Add drop shadow for drawPosText in hwui renderer.

This patch adds support for drop shadows (setShadowLayer) for
drawPosText in the hwui renderer. In and of itself, it's not very
important, but it's on the critical path for correct mark positioning,
tracked as bug 5443796.

The change itself is fairly straightforward - it basically just adds an
extra "positions" argument to all draw and measure methods on the code
path for drawing drop shadowed text, as well as to the cache key for
cached shadow textures.

Change-Id: Ic1cb63299ba61ccbef31779459ecb82aa4a5e672

1 files changed, 44 insertions, 33 deletions

diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index a47d732..fe056b0 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -2294,6 +2294,44 @@ status_t OpenGLRenderer::drawRect(float left, float top, float right, float bott
     return DrawGlInfo::kStatusDrew;
 }
 
+void OpenGLRenderer::drawTextShadow(SkPaint* paint, const char* text, int bytesCount, int count,
+        const float* positions, FontRenderer& fontRenderer, int alpha, SkXfermode::Mode mode,
+        float x, float y) {
+    mCaches.activeTexture(0);
+
+    // NOTE: The drop shadow will not perform gamma correction
+    //       if shader-based correction is enabled
+    mCaches.dropShadowCache.setFontRenderer(fontRenderer);
+    const ShadowTexture* shadow = mCaches.dropShadowCache.get(
+            paint, text, bytesCount, count, mShadowRadius, positions);
+    const AutoTexture autoCleanup(shadow);
+
+    const float sx = x - shadow->left + mShadowDx;
+    const float sy = y - shadow->top + mShadowDy;
+
+    const int shadowAlpha = ((mShadowColor >> 24) & 0xFF) * mSnapshot->alpha;
+    int shadowColor = mShadowColor;
+    if (mShader) {
+        shadowColor = 0xffffffff;
+    }
+
+    setupDraw();
+    setupDrawWithTexture(true);
+    setupDrawAlpha8Color(shadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
+    setupDrawColorFilter();
+    setupDrawShader();
+    setupDrawBlending(true, mode);
+    setupDrawProgram();
+    setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height);
+    setupDrawTexture(shadow->id);
+    setupDrawPureColorUniforms();
+    setupDrawColorFilterUniforms();
+    setupDrawShaderUniforms();
+    setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
+
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
+}
+
 status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count,
         const float* positions, SkPaint* paint) {
     if (text == NULL || count == 0 || mSnapshot->isIgnored() ||
@@ -2322,6 +2360,11 @@ status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count
     SkXfermode::Mode mode;
     getAlphaAndMode(paint, &alpha, &mode);
 
+    if (CC_UNLIKELY(mHasShadow)) {
+        drawTextShadow(paint, text, bytesCount, count, positions, fontRenderer, alpha, mode,
+                0.0f, 0.0f);
+    }
+
     // Pick the appropriate texture filtering
     bool linearFilter = mSnapshot->transform->changesBounds();
     if (pureTranslate && !linearFilter) {
@@ -2415,39 +2458,7 @@ status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
     getAlphaAndMode(paint, &alpha, &mode);
 
     if (CC_UNLIKELY(mHasShadow)) {
-        mCaches.activeTexture(0);
-
-        // NOTE: The drop shadow will not perform gamma correction
-        //       if shader-based correction is enabled
-        mCaches.dropShadowCache.setFontRenderer(fontRenderer);
-        const ShadowTexture* shadow = mCaches.dropShadowCache.get(
-                paint, text, bytesCount, count, mShadowRadius);
-        const AutoTexture autoCleanup(shadow);
-
-        const float sx = oldX - shadow->left + mShadowDx;
-        const float sy = oldY - shadow->top + mShadowDy;
-
-        const int shadowAlpha = ((mShadowColor >> 24) & 0xFF) * mSnapshot->alpha;
-        int shadowColor = mShadowColor;
-        if (mShader) {
-            shadowColor = 0xffffffff;
-        }
-
-        setupDraw();
-        setupDrawWithTexture(true);
-        setupDrawAlpha8Color(shadowColor, shadowAlpha < 255 ? shadowAlpha : alpha);
-        setupDrawColorFilter();
-        setupDrawShader();
-        setupDrawBlending(true, mode);
-        setupDrawProgram();
-        setupDrawModelView(sx, sy, sx + shadow->width, sy + shadow->height);
-        setupDrawTexture(shadow->id);
-        setupDrawPureColorUniforms();
-        setupDrawColorFilterUniforms();
-        setupDrawShaderUniforms();
-        setupDrawMesh(NULL, (GLvoid*) gMeshTextureOffset);
-
-        glDrawArrays(GL_TRIANGLE_STRIP, 0, gMeshCount);
+        drawTextShadow(paint, text, bytesCount, count, NULL, fontRenderer, alpha, mode, oldX, oldY);
     }
 
     // Pick the appropriate texture filtering