Properly scale text

This change does not apply to drawPosText() and drawTextOnPath() yet.

Prior to this change, glyphs were always rasterized based on the
font size specified in the paint. All transforms were then applied
on the resulting texture. This creates rather ugly results when
text is scaled and/or rotated.

With this change, the font renderer will apply the current transform
matrix to the glyph before they are rasterized. This generates much
better looking results.

Change-Id: I0141b6ff18db35e1213e7a3ab9db1ecaf03d7a9c

1 files changed, 19 insertions, 27 deletions

diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index d683c272bdcc..fb77ef610fd0 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -1657,13 +1657,13 @@ void OpenGLRenderer::setupDrawModelViewTranslate(float left, float top, float ri
         mCaches.currentProgram->set(mOrthoMatrix, mModelView, *mSnapshot->transform);
         if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
     } else {
-        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
+        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mat4::identity());
         if (mTrackDirtyRegions) dirtyLayer(left, top, right, bottom);
     }
 }
 
 void OpenGLRenderer::setupDrawModelViewIdentity(bool offset) {
-    mCaches.currentProgram->set(mOrthoMatrix, mIdentity, *mSnapshot->transform, offset);
+    mCaches.currentProgram->set(mOrthoMatrix, mat4::identity(), *mSnapshot->transform, offset);
 }
 
 void OpenGLRenderer::setupDrawModelView(float left, float top, float right, float bottom,
@@ -1681,7 +1681,7 @@ void OpenGLRenderer::setupDrawModelView(float left, float top, float right, floa
             dirtyLayer(left, top, right, bottom, *mSnapshot->transform);
         }
     } else {
-        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mIdentity);
+        mCaches.currentProgram->set(mOrthoMatrix, mModelView, mat4::identity());
         if (mTrackDirtyRegions && dirty) dirtyLayer(left, top, right, bottom);
     }
 }
@@ -1716,7 +1716,7 @@ void OpenGLRenderer::setupDrawShaderUniforms(bool ignoreTransform) {
 void OpenGLRenderer::setupDrawShaderIdentityUniforms() {
     if (mDrawModifiers.mShader) {
         mDrawModifiers.mShader->setupProgram(mCaches.currentProgram,
-                mIdentity, *mSnapshot, &mTextureUnit);
+                mat4::identity(), *mSnapshot, &mTextureUnit);
     }
 }
 
@@ -2587,7 +2587,7 @@ status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count
     }
 
     FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
-    fontRenderer.setFont(paint, *mSnapshot->transform);
+    fontRenderer.setFont(paint, mat4::identity());
 
     int alpha;
     SkXfermode::Mode mode;
@@ -2663,17 +2663,10 @@ status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
         return DrawGlInfo::kStatusDone;
     }
 
-#if DEBUG_GLYPHS
-    ALOGD("OpenGLRenderer drawText() with FontID=%d",
-            SkTypeface::UniqueID(paint->getTypeface()));
-#endif
-
-    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
-    fontRenderer.setFont(paint, *mSnapshot->transform);
-
     const float oldX = x;
     const float oldY = y;
     const bool pureTranslate = mSnapshot->transform->isPureTranslate();
+
     if (CC_LIKELY(pureTranslate)) {
         x = (int) floorf(x + mSnapshot->transform->getTranslateX() + 0.5f);
         y = (int) floorf(y + mSnapshot->transform->getTranslateY() + 0.5f);
@@ -2683,16 +2676,19 @@ status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
     SkXfermode::Mode mode;
     getAlphaAndMode(paint, &alpha, &mode);
 
+    FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
+
     if (CC_UNLIKELY(mDrawModifiers.mHasShadow)) {
-        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer, alpha, mode,
-                oldX, oldY);
+        fontRenderer.setFont(paint, mat4::identity());
+        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer,
+                alpha, mode, oldX, oldY);
     }
 
+    fontRenderer.setFont(paint, pureTranslate ? mat4::identity() : *mSnapshot->transform);
+
     // Pick the appropriate texture filtering
-    bool linearFilter = mSnapshot->transform->changesBounds();
-    if (pureTranslate && !linearFilter) {
-        linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
-    }
+    bool linearFilter = !mSnapshot->transform->isPureTranslate() ||
+            fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
 
     // The font renderer will always use texture unit 0
     mCaches.activeTexture(0);
@@ -2705,17 +2701,16 @@ status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
     setupDrawShader();
     setupDrawBlending(true, mode);
     setupDrawProgram();
-    setupDrawModelView(x, y, x, y, pureTranslate, true);
+    setupDrawModelView(x, y, x, y, true, true);
     // See comment above; the font renderer must use texture unit 0
     // assert(mTextureUnit == 0)
     setupDrawTexture(fontRenderer.getTexture(linearFilter));
     setupDrawPureColorUniforms();
     setupDrawColorFilterUniforms();
-    setupDrawShaderUniforms(pureTranslate);
+    setupDrawShaderUniforms(true);
     setupDrawTextGammaUniforms();
 
-    const Rect* clip = pureTranslate ? mSnapshot->clipRect :
-            (mSnapshot->hasPerspectiveTransform() ? NULL : &mSnapshot->getLocalClip());
+    const Rect* clip = mSnapshot->hasPerspectiveTransform() ? NULL : mSnapshot->clipRect;
     Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
 
     const bool hasActiveLayer = hasLayer();
@@ -2732,9 +2727,6 @@ status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
     }
 
     if (status && hasActiveLayer) {
-        if (!pureTranslate) {
-            mSnapshot->transform->mapRect(bounds);
-        }
         dirtyLayerUnchecked(bounds, getRegion());
     }
 
@@ -2750,7 +2742,7 @@ status_t OpenGLRenderer::drawTextOnPath(const char* text, int bytesCount, int co
     }
 
     FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
-    fontRenderer.setFont(paint, *mSnapshot->transform);
+    fontRenderer.setFont(paint, mat4::identity());
 
     int alpha;
     SkXfermode::Mode mode;