ztenghui 55bfb4e728 Calculate and show Ambient shadow.
Basically we compute the shadow as a strip of triangles, whose alpha value
is the strength of the shadow.
We use the normal to extend the geometry.
And we use static function and try to avoid new/malloc in the computation.

Change-Id: I382286f1cad351bd5ff983f76f446c075819dcaf
2013-12-13 17:25:47 -08:00

103 lines
3.1 KiB
C++

/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_HWUI_VERTEX_BUFFER_H
#define ANDROID_HWUI_VERTEX_BUFFER_H
namespace android {
namespace uirenderer {
class VertexBuffer {
public:
VertexBuffer():
mBuffer(0),
mVertexCount(0),
mCleanupMethod(NULL)
{}
~VertexBuffer() {
if (mCleanupMethod) mCleanupMethod(mBuffer);
}
/**
This should be the only method used by the Tessellator. Subsequent calls to
alloc will allocate space within the first allocation (useful if you want to
eventually allocate multiple regions within a single VertexBuffer, such as
with PathTessellator::tesselateLines())
*/
template <class TYPE>
TYPE* alloc(int vertexCount) {
if (mVertexCount) {
TYPE* reallocBuffer = (TYPE*)mReallocBuffer;
// already have allocated the buffer, re-allocate space within
if (mReallocBuffer != mBuffer) {
// not first re-allocation, leave space for degenerate triangles to separate strips
reallocBuffer += 2;
}
mReallocBuffer = reallocBuffer + vertexCount;
return reallocBuffer;
}
mVertexCount = vertexCount;
mReallocBuffer = mBuffer = (void*)new TYPE[vertexCount];
mCleanupMethod = &(cleanup<TYPE>);
return (TYPE*)mBuffer;
}
template <class TYPE>
void copyInto(const VertexBuffer& srcBuffer, float xOffset, float yOffset) {
int verticesToCopy = srcBuffer.getVertexCount();
TYPE* dst = alloc<TYPE>(verticesToCopy);
TYPE* src = (TYPE*)srcBuffer.getBuffer();
for (int i = 0; i < verticesToCopy; i++) {
TYPE::copyWithOffset(&dst[i], src[i], xOffset, yOffset);
}
}
const void* getBuffer() const { return mBuffer; }
unsigned int getVertexCount() const { return mVertexCount; }
template <class TYPE>
void createDegenerateSeparators(int allocSize) {
TYPE* end = (TYPE*)mBuffer + mVertexCount;
for (TYPE* degen = (TYPE*)mBuffer + allocSize; degen < end; degen += 2 + allocSize) {
memcpy(degen, degen - 1, sizeof(TYPE));
memcpy(degen + 1, degen + 2, sizeof(TYPE));
}
}
private:
template <class TYPE>
static void cleanup(void* buffer) {
delete[] (TYPE*)buffer;
}
void* mBuffer;
unsigned int mVertexCount;
void* mReallocBuffer; // used for multi-allocation
void (*mCleanupMethod)(void*);
};
}; // namespace uirenderer
}; // namespace android
#endif // ANDROID_HWUI_VERTEX_BUFFER_H