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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 com.ibm.icu.lang.UScriptRun;
import android.graphics.Paint_Delegate.FontInfo; 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. * 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 Graphics2D mGraphics;
private Paint_Delegate paint; private Paint_Delegate mPaint;
private char[] text; private char[] mText;
// Bounds of the text drawn so far. // Bounds of the text drawn so far.
private RectF bounds; private RectF mBounds;
private float mBaseline;
/** /**
* @param graphics May be null. * @param graphics May be null.
@ -65,9 +65,9 @@ public class BidiRenderer {
*/ */
/* package */ BidiRenderer(Graphics2D graphics, Paint_Delegate paint, char[] text) { /* package */ BidiRenderer(Graphics2D graphics, Paint_Delegate paint, char[] text) {
assert (paint != null); assert (paint != null);
this.graphics = graphics; mGraphics = graphics;
this.paint = paint; mPaint = paint;
this.text = text; mText = text;
} }
/** /**
@ -81,25 +81,26 @@ public class BidiRenderer {
* @param advances If not null, then advances for each character to be rendered are returned * @param advances If not null, then advances for each character to be rendered are returned
* here. * here.
* @param advancesIndex index into advances from where the advances need to be filled. * @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 * at the given co-ordinates
* @param x The x-coordinate of the left edge of where the text should be drawn on the given * @param x The x-coordinate of the left edge of where the text should be drawn on the given
* graphics. * 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. * @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) { 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 // We break the text into scripts and then select font based on it and then render each of
// the script runs. // the script runs.
bounds = new RectF(x, y, x, y); mBounds = new RectF(x, y, x, y);
for (ScriptRun run : getScriptRuns(text, start, limit, isRtl, paint.getFonts())) { mBaseline = y;
for (ScriptRun run : getScriptRuns(mText, start, limit, isRtl, mPaint.getFonts())) {
int flag = Font.LAYOUT_NO_LIMIT_CONTEXT | Font.LAYOUT_NO_START_CONTEXT; int flag = Font.LAYOUT_NO_LIMIT_CONTEXT | Font.LAYOUT_NO_START_CONTEXT;
flag |= isRtl ? Font.LAYOUT_RIGHT_TO_LEFT : Font.LAYOUT_LEFT_TO_RIGHT; flag |= isRtl ? Font.LAYOUT_RIGHT_TO_LEFT : Font.LAYOUT_LEFT_TO_RIGHT;
renderScript(run.start, run.limit, run.font, flag, advances, advancesIndex, draw); renderScript(run.start, run.limit, run.font, flag, advances, advancesIndex, draw);
advancesIndex += run.limit - run.start; advancesIndex += run.limit - run.start;
} }
return bounds; return mBounds;
} }
/** /**
@ -108,20 +109,22 @@ public class BidiRenderer {
* be drawn using the preferred font. * be drawn using the preferred font.
*/ */
private void renderScript(int start, int limit, FontInfo preferredFont, int flag, private void renderScript(int start, int limit, FontInfo preferredFont, int flag,
float advances[], int advancesIndex, boolean draw) { float[] advances, int advancesIndex, boolean draw) {
List<FontInfo> fonts = paint.getFonts(); List<FontInfo> fonts = mPaint.getFonts();
if (fonts == null || preferredFont == null) { if (fonts == null || preferredFont == null) {
return; return;
} }
while (start < limit) { while (start < limit) {
boolean foundFont = false; boolean foundFont = false;
int canDisplayUpTo = preferredFont.mFont.canDisplayUpTo(text, start, limit); int canDisplayUpTo = preferredFont.mFont.canDisplayUpTo(mText, start, limit);
if (canDisplayUpTo == -1) { if (canDisplayUpTo == -1) {
// We can draw all characters in the text. // We can draw all characters in the text.
render(start, limit, preferredFont, flag, advances, advancesIndex, draw); render(start, limit, preferredFont, flag, advances, advancesIndex, draw);
return; return;
} else if (canDisplayUpTo > start) { // can draw something }
if (canDisplayUpTo > start) {
// We can draw something.
render(start, canDisplayUpTo, preferredFont, flag, advances, advancesIndex, draw); render(start, canDisplayUpTo, preferredFont, flag, advances, advancesIndex, draw);
advancesIndex += canDisplayUpTo - start; advancesIndex += canDisplayUpTo - start;
start = canDisplayUpTo; start = canDisplayUpTo;
@ -129,9 +132,9 @@ public class BidiRenderer {
// The current character cannot be drawn with the preferred font. Cycle through all the // The current character cannot be drawn with the preferred font. Cycle through all the
// fonts to check which one can draw it. // 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) { for (FontInfo font : fonts) {
canDisplayUpTo = font.mFont.canDisplayUpTo(text, start, start + charCount); canDisplayUpTo = font.mFont.canDisplayUpTo(mText, start, start + charCount);
if (canDisplayUpTo == -1) { if (canDisplayUpTo == -1) {
render(start, start+charCount, font, flag, advances, advancesIndex, draw); render(start, start+charCount, font, flag, advances, advancesIndex, draw);
start += charCount; 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) { int advancesIndex, boolean draw) {
// Since the metrics don't have anti-aliasing set, we create a new FontRenderContext with // Since the metrics don't have anti-aliasing set, we create a new FontRenderContext with
// the anti-aliasing set. // the anti-aliasing set.
FontRenderContext f = font.mMetrics.getFontRenderContext(); FontRenderContext f = font.mMetrics.getFontRenderContext();
FontRenderContext frc = new FontRenderContext(f.getTransform(), paint.isAntiAliased(), FontRenderContext frc = new FontRenderContext(f.getTransform(), mPaint.isAntiAliased(),
f.usesFractionalMetrics()); 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 ng = gv.getNumGlyphs();
int[] ci = gv.getGlyphCharIndices(0, ng, null); int[] ci = gv.getGlyphCharIndices(0, ng, null);
for (int i = 0; i < ng; i++) { if (advances != null) {
float adv = gv.getGlyphMetrics(i).getAdvanceX(); for (int i = 0; i < ng; i++) {
if (advances != null) {
int adv_idx = advancesIndex + ci[i]; int adv_idx = advancesIndex + ci[i];
advances[adv_idx] += adv; advances[adv_idx] += gv.getGlyphMetrics(i).getAdvanceX();
} }
} }
if (draw && graphics != null) { if (draw && mGraphics != null) {
graphics.drawGlyphVector(gv, bounds.right, bounds.bottom); mGraphics.drawGlyphVector(gv, mBounds.right, mBaseline);
} }
Rectangle2D awtBounds = gv.getVisualBounds();
RectF visualBounds = awtRectToAndroidRect(awtBounds, bounds.right, bounds.bottom); // Update the bounds.
// If the width of the bounds is zero, no text has been drawn yet. Hence, use the Rectangle2D awtBounds = gv.getLogicalBounds();
// coordinates from the bounds as an offset only. RectF bounds = awtRectToAndroidRect(awtBounds, mBounds.right, mBaseline);
if (Math.abs(bounds.right - bounds.left) == 0) { // If the width of the bounds is zero, no text had been drawn earlier. Hence, use the
bounds = visualBounds; // coordinates from the bounds as an offset.
if (Math.abs(mBounds.right - mBounds.left) == 0) {
mBounds = bounds;
} else { } 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 left = (float) awtRec.getX();
float top = (float) awtRec.getY(); float top = (float) awtRec.getY();
float right = (float) (left + awtRec.getWidth()); float right = (float) (left + awtRec.getWidth());
@ -198,8 +205,6 @@ public class BidiRenderer {
return androidRect; return androidRect;
} }
// --- Static helper methods ---
/* package */ static List<ScriptRun> getScriptRuns(char[] text, int start, int limit, /* package */ static List<ScriptRun> getScriptRuns(char[] text, int start, int limit,
boolean isRtl, List<FontInfo> fonts) { boolean isRtl, List<FontInfo> fonts) {
LinkedList<ScriptRun> scriptRuns = new LinkedList<ScriptRun>(); LinkedList<ScriptRun> scriptRuns = new LinkedList<ScriptRun>();