
|
*
|
|
* @param distances The result of the array distance counter.
|
|
*/
|
|
void SpotShadow::calculateDistanceCounter(bool needsOffsetToUmbra, int angleLength,
|
|
const VertexAngleData* allVerticesAngleData, int* distances) {
|
|
|
|
bool firstVertexIsPenumbra = allVerticesAngleData[0].mIsPenumbra;
|
|
// If we want distance to inner, then we just set to 0 when we see inner.
|
|
bool needsSearch = needsOffsetToUmbra ? firstVertexIsPenumbra : !firstVertexIsPenumbra;
|
|
int distanceCounter = 0;
|
|
if (needsSearch) {
|
|
int foundIndex = -1;
|
|
for (int i = (angleLength - 1); i >= 0; i--) {
|
|
bool currentIsOuter = allVerticesAngleData[i].mIsPenumbra;
|
|
// If we need distance to inner, then we need to find a inner vertex.
|
|
if (currentIsOuter != firstVertexIsPenumbra) {
|
|
foundIndex = i;
|
|
break;
|
|
}
|
|
}
|
|
LOG_ALWAYS_FATAL_IF(foundIndex == -1, "Wrong index found, means either"
|
|
" umbra or penumbra's length is 0");
|
|
distanceCounter = angleLength - foundIndex;
|
|
}
|
|
#if DEBUG_SHADOW
|
|
ALOGD("distances[0] is %d", distanceCounter);
|
|
#endif
|
|
|
|
distances[0] = distanceCounter; // means never see a target poly
|
|
|
|
for (int i = 1; i < angleLength; i++) {
|
|
bool firstVertexIsPenumbra = allVerticesAngleData[i].mIsPenumbra;
|
|
// When we needs for distance for each outer vertex to inner, then we
|
|
// increase the distance when seeing outer vertices. Otherwise, we clear
|
|
// to 0.
|
|
bool needsIncrement = needsOffsetToUmbra ? firstVertexIsPenumbra : !firstVertexIsPenumbra;
|
|
// If counter is not -1, that means we have seen an other polygon's vertex.
|
|
if (needsIncrement && distanceCounter != -1) {
|
|
distanceCounter++;
|
|
} else {
|
|
distanceCounter = 0;
|
|
}
|
|
distances[i] = distanceCounter;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Given umbra and penumbra angle data list, merge them by sorting the angle
|
|
* from the biggest to smallest.
|
|
*
|
|
* @param allVerticesAngleData The result array of merged angle data.
|
|
*/
|
|
void SpotShadow::mergeAngleList(int maxUmbraAngleIndex, int maxPenumbraAngleIndex,
|
|
const VertexAngleData* umbraAngleList, int umbraLength,
|
|
const VertexAngleData* penumbraAngleList, int penumbraLength,
|
|
VertexAngleData* allVerticesAngleData) {
|
|
|
|
int totalRayNumber = umbraLength + penumbraLength;
|
|
int umbraIndex = maxUmbraAngleIndex;
|
|
int penumbraIndex = maxPenumbraAngleIndex;
|
|
|
|
float currentUmbraAngle = umbraAngleList[umbraIndex].mAngle;
|
|
float currentPenumbraAngle = penumbraAngleList[penumbraIndex].mAngle;
|
|
|
|
// TODO: Clean this up using a while loop with 2 iterators.
|
|
for (int i = 0; i < totalRayNumber; i++) {
|
|
if (currentUmbraAngle > currentPenumbraAngle) {
|
|
allVerticesAngleData[i] = umbraAngleList[umbraIndex];
|
|
umbraIndex = (umbraIndex + 1) % umbraLength;
|
|
|
|
// If umbraIndex round back, that means we are running out of
|
|
// umbra vertices to merge, so just copy all the penumbra leftover.
|
|
// Otherwise, we update the currentUmbraAngle.
|
|
if (umbraIndex != maxUmbraAngleIndex) {
|
|
currentUmbraAngle = umbraAngleList[umbraIndex].mAngle;
|
|
} else {
|
|
for (int j = i + 1; j < totalRayNumber; j++) {
|
|
allVerticesAngleData[j] = penumbraAngleList[penumbraIndex];
|
|
penumbraIndex = (penumbraIndex + 1) % penumbraLength;
|
|
}
|
|
break;
|
|
}
|
|
} else {
|
|
allVerticesAngleData[i] = penumbraAngleList[penumbraIndex];
|
|
penumbraIndex = (penumbraIndex + 1) % penumbraLength;
|
|
// If penumbraIndex round back, that means we are running out of
|
|
// penumbra vertices to merge, so just copy all the umbra leftover.
|
|
// Otherwise, we update the currentPenumbraAngle.
|
|
if (penumbraIndex != maxPenumbraAngleIndex) {
|
|
currentPenumbraAngle = penumbraAngleList[penumbraIndex].mAngle;
|
|
} else {
|
|
for (int j = i + 1; j < totalRayNumber; j++) {
|
|
allVerticesAngleData[j] = umbraAngleList[umbraIndex];
|
|
umbraIndex = (umbraIndex + 1) % umbraLength;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#if DEBUG_SHADOW
|
|
/**
|
|
* DEBUG ONLY: Verify all the offset compuation is correctly done by examining
|
|
* each vertex and its neighbor.
|
|
*/
|
|
static void verifyDistanceCounter(const VertexAngleData* allVerticesAngleData,
|
|
const int* distances, int angleLength, const char* name) {
|
|
int currentDistance = distances[0];
|
|
for (int i = 1; i < angleLength; i++) {
|
|
if (distances[i] != INT_MIN) {
|
|
if (!((currentDistance + 1) == distances[i]
|
|
|| distances[i] == 0)) {
|
|
ALOGE("Wrong distance found at i %d name %s", i, name);
|
|
}
|
|
currentDistance = distances[i];
|
|
if (currentDistance != 0) {
|
|
bool currentOuter = allVerticesAngleData[i].mIsPenumbra;
|
|
for (int j = 1; j <= (currentDistance - 1); j++) {
|
|
bool neigborOuter =
|
|
allVerticesAngleData[(i + angleLength - j) % angleLength].mIsPenumbra;
|
|
if (neigborOuter != currentOuter) {
|
|
ALOGE("Wrong distance found at i %d name %s", i, name);
|
|
}
|
|
}
|
|
bool oppositeOuter =
|
|
allVerticesAngleData[(i + angleLength - currentDistance) % angleLength].mIsPenumbra;
|
|
if (oppositeOuter == currentOuter) {
|
|
ALOGE("Wrong distance found at i %d name %s", i, name);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* DEBUG ONLY: Verify all the angle data compuated are is correctly done
|
|
*/
|
|
static void verifyAngleData(int totalRayNumber, const VertexAngleData* allVerticesAngleData,
|
|
const int* distancesToInner, const int* distancesToOuter,
|
|
const VertexAngleData* umbraAngleList, int maxUmbraAngleIndex, int umbraLength,
|
|
const VertexAngleData* penumbraAngleList, int maxPenumbraAngleIndex,
|
|
int penumbraLength) {
|
|
for (int i = 0; i < totalRayNumber; i++) {
|
|
ALOGD("currentAngleList i %d, angle %f, isInner %d, index %d distancesToInner"
|
|
" %d distancesToOuter %d", i, allVerticesAngleData[i].mAngle,
|
|
!allVerticesAngleData[i].mIsPenumbra,
|
|
allVerticesAngleData[i].mVertexIndex, distancesToInner[i], distancesToOuter[i]);
|
|
}
|
|
|
|
verifyDistanceCounter(allVerticesAngleData, distancesToInner, totalRayNumber, "distancesToInner");
|
|
verifyDistanceCounter(allVerticesAngleData, distancesToOuter, totalRayNumber, "distancesToOuter");
|
|
|
|
for (int i = 0; i < totalRayNumber; i++) {
|
|
if ((distancesToInner[i] * distancesToOuter[i]) != 0) {
|
|
ALOGE("distancesToInner wrong at index %d distancesToInner[i] %d,"
|
|
" distancesToOuter[i] %d", i, distancesToInner[i], distancesToOuter[i]);
|
|
}
|
|
}
|
|
int currentUmbraVertexIndex =
|
|
umbraAngleList[maxUmbraAngleIndex].mVertexIndex;
|
|
int currentPenumbraVertexIndex =
|
|
penumbraAngleList[maxPenumbraAngleIndex].mVertexIndex;
|
|
for (int i = 0; i < totalRayNumber; i++) {
|
|
if (allVerticesAngleData[i].mIsPenumbra == true) {
|
|
if (allVerticesAngleData[i].mVertexIndex != currentPenumbraVertexIndex) {
|
|
ALOGW("wrong penumbra indexing i %d allVerticesAngleData[i].mVertexIndex %d "
|
|
"currentpenumbraVertexIndex %d", i,
|
|
allVerticesAngleData[i].mVertexIndex, currentPenumbraVertexIndex);
|
|
}
|
|
currentPenumbraVertexIndex = (currentPenumbraVertexIndex + 1) % penumbraLength;
|
|
} else {
|
|
if (allVerticesAngleData[i].mVertexIndex != currentUmbraVertexIndex) {
|
|
ALOGW("wrong umbra indexing i %d allVerticesAngleData[i].mVertexIndex %d "
|
|
"currentUmbraVertexIndex %d", i,
|
|
allVerticesAngleData[i].mVertexIndex, currentUmbraVertexIndex);
|
|
}
|
|
currentUmbraVertexIndex = (currentUmbraVertexIndex + 1) % umbraLength;
|
|
}
|
|
}
|
|
for (int i = 0; i < totalRayNumber - 1; i++) {
|
|
float currentAngle = allVerticesAngleData[i].mAngle;
|
|
float nextAngle = allVerticesAngleData[(i + 1) % totalRayNumber].mAngle;
|
|
if (currentAngle < nextAngle) {
|
|
ALOGE("Unexpected angle values!, currentAngle nextAngle %f %f", currentAngle, nextAngle);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* In order to compute the occluded umbra, we need to setup the angle data list
|
|
* for the polygon data. Since we only store one poly vertex per polygon vertex,
|
|
* this array only needs to be a float array which are the angles for each vertex.
|
|
*
|
|
* @param polyAngleList The result list
|
|
*
|
|
* @return int The index for the maximum angle in this array.
|
|
*/
|
|
int SpotShadow::setupPolyAngleList(float* polyAngleList, int polyAngleLength,
|
|
const Vector2* poly2d, const Vector2& centroid) {
|
|
int maxPolyAngleIndex = -1;
|
|
float maxPolyAngle = -FLT_MAX;
|
|
for (int i = 0; i < polyAngleLength; i++) {
|
|
polyAngleList[i] = angle(poly2d[i], centroid);
|
|
if (polyAngleList[i] > maxPolyAngle) {
|
|
maxPolyAngle = polyAngleList[i];
|
|
maxPolyAngleIndex = i;
|
|
}
|
|
}
|
|
return maxPolyAngleIndex;
|
|
}
|
|
|
|
/**
|
|
* For umbra and penumbra, given the offset info and the current ray number,
|
|
* find the right edge index (the (starting vertex) for the ray to shoot at.
|
|
*
|
|
* @return int The index of the starting vertex of the edge.
|
|
*/
|
|
inline int SpotShadow::getEdgeStartIndex(const int* offsets, int rayIndex, int totalRayNumber,
|
|
const VertexAngleData* allVerticesAngleData) {
|
|
int tempOffset = offsets[rayIndex];
|
|
int targetRayIndex = (rayIndex - tempOffset + totalRayNumber) % totalRayNumber;
|
|
return allVerticesAngleData[targetRayIndex].mVertexIndex;
|
|
}
|
|
|
|
/**
|
|
* For the occluded umbra, given the array of angles, find the index of the
|
|
* starting vertex of the edge, for the ray to shoo at.
|
|
*
|
|
* TODO: Save the last result to shorten the search distance.
|
|
*
|
|
* @return int The index of the starting vertex of the edge.
|
|
*/
|
|
inline int SpotShadow::getPolyEdgeStartIndex(int maxPolyAngleIndex, int polyLength,
|
|
const float* polyAngleList, float rayAngle) {
|
|
int minPolyAngleIndex = (maxPolyAngleIndex + polyLength - 1) % polyLength;
|
|
int resultIndex = -1;
|
|
if (rayAngle > polyAngleList[maxPolyAngleIndex]
|
|
|| rayAngle <= polyAngleList[minPolyAngleIndex]) {
|
|
resultIndex = minPolyAngleIndex;
|
|
} else {
|
|
for (int i = 0; i < polyLength - 1; i++) {
|
|
int currentIndex = (maxPolyAngleIndex + i) % polyLength;
|
|
int nextIndex = (maxPolyAngleIndex + i + 1) % polyLength;
|
|
if (rayAngle <= polyAngleList[currentIndex]
|
|
&& rayAngle > polyAngleList[nextIndex]) {
|
|
resultIndex = currentIndex;
|
|
}
|
|
}
|
|
}
|
|
if (CC_UNLIKELY(resultIndex == -1)) {
|
|
// TODO: Add more error handling here.
|
|
ALOGE("Wrong index found, means no edge can't be found for rayAngle %f", rayAngle);
|
|
}
|
|
return resultIndex;
|
|
}
|
|
|
|
/**
|
|
* Convert the incoming polygons into arrays of vertices, for each ray.
|
|
* Ray only shoots when there is one vertex either on penumbra on umbra.
|
|
*
|
|
* Finally, it will generate vertices per ray for umbra, penumbra and optionally
|
|
* occludedUmbra.
|
|
*
|
|
* Return true (success) when all vertices are generated
|
|
*/
|
|
int SpotShadow::convertPolysToVerticesPerRay(
|
|
bool hasOccludedUmbraArea, const Vector2* poly2d, int polyLength,
|
|
const Vector2* umbra, int umbraLength, const Vector2* penumbra,
|
|
int penumbraLength, const Vector2& centroid,
|
|
Vector2* umbraVerticesPerRay, Vector2* penumbraVerticesPerRay,
|
|
Vector2* occludedUmbraVerticesPerRay) {
|
|
int totalRayNumber = umbraLength + penumbraLength;
|
|
|
|
// For incoming umbra / penumbra polygons, we will build an intermediate data
|
|
// structure to help us sort all the vertices according to the vertices.
|
|
// Using this data structure, we can tell where (the angle) to shoot the ray,
|
|
// whether we shoot at penumbra edge or umbra edge, and which edge to shoot at.
|
|
//
|
|
// We first parse each vertices and generate a table of VertexAngleData.
|
|
// Based on that, we create 2 arrays telling us which edge to shoot at.
|
|
VertexAngleData allVerticesAngleData[totalRayNumber];
|
|
VertexAngleData umbraAngleList[umbraLength];
|
|
VertexAngleData penumbraAngleList[penumbraLength];
|
|
|
|
int polyAngleLength = hasOccludedUmbraArea ? polyLength : 0;
|
|
float polyAngleList[polyAngleLength];
|
|
|
|
const int maxUmbraAngleIndex =
|
|
setupAngleList(umbraAngleList, umbraLength, umbra, centroid, false, "umbra");
|
|
const int maxPenumbraAngleIndex =
|
|
setupAngleList(penumbraAngleList, penumbraLength, penumbra, centroid, true, "penumbra");
|
|
const int maxPolyAngleIndex = setupPolyAngleList(polyAngleList, polyAngleLength, poly2d, centroid);
|
|
|
|
// Check all the polygons here are CW.
|
|
bool isPolyCW = checkPolyClockwise(polyAngleLength, maxPolyAngleIndex, polyAngleList);
|
|
bool isUmbraCW = checkClockwise(maxUmbraAngleIndex, umbraLength,
|
|
umbraAngleList, "umbra");
|
|
bool isPenumbraCW = checkClockwise(maxPenumbraAngleIndex, penumbraLength,
|
|
penumbraAngleList, "penumbra");
|
|
|
|
if (!isUmbraCW || !isPenumbraCW || !isPolyCW) {
|
|
#if DEBUG_SHADOW
|
|
ALOGE("One polygon is not CW isUmbraCW %d isPenumbraCW %d isPolyCW %d",
|
|
isUmbraCW, isPenumbraCW, isPolyCW);
|
|
#endif
|
|
return false;
|
|
}
|
|
|
|
mergeAngleList(maxUmbraAngleIndex, maxPenumbraAngleIndex,
|
|
umbraAngleList, umbraLength, penumbraAngleList, penumbraLength,
|
|
allVerticesAngleData);
|
|
|
|
// Calculate the offset to the left most Inner vertex for each outerVertex.
|
|
// Then the offset to the left most Outer vertex for each innerVertex.
|
|
int offsetToInner[totalRayNumber];
|
|
int offsetToOuter[totalRayNumber];
|
|
calculateDistanceCounter(true, totalRayNumber, allVerticesAngleData, offsetToInner);
|
|
calculateDistanceCounter(false, totalRayNumber, allVerticesAngleData, offsetToOuter);
|
|
|
|
// Generate both umbraVerticesPerRay and penumbraVerticesPerRay
|
|
for (int i = 0; i < totalRayNumber; i++) {
|
|
float rayAngle = allVerticesAngleData[i].mAngle;
|
|
bool isUmbraVertex = !allVerticesAngleData[i].mIsPenumbra;
|
|
|
|
float dx = cosf(rayAngle);
|
|
float dy = sinf(rayAngle);
|
|
float distanceToIntersectUmbra = -1;
|
|
|
|
if (isUmbraVertex) {
|
|
// We can just copy umbra easily, and calculate the distance for the
|
|
// occluded umbra computation.
|
|
int startUmbraIndex = allVerticesAngleData[i].mVertexIndex;
|
|
umbraVerticesPerRay[i] = umbra[startUmbraIndex];
|
|
if (hasOccludedUmbraArea) {
|
|
distanceToIntersectUmbra = (umbraVerticesPerRay[i] - centroid).length();
|
|
}
|
|
|
|
//shoot ray to penumbra only
|
|
int startPenumbraIndex = getEdgeStartIndex(offsetToOuter, i, totalRayNumber,
|
|
allVerticesAngleData);
|
|
float distanceToIntersectPenumbra = rayIntersectPoints(centroid, dx, dy,
|
|
penumbra[startPenumbraIndex],
|
|
penumbra[(startPenumbraIndex + 1) % penumbraLength]);
|
|
if (distanceToIntersectPenumbra < 0) {
|
|
#if DEBUG_SHADOW
|
|
ALOGW("convertPolyToRayDist for penumbra failed rayAngle %f dx %f dy %f",
|
|
rayAngle, dx, dy);
|
|
#endif
|
|
distanceToIntersectPenumbra = 0;
|
|
}
|
|
penumbraVerticesPerRay[i].x = centroid.x + dx * distanceToIntersectPenumbra;
|
|
penumbraVerticesPerRay[i].y = centroid.y + dy * distanceToIntersectPenumbra;
|
|
} else {
|
|
// We can just copy the penumbra
|
|
int startPenumbraIndex = allVerticesAngleData[i].mVertexIndex;
|
|
penumbraVerticesPerRay[i] = penumbra[startPenumbraIndex];
|
|
|
|
// And shoot ray to umbra only
|
|
int startUmbraIndex = getEdgeStartIndex(offsetToInner, i, totalRayNumber,
|
|
allVerticesAngleData);
|
|
|
|
distanceToIntersectUmbra = rayIntersectPoints(centroid, dx, dy,
|
|
umbra[startUmbraIndex], umbra[(startUmbraIndex + 1) % umbraLength]);
|
|
if (distanceToIntersectUmbra < 0) {
|
|
#if DEBUG_SHADOW
|
|
ALOGW("convertPolyToRayDist for umbra failed rayAngle %f dx %f dy %f",
|
|
rayAngle, dx, dy);
|
|
#endif
|
|
distanceToIntersectUmbra = 0;
|
|
}
|
|
umbraVerticesPerRay[i].x = centroid.x + dx * distanceToIntersectUmbra;
|
|
umbraVerticesPerRay[i].y = centroid.y + dy * distanceToIntersectUmbra;
|
|
}
|
|
|
|
if (hasOccludedUmbraArea) {
|
|
// Shoot the same ray to the poly2d, and get the distance.
|
|
int startPolyIndex = getPolyEdgeStartIndex(maxPolyAngleIndex, polyLength,
|
|
polyAngleList, rayAngle);
|
|
|
|
float distanceToIntersectPoly = rayIntersectPoints(centroid, dx, dy,
|
|
poly2d[startPolyIndex], poly2d[(startPolyIndex + 1) % polyLength]);
|
|
if (distanceToIntersectPoly < 0) {
|
|
distanceToIntersectPoly = 0;
|
|
}
|
|
distanceToIntersectPoly = MathUtils::min(distanceToIntersectUmbra, distanceToIntersectPoly);
|
|
occludedUmbraVerticesPerRay[i].x = centroid.x + dx * distanceToIntersectPoly;
|
|
occludedUmbraVerticesPerRay[i].y = centroid.y + dy * distanceToIntersectPoly;
|
|
}
|
|
}
|
|
|
|
#if DEBUG_SHADOW
|
|
verifyAngleData(totalRayNumber, allVerticesAngleData, offsetToInner,
|
|
offsetToOuter, umbraAngleList, maxUmbraAngleIndex, umbraLength,
|
|
penumbraAngleList, maxPenumbraAngleIndex, penumbraLength);
|
|
#endif
|
|
return true; // success
|
|
|
|
}
|
|
|
|
/**
|
|
* Generate a triangle strip given two convex polygon
|
|
**/
|
|
void SpotShadow::generateTriangleStrip(bool isCasterOpaque, float shadowStrengthScale,
|
|
Vector2* penumbra, int penumbraLength, Vector2* umbra, int umbraLength,
|
|
const Vector3* poly, int polyLength, VertexBuffer& shadowTriangleStrip,
|
|
const Vector2& centroid) {
|
|
|
|
bool hasOccludedUmbraArea = false;
|
|
Vector2 poly2d[polyLength];
|
|
|
|
if (isCasterOpaque) {
|
|
for (int i = 0; i < polyLength; i++) {
|
|
poly2d[i].x = poly[i].x;
|
|
poly2d[i].y = poly[i].y;
|
|
}
|
|
// Make sure the centroid is inside the umbra, otherwise, fall back to the
|
|
// approach as if there is no occluded umbra area.
|
|
if (testPointInsidePolygon(centroid, poly2d, polyLength)) {
|
|
hasOccludedUmbraArea = true;
|
|
}
|
|
}
|
|
|
|
int totalRayNum = umbraLength + penumbraLength;
|
|
Vector2 umbraVertices[totalRayNum];
|
|
Vector2 penumbraVertices[totalRayNum];
|
|
Vector2 occludedUmbraVertices[totalRayNum];
|
|
bool convertSuccess = convertPolysToVerticesPerRay(hasOccludedUmbraArea, poly2d,
|
|
polyLength, umbra, umbraLength, penumbra, penumbraLength,
|
|
centroid, umbraVertices, penumbraVertices, occludedUmbraVertices);
|
|
if (!convertSuccess) {
|
|
return;
|
|
}
|
|
|
|
// Minimal value is 1, for each vertex show up once.
|
|
// The bigger this value is , the smoother the look is, but more memory
|
|
// is consumed.
|
|
// When the ray number is high, that means the polygon has been fine
|
|
// tessellated, we don't need this extra slice, just keep it as 1.
|
|
int sliceNumberPerEdge = (totalRayNum > FINE_TESSELLATED_POLYGON_RAY_NUMBER) ? 1 : 2;
|
|
|
|
// For each polygon, we at most add (totalRayNum * sliceNumberPerEdge) vertices.
|
|
int slicedVertexCountPerPolygon = totalRayNum * sliceNumberPerEdge;
|
|
int totalVertexCount = slicedVertexCountPerPolygon * 2 + totalRayNum;
|
|
int totalIndexCount = 2 * (slicedVertexCountPerPolygon * 2 + 2);
|
|
AlphaVertex* shadowVertices =
|
|
shadowTriangleStrip.alloc<AlphaVertex>(totalVertexCount);
|
|
uint16_t* indexBuffer =
|
|
shadowTriangleStrip.allocIndices<uint16_t>(totalIndexCount);
|
|
|
|
int indexBufferIndex = 0;
|
|
int vertexBufferIndex = 0;
|
|
|
|
uint16_t slicedUmbraVertexIndex[totalRayNum * sliceNumberPerEdge];
|
|
// Should be something like 0 0 0 1 1 1 2 3 3 3...
|
|
int rayNumberPerSlicedUmbra[totalRayNum * sliceNumberPerEdge];
|
|
int realUmbraVertexCount = 0;
|
|
for (int i = 0; i < totalRayNum; i++) {
|
|
Vector2 currentPenumbra = penumbraVertices[i];
|
|
Vector2 currentUmbra = umbraVertices[i];
|
|
|
|
Vector2 nextPenumbra = penumbraVertices[(i + 1) % totalRayNum];
|
|
Vector2 nextUmbra = umbraVertices[(i + 1) % totalRayNum];
|
|
// NextUmbra/Penumbra will be done in the next loop!!
|
|
for (int weight = 0; weight < sliceNumberPerEdge; weight++) {
|
|
const Vector2& slicedPenumbra = (currentPenumbra * (sliceNumberPerEdge - weight)
|
|
+ nextPenumbra * weight) / sliceNumberPerEdge;
|
|
|
|
const Vector2& slicedUmbra = (currentUmbra * (sliceNumberPerEdge - weight)
|
|
+ nextUmbra * weight) / sliceNumberPerEdge;
|
|
|
|
// In the vertex buffer, we fill the Penumbra first, then umbra.
|
|
indexBuffer[indexBufferIndex++] = vertexBufferIndex;
|
|
AlphaVertex::set(&shadowVertices[vertexBufferIndex++], slicedPenumbra.x,
|
|
slicedPenumbra.y, 0.0f);
|
|
|
|
// When we add umbra vertex, we need to remember its current ray number.
|
|
// And its own vertexBufferIndex. This is for occluded umbra usage.
|
|
indexBuffer[indexBufferIndex++] = vertexBufferIndex;
|
|
rayNumberPerSlicedUmbra[realUmbraVertexCount] = i;
|
|
slicedUmbraVertexIndex[realUmbraVertexCount] = vertexBufferIndex;
|
|
realUmbraVertexCount++;
|
|
AlphaVertex::set(&shadowVertices[vertexBufferIndex++], slicedUmbra.x,
|
|
slicedUmbra.y, M_PI);
|
|
}
|
|
}
|
|
|
|
indexBuffer[indexBufferIndex++] = 0;
|
|
//RealUmbraVertexIndex[0] must be 1, so we connect back well at the
|
|
//beginning of occluded area.
|
|
indexBuffer[indexBufferIndex++] = 1;
|
|
|
|
float occludedUmbraAlpha = M_PI;
|
|
if (hasOccludedUmbraArea) {
|
|
// Now the occludedUmbra area;
|
|
int currentRayNumber = -1;
|
|
int firstOccludedUmbraIndex = -1;
|
|
for (int i = 0; i < realUmbraVertexCount; i++) {
|
|
indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[i];
|
|
|
|
// If the occludedUmbra vertex has not been added yet, then add it.
|
|
// Otherwise, just use the previously added occludedUmbra vertices.
|
|
if (rayNumberPerSlicedUmbra[i] != currentRayNumber) {
|
|
currentRayNumber++;
|
|
indexBuffer[indexBufferIndex++] = vertexBufferIndex;
|
|
// We need to remember the begining of the occludedUmbra vertices
|
|
// to close this loop.
|
|
if (currentRayNumber == 0) {
|
|
firstOccludedUmbraIndex = vertexBufferIndex;
|
|
}
|
|
AlphaVertex::set(&shadowVertices[vertexBufferIndex++],
|
|
occludedUmbraVertices[currentRayNumber].x,
|
|
occludedUmbraVertices[currentRayNumber].y,
|
|
occludedUmbraAlpha);
|
|
} else {
|
|
indexBuffer[indexBufferIndex++] = (vertexBufferIndex - 1);
|
|
}
|
|
}
|
|
// Close the loop here!
|
|
indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[0];
|
|
indexBuffer[indexBufferIndex++] = firstOccludedUmbraIndex;
|
|
} else {
|
|
int lastCentroidIndex = vertexBufferIndex;
|
|
AlphaVertex::set(&shadowVertices[vertexBufferIndex++], centroid.x,
|
|
centroid.y, occludedUmbraAlpha);
|
|
for (int i = 0; i < realUmbraVertexCount; i++) {
|
|
indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[i];
|
|
indexBuffer[indexBufferIndex++] = lastCentroidIndex;
|
|
}
|
|
// Close the loop here!
|
|
indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[0];
|
|
indexBuffer[indexBufferIndex++] = lastCentroidIndex;
|
|
}
|
|
|
|
#if DEBUG_SHADOW
|
|
ALOGD("allocated IB %d allocated VB is %d", totalIndexCount, totalVertexCount);
|
|
ALOGD("IB index %d VB index is %d", indexBufferIndex, vertexBufferIndex);
|
|
for (int i = 0; i < vertexBufferIndex; i++) {
|
|
ALOGD("vertexBuffer i %d, (%f, %f %f)", i, shadowVertices[i].x, shadowVertices[i].y,
|
|
shadowVertices[i].alpha);
|
|
}
|
|
for (int i = 0; i < indexBufferIndex; i++) {
|
|
ALOGD("indexBuffer i %d, indexBuffer[i] %d", i, indexBuffer[i]);
|
|
}
|
|
#endif
|
|
|
|
// At the end, update the real index and vertex buffer size.
|
|
shadowTriangleStrip.updateVertexCount(vertexBufferIndex);
|
|
shadowTriangleStrip.updateIndexCount(indexBufferIndex);
|
|
ShadowTessellator::checkOverflow(vertexBufferIndex, totalVertexCount, "Spot Vertex Buffer");
|
|
ShadowTessellator::checkOverflow(indexBufferIndex, totalIndexCount, "Spot Index Buffer");
|
|
|
|
shadowTriangleStrip.setMode(VertexBuffer::kIndices);
|
|
shadowTriangleStrip.computeBounds<AlphaVertex>();
|
|
}
|
|
|
|
#if DEBUG_SHADOW
|
|
|
|
#define TEST_POINT_NUMBER 128
|
|
/**
|
|
* Calculate the bounds for generating random test points.
|
|
*/
|
|
void SpotShadow::updateBound(const Vector2 inVector, Vector2& lowerBound,
|
|
Vector2& upperBound) {
|
|
if (inVector.x < lowerBound.x) {
|
|
lowerBound.x = inVector.x;
|
|
}
|
|
|
|
if (inVector.y < lowerBound.y) {
|
|
lowerBound.y = inVector.y;
|
|
}
|
|
|
|
if (inVector.x > upperBound.x) {
|
|
upperBound.x = inVector.x;
|
|
}
|
|
|
|
if (inVector.y > upperBound.y) {
|
|
upperBound.y = inVector.y;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* For debug purpose, when things go wrong, dump the whole polygon data.
|
|
*/
|
|
void SpotShadow::dumpPolygon(const Vector2* poly, int polyLength, const char* polyName) {
|
|
for (int i = 0; i < polyLength; i++) {
|
|
ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y);
|
|
}
|
|
}
|
|
|
|
/**
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|
* For debug purpose, when things go wrong, dump the whole polygon data.
|
|
*/
|
|
void SpotShadow::dumpPolygon(const Vector3* poly, int polyLength, const char* polyName) {
|
|
for (int i = 0; i < polyLength; i++) {
|
|
ALOGD("polygon %s i %d x %f y %f", polyName, i, poly[i].x, poly[i].y);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Test whether the polygon is convex.
|
|
*/
|
|
bool SpotShadow::testConvex(const Vector2* polygon, int polygonLength,
|
|
const char* name) {
|
|
bool isConvex = true;
|
|
for (int i = 0; i < polygonLength; i++) {
|
|
Vector2 start = polygon[i];
|
|
Vector2 middle = polygon[(i + 1) % polygonLength];
|
|
Vector2 end = polygon[(i + 2) % polygonLength];
|
|
|
|
float delta = (float(middle.x) - start.x) * (float(end.y) - start.y) -
|
|
(float(middle.y) - start.y) * (float(end.x) - start.x);
|
|
bool isCCWOrCoLinear = (delta >= EPSILON);
|
|
|
|
if (isCCWOrCoLinear) {
|
|
ALOGW("(Error Type 2): polygon (%s) is not a convex b/c start (x %f, y %f),"
|
|
"middle (x %f, y %f) and end (x %f, y %f) , delta is %f !!!",
|
|
name, start.x, start.y, middle.x, middle.y, end.x, end.y, delta);
|
|
isConvex = false;
|
|
break;
|
|
}
|
|
}
|
|
return isConvex;
|
|
}
|
|
|
|
/**
|
|
* Test whether or not the polygon (intersection) is within the 2 input polygons.
|
|
* Using Marte Carlo method, we generate a random point, and if it is inside the
|
|
* intersection, then it must be inside both source polygons.
|
|
*/
|
|
void SpotShadow::testIntersection(const Vector2* poly1, int poly1Length,
|
|
const Vector2* poly2, int poly2Length,
|
|
const Vector2* intersection, int intersectionLength) {
|
|
// Find the min and max of x and y.
|
|
Vector2 lowerBound = {FLT_MAX, FLT_MAX};
|
|
Vector2 upperBound = {-FLT_MAX, -FLT_MAX};
|
|
for (int i = 0; i < poly1Length; i++) {
|
|
updateBound(poly1[i], lowerBound, upperBound);
|
|
}
|
|
for (int i = 0; i < poly2Length; i++) {
|
|
updateBound(poly2[i], lowerBound, upperBound);
|
|
}
|
|
|
|
bool dumpPoly = false;
|
|
for (int k = 0; k < TEST_POINT_NUMBER; k++) {
|
|
// Generate a random point between minX, minY and maxX, maxY.
|
|
float randomX = rand() / float(RAND_MAX);
|
|
float randomY = rand() / float(RAND_MAX);
|
|
|
|
Vector2 testPoint;
|
|
testPoint.x = lowerBound.x + randomX * (upperBound.x - lowerBound.x);
|
|
testPoint.y = lowerBound.y + randomY * (upperBound.y - lowerBound.y);
|
|
|
|
// If the random point is in both poly 1 and 2, then it must be intersection.
|
|
if (testPointInsidePolygon(testPoint, intersection, intersectionLength)) {
|
|
if (!testPointInsidePolygon(testPoint, poly1, poly1Length)) {
|
|
dumpPoly = true;
|
|
ALOGW("(Error Type 1): one point (%f, %f) in the intersection is"
|
|
" not in the poly1",
|
|
testPoint.x, testPoint.y);
|
|
}
|
|
|
|
if (!testPointInsidePolygon(testPoint, poly2, poly2Length)) {
|
|
dumpPoly = true;
|
|
ALOGW("(Error Type 1): one point (%f, %f) in the intersection is"
|
|
" not in the poly2",
|
|
testPoint.x, testPoint.y);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (dumpPoly) {
|
|
dumpPolygon(intersection, intersectionLength, "intersection");
|
|
for (int i = 1; i < intersectionLength; i++) {
|
|
Vector2 delta = intersection[i] - intersection[i - 1];
|
|
ALOGD("Intersetion i, %d Vs i-1 is delta %f", i, delta.lengthSquared());
|
|
}
|
|
|
|
dumpPolygon(poly1, poly1Length, "poly 1");
|
|
dumpPolygon(poly2, poly2Length, "poly 2");
|
|
}
|
|
}
|
|
#endif
|
|
|
|
}; // namespace uirenderer
|
|
}; // namespace android
|