commit b5f7826c51af2862aebcabe61e1ba684f925e488
author fmalita <fmalita@chromium.org> Wed Aug 06 13:07:15 2014 -0700
committer Commit bot <commit-bot@chromium.org> Wed Aug 06 13:07:15 2014 -0700
tree d4f679b74224259eaa59f57fd83fd7a984b4a22d
parent 3c7edda88e275bcdaeb5d3afd0428a21f1635d13

Explicit tile bounds for SkPictureShader

The integer picture size is not granular enough to allow precise tiling
in arbitrary coordinate systems. This CL adds an optional tile bounds
float rect param to control the tile size and location.

(this also allows tile spacing emulation for picture
shaders).

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

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/437393003

src/core/SkPictureShader.cpp

diff --git a/src/core/SkPictureShader.cpp b/src/core/SkPictureShader.cpp
index 6ea67f8..2a6aae5 100644
--- a/src/core/SkPictureShader.cpp
+++ b/src/core/SkPictureShader.cpp
@@ -19,16 +19,20 @@
 #endif
 
 SkPictureShader::SkPictureShader(const SkPicture* picture, TileMode tmx, TileMode tmy,
-                                 const SkMatrix* localMatrix)
+                                 const SkMatrix* localMatrix, const SkRect* tile)
     : INHERITED(localMatrix)
     , fPicture(SkRef(picture))
     , fTmx(tmx)
-    , fTmy(tmy) { }
+    , fTmy(tmy) {
+    fTile = tile ? *tile : SkRect::MakeWH(SkIntToScalar(picture->width()),
+                                          SkIntToScalar(picture->height()));
+}
 
 SkPictureShader::SkPictureShader(SkReadBuffer& buffer)
         : INHERITED(buffer) {
     fTmx = static_cast<SkShader::TileMode>(buffer.read32());
     fTmy = static_cast<SkShader::TileMode>(buffer.read32());
+    buffer.readRect(&fTile);
     fPicture = SkPicture::CreateFromBuffer(buffer);
 }
 
@@ -37,11 +41,12 @@
 }
 
 SkPictureShader* SkPictureShader::Create(const SkPicture* picture, TileMode tmx, TileMode tmy,
-                                         const SkMatrix* localMatrix) {
-    if (!picture || 0 == picture->width() || 0 == picture->height()) {
+                                         const SkMatrix* localMatrix, const SkRect* tile) {
+    if (!picture || 0 == picture->width() || 0 == picture->height()
+        || (NULL != tile && tile->isEmpty())) {
         return NULL;
     }
-    return SkNEW_ARGS(SkPictureShader, (picture, tmx, tmy, localMatrix));
+    return SkNEW_ARGS(SkPictureShader, (picture, tmx, tmy, localMatrix, tile));
 }
 
 void SkPictureShader::flatten(SkWriteBuffer& buffer) const {
@@ -49,6 +54,7 @@
 
     buffer.write32(fTmx);
     buffer.write32(fTmy);
+    buffer.writeRect(fTile);
     fPicture->flatten(buffer);
 }
 
@@ -68,7 +74,7 @@
         scale.set(SkScalarSqrt(m.getScaleX() * m.getScaleX() + m.getSkewX() * m.getSkewX()),
                   SkScalarSqrt(m.getScaleY() * m.getScaleY() + m.getSkewY() * m.getSkewY()));
     }
-    SkSize scaledSize = SkSize::Make(scale.x() * fPicture->width(), scale.y() * fPicture->height());
+    SkSize scaledSize = SkSize::Make(scale.x() * fTile.width(), scale.y() * fTile.height());
 
     SkISize tileSize = scaledSize.toRound();
     if (tileSize.isEmpty()) {
@@ -76,8 +82,8 @@
     }
 
     // The actual scale, compensating for rounding.
-    SkSize tileScale = SkSize::Make(SkIntToScalar(tileSize.width()) / fPicture->width(),
-                                    SkIntToScalar(tileSize.height()) / fPicture->height());
+    SkSize tileScale = SkSize::Make(SkIntToScalar(tileSize.width()) / fTile.width(),
+                                    SkIntToScalar(tileSize.height()) / fTile.height());
 
     SkAutoMutexAcquire ama(fCachedBitmapShaderMutex);
 
@@ -90,6 +96,7 @@
 
         SkCanvas canvas(bm);
         canvas.scale(tileScale.width(), tileScale.height());
+        canvas.translate(fTile.x(), fTile.y());
         canvas.drawPicture(fPicture);
 
         fCachedTileScale = tileScale;