commit c13bc571d3e61a43b87eb97f0719abd304cafaf2
author Florin Malita <fmalita@google.com> Fri Sep 26 10:33:37 2014 -0400
committer Florin Malita <fmalita@google.com> Fri Sep 26 10:33:37 2014 -0400
tree 819036c0fc5634ddf7784a036c0f1fe2ce914b9a
parent 2cce421bdf836ea269ddc98ffbb688acb8dd544e

Fix SkTextBlob offset semantics.

Implement proper x/y drawTextBlob() handling by plumbing a
drawPosText() offset parameter (to act as an additional glyph pos
translation) throughout the device layer.

The new offset superceeds the existing constY, with a minor semantic
tweak: whereas previous implementations were ignoring constY in 2D
positioning mode (scalarsPerGlyph == 2), now the offset is always
observed, in all positioning modes. We can do this because existing
drawPosText() clients always pass constY == 0 for full positioning mode.

R=reed@google.com, jvanverth@google.com, robertphillips@google.com

Review URL: https://codereview.chromium.org/605533002

src/gpu/GrStencilAndCoverTextContext.cpp

diff --git a/src/gpu/GrStencilAndCoverTextContext.cpp b/src/gpu/GrStencilAndCoverTextContext.cpp
index c1d9e9d..cfcabe9 100644
--- a/src/gpu/GrStencilAndCoverTextContext.cpp
+++ b/src/gpu/GrStencilAndCoverTextContext.cpp
@@ -54,7 +54,7 @@
     // will turn off the use of device-space glyphs when perspective transforms
     // are in use.
 
-    this->init(paint, skPaint, byteLength, kMaxAccuracy_RenderMode);
+    this->init(paint, skPaint, byteLength, kMaxAccuracy_RenderMode, SkPoint::Make(0, 0));
 
     // Transform our starting point.
     if (fNeedsDeviceSpaceGlyphs) {
@@ -123,8 +123,8 @@
                                                const char text[],
                                                size_t byteLength,
                                                const SkScalar pos[],
-                                               SkScalar constY,
-                                               int scalarsPerPosition) {
+                                               int scalarsPerPosition,
+                                               const SkPoint& offset) {
     SkASSERT(byteLength == 0 || text != NULL);
     SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);
 
@@ -141,8 +141,7 @@
     // transform is not part of SkPaint::measureText API, and thus we use the
     // same glyphs as what were measured.
 
-    const float textTranslateY = (1 == scalarsPerPosition ? constY : 0);
-    this->init(paint, skPaint, byteLength, kMaxPerformance_RenderMode, textTranslateY);
+    this->init(paint, skPaint, byteLength, kMaxPerformance_RenderMode, offset);
 
     SkDrawCacheProc glyphCacheProc = fSkPaint.getDrawCacheProc();
 
@@ -171,7 +170,7 @@
         }
     } else {
         fTransformType = GrPathRendering::kTranslate_PathTransformType;
-        SkTextMapStateProc tmsProc(SkMatrix::I(), 0, scalarsPerPosition);
+        SkTextMapStateProc tmsProc(SkMatrix::I(), SkPoint::Make(0, 0), scalarsPerPosition);
         SkTextAlignProcScalar alignProc(fSkPaint.getTextAlign());
         while (text < stop) {
             const SkGlyph& glyph = glyphCacheProc(fGlyphCache, &text, 0, 0);
@@ -242,7 +241,7 @@
                                         const SkPaint& skPaint,
                                         size_t textByteLength,
                                         RenderMode renderMode,
-                                        SkScalar textTranslateY) {
+                                        const SkPoint& textTranslate) {
     GrTextContext::init(paint, skPaint);
 
     fContextInitialMatrix = fContext->getMatrix();
@@ -258,7 +257,7 @@
     if (fNeedsDeviceSpaceGlyphs) {
         // SkDraw::ShouldDrawTextAsPaths takes care of perspective transforms.
         SkASSERT(!fContextInitialMatrix.hasPerspective());
-        SkASSERT(0 == textTranslateY); // TODO: Handle textTranslateY in device-space usecase.
+        SkASSERT(textTranslate.isZero()); // TODO: Handle textTranslate in device-space usecase.
 
         fTextRatio = fTextInverseRatio = 1.0f;
 
@@ -340,7 +339,7 @@
         }
 
         SkMatrix textMatrix;
-        textMatrix.setTranslate(0, textTranslateY);
+        textMatrix.setTranslate(textTranslate.x(), textTranslate.y());
         // Glyphs loaded by GPU path rendering have an inverted y-direction.
         textMatrix.preScale(fTextRatio, -fTextRatio);
         fPaint.localCoordChange(textMatrix);