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am 45dbfcc7: Improve text rendering and measurement.

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* commit '45dbfcc781a3926d22571b6ccfa3f27ec896f119':
  Improve text rendering and measurement.
This commit is contained in:
Deepanshu Gupta
2014-02-10 19:47:20 +00:00
committed by Android Git Automerger
parent d038afd398 45dbfcc781
commit 1c91b1f7a2
1 changed files with 45 additions and 40 deletions
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85
tools/layoutlib/bridge/src/android/graphics/BidiRenderer.java
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@ -28,7 +28,6 @@ import com.ibm.icu.lang.UScript;
import com.ibm.icu.lang.UScriptRun;
import android.graphics.Paint_Delegate.FontInfo;
import android.graphics.RectF;;
/**
* Render the text by breaking it into various scripts and using the right font for each script.
@ -52,11 +51,12 @@ public class BidiRenderer {
}
}
private Graphics2D graphics;
private Paint_Delegate paint;
private char[] text;
private Graphics2D mGraphics;
private Paint_Delegate mPaint;
private char[] mText;
// Bounds of the text drawn so far.
private RectF bounds;
private RectF mBounds;
private float mBaseline;
/**
* @param graphics May be null.
@ -65,9 +65,9 @@ public class BidiRenderer {
*/
/* package */ BidiRenderer(Graphics2D graphics, Paint_Delegate paint, char[] text) {
assert (paint != null);
this.graphics = graphics;
this.paint = paint;
this.text = text;
mGraphics = graphics;
mPaint = paint;
mText = text;
}
/**
@ -81,25 +81,26 @@ public class BidiRenderer {
* @param advances If not null, then advances for each character to be rendered are returned
* here.
* @param advancesIndex index into advances from where the advances need to be filled.
* @param draw If true and {@link graphics} is not null, draw the rendered text on the graphics
* @param draw If true and {@code graphics} is not null, draw the rendered text on the graphics
* at the given co-ordinates
* @param x The x-coordinate of the left edge of where the text should be drawn on the given
* graphics.
* @param y The y-coordinate at which to draw the text on the given graphics.
* @param y The y-coordinate at which to draw the text on the given mGraphics.
* @return A rectangle specifying the bounds of the text drawn.
*/
/* package */ RectF renderText(int start, int limit, boolean isRtl, float advances[],
/* package */ RectF renderText(int start, int limit, boolean isRtl, float[] advances,
int advancesIndex, boolean draw, float x, float y) {
// We break the text into scripts and then select font based on it and then render each of
// the script runs.
bounds = new RectF(x, y, x, y);
for (ScriptRun run : getScriptRuns(text, start, limit, isRtl, paint.getFonts())) {
mBounds = new RectF(x, y, x, y);
mBaseline = y;
for (ScriptRun run : getScriptRuns(mText, start, limit, isRtl, mPaint.getFonts())) {
int flag = Font.LAYOUT_NO_LIMIT_CONTEXT | Font.LAYOUT_NO_START_CONTEXT;
flag |= isRtl ? Font.LAYOUT_RIGHT_TO_LEFT : Font.LAYOUT_LEFT_TO_RIGHT;
renderScript(run.start, run.limit, run.font, flag, advances, advancesIndex, draw);
advancesIndex += run.limit - run.start;
}
return bounds;
return mBounds;
}
/**
@ -108,20 +109,22 @@ public class BidiRenderer {
* be drawn using the preferred font.
*/
private void renderScript(int start, int limit, FontInfo preferredFont, int flag,
float advances[], int advancesIndex, boolean draw) {
List<FontInfo> fonts = paint.getFonts();
float[] advances, int advancesIndex, boolean draw) {
List<FontInfo> fonts = mPaint.getFonts();
if (fonts == null || preferredFont == null) {
return;
}
while (start < limit) {
boolean foundFont = false;
int canDisplayUpTo = preferredFont.mFont.canDisplayUpTo(text, start, limit);
int canDisplayUpTo = preferredFont.mFont.canDisplayUpTo(mText, start, limit);
if (canDisplayUpTo == -1) {
// We can draw all characters in the text.
render(start, limit, preferredFont, flag, advances, advancesIndex, draw);
return;
} else if (canDisplayUpTo > start) { // can draw something
}
if (canDisplayUpTo > start) {
// We can draw something.
render(start, canDisplayUpTo, preferredFont, flag, advances, advancesIndex, draw);
advancesIndex += canDisplayUpTo - start;
start = canDisplayUpTo;
@ -129,9 +132,9 @@ public class BidiRenderer {
// The current character cannot be drawn with the preferred font. Cycle through all the
// fonts to check which one can draw it.
int charCount = Character.isHighSurrogate(text[start]) ? 2 : 1;
int charCount = Character.isHighSurrogate(mText[start]) ? 2 : 1;
for (FontInfo font : fonts) {
canDisplayUpTo = font.mFont.canDisplayUpTo(text, start, start + charCount);
canDisplayUpTo = font.mFont.canDisplayUpTo(mText, start, start + charCount);
if (canDisplayUpTo == -1) {
render(start, start+charCount, font, flag, advances, advancesIndex, draw);
start += charCount;
@ -154,41 +157,45 @@ public class BidiRenderer {
}
/**
* Render the text with the given font to the right of the bounds passed.
* Renders the text to the right of the bounds with the given font.
* @param font The font to render the text with.
*/
private void render(int start, int limit, FontInfo font, int flag, float advances[],
private void render(int start, int limit, FontInfo font, int flag, float[] advances,
int advancesIndex, boolean draw) {
// Since the metrics don't have anti-aliasing set, we create a new FontRenderContext with
// the anti-aliasing set.
FontRenderContext f = font.mMetrics.getFontRenderContext();
FontRenderContext frc = new FontRenderContext(f.getTransform(), paint.isAntiAliased(),
FontRenderContext frc = new FontRenderContext(f.getTransform(), mPaint.isAntiAliased(),
f.usesFractionalMetrics());
GlyphVector gv = font.mFont.layoutGlyphVector(frc, text, start, limit, flag);
GlyphVector gv = font.mFont.layoutGlyphVector(frc, mText, start, limit, flag);
int ng = gv.getNumGlyphs();
int[] ci = gv.getGlyphCharIndices(0, ng, null);
for (int i = 0; i < ng; i++) {
float adv = gv.getGlyphMetrics(i).getAdvanceX();
if (advances != null) {
if (advances != null) {
for (int i = 0; i < ng; i++) {
int adv_idx = advancesIndex + ci[i];
advances[adv_idx] += adv;
advances[adv_idx] += gv.getGlyphMetrics(i).getAdvanceX();
}
}
if (draw && graphics != null) {
graphics.drawGlyphVector(gv, bounds.right, bounds.bottom);
if (draw && mGraphics != null) {
mGraphics.drawGlyphVector(gv, mBounds.right, mBaseline);
}
Rectangle2D awtBounds = gv.getVisualBounds();
RectF visualBounds = awtRectToAndroidRect(awtBounds, bounds.right, bounds.bottom);
// If the width of the bounds is zero, no text has been drawn yet. Hence, use the
// coordinates from the bounds as an offset only.
if (Math.abs(bounds.right - bounds.left) == 0) {
bounds = visualBounds;
// Update the bounds.
Rectangle2D awtBounds = gv.getLogicalBounds();
RectF bounds = awtRectToAndroidRect(awtBounds, mBounds.right, mBaseline);
// If the width of the bounds is zero, no text had been drawn earlier. Hence, use the
// coordinates from the bounds as an offset.
if (Math.abs(mBounds.right - mBounds.left) == 0) {
mBounds = bounds;
} else {
bounds.union(visualBounds);
mBounds.union(bounds);
}
}
private RectF awtRectToAndroidRect(Rectangle2D awtRec, float offsetX, float offsetY) {
// --- Static helper methods ---
private static RectF awtRectToAndroidRect(Rectangle2D awtRec, float offsetX, float offsetY) {
float left = (float) awtRec.getX();
float top = (float) awtRec.getY();
float right = (float) (left + awtRec.getWidth());
@ -198,8 +205,6 @@ public class BidiRenderer {
return androidRect;
}
// --- Static helper methods ---
/* package */ static List<ScriptRun> getScriptRuns(char[] text, int start, int limit,
boolean isRtl, List<FontInfo> fonts) {
LinkedList<ScriptRun> scriptRuns = new LinkedList<ScriptRun>();