commit 624234f69b2a4781d24f3e4c6ae6450729e38397
author Romain Guy <romainguy@google.com> Tue Mar 05 16:43:31 2013 -0800
committer Romain Guy <romainguy@google.com> Tue Mar 05 18:12:35 2013 -0800
tree d6ae0bfd751e0e59329cb678c1d9f1cec447ee3e
parent 0b58a3deab66c30a8d35072e55aac6279dd367cc

Take only the scale params into account to rasterize text

This change extracts the scale parameters of the current transform
to pass then to the font renderer. Rotation and perspective are
applied to the generated mesh inside the vertex shader. This limits
the number of glyphs we have to create in the font cache and thus
reduces memory churn.

Change-Id: Ic5b3bae2b2b0e0250a8ee723b071a1709725c749

libs/hwui/font/Font.cpp

diff --git a/libs/hwui/font/Font.cpp b/libs/hwui/font/Font.cpp
index bf522b7..9307f11 100644
--- a/libs/hwui/font/Font.cpp
+++ b/libs/hwui/font/Font.cpp
@@ -53,10 +53,8 @@
     mStrokeWidth = paint->getStrokeWidth();
     mAntiAliasing = paint->isAntiAlias();
     mLookupTransform.reset();
-    mLookupTransform[SkMatrix::kMScaleX] = matrix.data[mat4::kScaleX];
-    mLookupTransform[SkMatrix::kMScaleY] = matrix.data[mat4::kScaleY];
-    mLookupTransform[SkMatrix::kMSkewX] = matrix.data[mat4::kSkewX];
-    mLookupTransform[SkMatrix::kMSkewY] = matrix.data[mat4::kSkewY];
+    mLookupTransform[SkMatrix::kMScaleX] = matrix[mat4::kScaleX];
+    mLookupTransform[SkMatrix::kMScaleY] = matrix[mat4::kScaleY];
     if (!mLookupTransform.invert(&mInverseLookupTransform)) {
         ALOGW("Could not query the inverse lookup transform for this font");
     }
@@ -81,8 +79,6 @@
     hash = JenkinsHashMix(hash, int(mAntiAliasing));
     hash = JenkinsHashMix(hash, android::hash_type(mLookupTransform[SkMatrix::kMScaleX]));
     hash = JenkinsHashMix(hash, android::hash_type(mLookupTransform[SkMatrix::kMScaleY]));
-    hash = JenkinsHashMix(hash, android::hash_type(mLookupTransform[SkMatrix::kMSkewX]));
-    hash = JenkinsHashMix(hash, android::hash_type(mLookupTransform[SkMatrix::kMSkewY]));
     return JenkinsHashWhiten(hash);
 }
 
@@ -122,16 +118,6 @@
     if (lhs.mLookupTransform[SkMatrix::kMScaleY] >
             rhs.mLookupTransform[SkMatrix::kMScaleY]) return +1;
 
-    if (lhs.mLookupTransform[SkMatrix::kMSkewX] <
-            rhs.mLookupTransform[SkMatrix::kMSkewX]) return -1;
-    if (lhs.mLookupTransform[SkMatrix::kMSkewX] >
-            rhs.mLookupTransform[SkMatrix::kMSkewX]) return +1;
-
-    if (lhs.mLookupTransform[SkMatrix::kMSkewY] <
-            rhs.mLookupTransform[SkMatrix::kMSkewY]) return -1;
-    if (lhs.mLookupTransform[SkMatrix::kMSkewY] >
-            rhs.mLookupTransform[SkMatrix::kMSkewY]) return +1;
-
     return 0;
 }
 
@@ -185,7 +171,7 @@
             nPenX, nPenY - height, u1, v1, glyph->mCacheTexture);
 }
 
-void Font::drawCachedGlyphPerspective(CachedGlyphInfo* glyph, int x, int y,
+void Font::drawCachedGlyphTransformed(CachedGlyphInfo* glyph, int x, int y,
         uint8_t* bitmap, uint32_t bitmapW, uint32_t bitmapH, Rect* bounds, const float* pos) {
     SkPoint p[4];
     p[0].iset(glyph->mBitmapLeft, glyph->mBitmapTop + glyph->mBitmapHeight);
@@ -388,18 +374,17 @@
 
     static RenderGlyph gRenderGlyph[] = {
             &android::uirenderer::Font::drawCachedGlyph,
-            &android::uirenderer::Font::drawCachedGlyphPerspective,
+            &android::uirenderer::Font::drawCachedGlyphTransformed,
             &android::uirenderer::Font::drawCachedGlyphBitmap,
             &android::uirenderer::Font::drawCachedGlyphBitmap,
             &android::uirenderer::Font::measureCachedGlyph,
             &android::uirenderer::Font::measureCachedGlyph
     };
-    RenderGlyph render = gRenderGlyph[(mode << 1) + mTransform.isPerspective()];
+    RenderGlyph render = gRenderGlyph[(mode << 1) + !mIdentityTransform];
 
     text += start;
     int glyphsCount = 0;
 
-    const bool applyTransform = !mTransform.isIdentity() && !mTransform.isPerspective();
     const SkPaint::Align align = paint->getTextAlign();
 
     while (glyphsCount < numGlyphs) {
@@ -418,10 +403,6 @@
             float penX = x + positions[(glyphsCount << 1)];
             float penY = y + positions[(glyphsCount << 1) + 1];
 
-            if (applyTransform) {
-                mTransform.mapPoint(penX, penY);
-            }
-
             (*this.*render)(cachedGlyph, roundf(penX), roundf(penY),
                     bitmap, bitmapW, bitmapH, bounds, positions);
         }
@@ -495,7 +476,7 @@
         font = new Font(state, description);
         state->mActiveFonts.put(description, font);
     }
-    font->mTransform.load(matrix);
+    font->mIdentityTransform = matrix.isIdentity();
 
     return font;
 }