Move distance field font code into SkGpuDevice

src/gpu/SkGpuDevice.cpp

Index: src/gpu/SkGpuDevice.cpp
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index c6194e70312a5710891b2317e07f61dae90d8ca9..e36d2c61c59fac20451d74f5c8cf2ad1dbb84925 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1684,9 +1684,6 @@ SkDrawProcs* SkGpuDevice::initDrawForText(GrTextContext* context) {
         fDrawProcs = SkNEW(GrSkDrawProcs);
         fDrawProcs->fD1GProc = SkGPU_Draw1Glyph;
         fDrawProcs->fContext = fContext;
-#if SK_DISTANCEFIELD_FONTS
-        fDrawProcs->fFlags = 0;
-#endif
     }
 
     // init our (and GL's) state
@@ -1700,9 +1697,12 @@ void SkGpuDevice::drawText(const SkDraw& draw, const void* text,
                           const SkPaint& paint) {
     CHECK_SHOULD_DRAW(draw, false);
 
-    if (fContext->getMatrix().hasPerspective()) {
-        // this guy will just call our drawPath()
-        draw.drawText((const char*)text, byteLength, x, y, paint);
+    if (draw.shouldDrawTextAsPaths(paint, fContext->getMatrix())) {
+        draw.drawText_asPaths((const char*)text, byteLength, x, y, paint);
+#if SK_DISTANCEFIELD_FONTS
+    } else if (!paint.getRasterizer()) {
+        drawDFText((const char *)text, byteLength, x, y, paint);
+#endif
     } else {
         SkDraw myDraw(draw);
 
@@ -1710,23 +1710,93 @@ void SkGpuDevice::drawText(const SkDraw& draw, const void* text,
         if (!skPaint2GrPaintShader(this, paint, true, &grPaint)) {
             return;
         }
-#if SK_DISTANCEFIELD_FONTS
-        if (paint.getRasterizer()) {
-#endif
-            GrBitmapTextContext context(fContext, grPaint, paint.getColor());
-            myDraw.fProcs = this->initDrawForText(&context);
-            this->INHERITED::drawText(myDraw, text, byteLength, x, y, paint);
-#if SK_DISTANCEFIELD_FONTS
-        } else {
-            GrDistanceFieldTextContext context(fContext, grPaint, paint.getColor(),
-                                               paint.getTextSize()/SkDrawProcs::kBaseDFFontSize);
-            myDraw.fProcs = this->initDrawForText(&context);
-            fDrawProcs->fFlags |= SkDrawProcs::kSkipBakedGlyphTransform_Flag;
-            fDrawProcs->fFlags |= SkDrawProcs::kUseScaledGlyphs_Flag;
-            this->INHERITED::drawText(myDraw, text, byteLength, x, y, paint);
-            fDrawProcs->fFlags = 0;
-       }
-#endif
+
+        GrBitmapTextContext context(fContext, grPaint, paint.getColor());
+        myDraw.fProcs = this->initDrawForText(&context);
+        this->INHERITED::drawText(myDraw, text, byteLength, x, y, paint);
+    }
+}
+
+static const int kBaseDFFontSize = 32;
+
+void SkGpuDevice::drawDFText(const char text[], size_t byteLength, 
+                             SkScalar x, SkScalar y,
+                             const SkPaint& paint) {
+    GrPaint grPaint;
+    if (!skPaint2GrPaintShader(this, paint, true, &grPaint)) {
+        return;
+    }
+
+    SkASSERT(byteLength == 0 || text != NULL);
+
+    SkDEBUGCODE(this->validate();)
+
+    // nothing to draw
+    if (text == NULL || byteLength == 0 /* no raster clip? || fRC->isEmpty()*/) {
+        return;
+    }
+
+    SkScalar sizeRatio = paint.getTextSize()/kBaseDFFontSize;
+    GrDistanceFieldTextContext context(fContext, grPaint, paint.getColor(), sizeRatio);
+
+    SkDrawCacheProc glyphCacheProc = paint.getDrawCacheProc();
+
+    SkPaint paintCopy = paint;
+    paintCopy.setTextSize(SkIntToScalar(kBaseDFFontSize));
+    paintCopy.setLCDRenderText(false);
+    paintCopy.setAutohinted(false);
+    paintCopy.setSubpixelText(false);
+    SkAutoGlyphCache    autoCache(paintCopy, &this->fLeakyProperties, NULL);
+    SkGlyphCache*       cache = autoCache.getCache();
+ 
+    // need to measure first 
+    // TODO - generate positions and pre-load cache as well?
+    const char* stop = text + byteLength;
+    if (paint.getTextAlign() != SkPaint::kLeft_Align) {
+        SkFixed    stopX = 0;
+        SkFixed    stopY = 0;
+
+        const char* textPtr = text;
+        while (textPtr < stop) {
+            // don't need x, y here, since all subpixel variants will have the
+            // same advance
+            const SkGlyph& glyph = glyphCacheProc(cache, &textPtr, 0, 0);
+
+            stopX += glyph.fAdvanceX;
+            stopY += glyph.fAdvanceY;
+        }
+        SkASSERT(textPtr == stop);
+
+        SkScalar alignX = SkFixedToScalar(stopX)*sizeRatio;
+        SkScalar alignY = SkFixedToScalar(stopY)*sizeRatio;
+
+        if (paint.getTextAlign() == SkPaint::kCenter_Align) {
+            alignX = SkScalarHalf(alignX);
+            alignY = SkScalarHalf(alignY);
+        }
+
+        x -= alignX;
+        y -= alignY;
+    }
+
+    SkFixed fx = SkScalarToFixed(x) + SK_FixedHalf;
+    SkFixed fy = SkScalarToFixed(y) + SK_FixedHalf;
+    SkFixed fixedScale = SkScalarToFixed(sizeRatio);
+    GrFontScaler* fontScaler = get_gr_font_scaler(cache);
+    while (text < stop) {
+        const SkGlyph& glyph = glyphCacheProc(cache, &text, fx, fy);
+
+        if (glyph.fWidth) {
+            context.drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(),
+                                                  glyph.getSubXFixed(),
+                                                  glyph.getSubYFixed()),
+                                    SkFixedFloorToFixed(fx),
+                                    SkFixedFloorToFixed(fy),
+                                    fontScaler);
+        }
+
+        fx += SkFixedMul_portable(glyph.fAdvanceX, fixedScale);
+        fy += SkFixedMul_portable(glyph.fAdvanceY, fixedScale);
     }
 }
 
@@ -1736,10 +1806,14 @@ void SkGpuDevice::drawPosText(const SkDraw& draw, const void* text,
                              const SkPaint& paint) {
     CHECK_SHOULD_DRAW(draw, false);
 
-    if (fContext->getMatrix().hasPerspective()) {
+    if (draw.shouldDrawTextAsPaths(paint, fContext->getMatrix())) {
         // this guy will just call our drawPath()
-        draw.drawPosText((const char*)text, byteLength, pos, constY,
+        draw.drawPosText_asPaths((const char*)text, byteLength, pos, constY,
                          scalarsPerPos, paint);
+#if SK_DISTANCEFIELD_FONTS
+    } else if (!paint.getRasterizer()) {
+        drawPosDFText((const char *)text, byteLength, pos, constY, scalarsPerPos, paint);

[bsalomon, 2013/11/25 20:50:22]

this->

+#endif
     } else {
         SkDraw myDraw(draw);
 
@@ -1747,25 +1821,86 @@ void SkGpuDevice::drawPosText(const SkDraw& draw, const void* text,
         if (!skPaint2GrPaintShader(this, paint, true, &grPaint)) {
             return;
         }
-#if SK_DISTANCEFIELD_FONTS
-        if (paint.getRasterizer()) {
-#endif
-            GrBitmapTextContext context(fContext, grPaint, paint.getColor());
-            myDraw.fProcs = this->initDrawForText(&context);
-            this->INHERITED::drawPosText(myDraw, text, byteLength, pos, constY,
-                                         scalarsPerPos, paint);
-#if SK_DISTANCEFIELD_FONTS
-        } else {
-            GrDistanceFieldTextContext context(fContext, grPaint, paint.getColor(),
-                                               paint.getTextSize()/SkDrawProcs::kBaseDFFontSize);
-            myDraw.fProcs = this->initDrawForText(&context);
-            fDrawProcs->fFlags |= SkDrawProcs::kSkipBakedGlyphTransform_Flag;
-            fDrawProcs->fFlags |= SkDrawProcs::kUseScaledGlyphs_Flag;
-            this->INHERITED::drawPosText(myDraw, text, byteLength, pos, constY,
-                                         scalarsPerPos, paint);
-            fDrawProcs->fFlags = 0;
+        GrBitmapTextContext context(fContext, grPaint, paint.getColor());
+        myDraw.fProcs = this->initDrawForText(&context);
+        this->INHERITED::drawPosText(myDraw, text, byteLength, pos, constY,
+                                        scalarsPerPos, paint);
+    }
+}
+
+void SkGpuDevice::drawPosDFText(const char text[], size_t byteLength, 
+                                const SkScalar pos[], SkScalar constY, int scalarsPerPosition,
+                                const SkPaint& paint) {
+    GrPaint grPaint;
+    if (!skPaint2GrPaintShader(this, paint, true, &grPaint)) {
+        return;
+    }
+
+    SkASSERT(byteLength == 0 || text != NULL);
+    SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);
+
+    SkDEBUGCODE(this->validate();)
+
+    // nothing to draw
+    if (text == NULL || byteLength == 0 /* no raster clip? || fRC->isEmpty()*/) {
+        return;
+    }
+
+    SkScalar sizeRatio = paint.getTextSize()/kBaseDFFontSize;
+    GrDistanceFieldTextContext context(fContext, grPaint, paint.getColor(), sizeRatio);
+
+    SkDrawCacheProc glyphCacheProc = paint.getDrawCacheProc();
+
+    SkPaint paintCopy = paint;
+    paintCopy.setTextSize(SkIntToScalar(kBaseDFFontSize));
+    paintCopy.setLCDRenderText(false);
+    paintCopy.setAutohinted(false);
+    paintCopy.setSubpixelText(false);
+    SkAutoGlyphCache    autoCache(paintCopy, &this->fLeakyProperties, NULL);
+    SkGlyphCache*       cache = autoCache.getCache();
+
+    const char*        stop = text + byteLength;
+    GrFontScaler* fontScaler = get_gr_font_scaler(cache);
+
+    if (SkPaint::kLeft_Align == paint.getTextAlign()) {
+        while (text < stop) {
+            // the last 2 parameters are ignored
+            const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
+
+            if (glyph.fWidth) {
+                SkScalar x = pos[0];
+                SkScalar y = scalarsPerPosition == 1 ? constY : pos[1];
+ 
+                context.drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(),
+                                                      glyph.getSubXFixed(),
+                                                      glyph.getSubYFixed()),
+                                        SkScalarToFixed(x) + SK_FixedHalf, //d1g.fHalfSampleX,
+                                        SkScalarToFixed(y) + SK_FixedHalf, //d1g.fHalfSampleY,
+                                        fontScaler);
+            }
+            pos += scalarsPerPosition;
+        }
+    } else {

[robertphillips, 2013/11/25 20:39:44]

Is all this duplicate code just for the shift?

+        int alignShift = SkPaint::kCenter_Align == paint.getTextAlign() ? 1 : 0;
+        while (text < stop) {
+            // the last 2 parameters are ignored
+            const SkGlyph& glyph = glyphCacheProc(cache, &text, 0, 0);
+
+            if (glyph.fWidth) {
+                SkScalar x = pos[0];
+                SkScalar y = scalarsPerPosition == 1 ? constY : pos[1];
+
+                context.drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(),
+                                                      glyph.getSubXFixed(),
+                                                      glyph.getSubYFixed()),
+                                        SkScalarToFixed(x) - (glyph.fAdvanceX >> alignShift) 
+                                                           + SK_FixedHalf, //d1g.fHalfSampleX,
+                                        SkScalarToFixed(y) - (glyph.fAdvanceY >> alignShift) 
+                                                           + SK_FixedHalf, //d1g.fHalfSampleY,
+                                        fontScaler);
+            }
+            pos += scalarsPerPosition;
         }
-#endif
     }
 }