Optimize text GL setup

Only performs the GL setup steps when at least one glyph is drawn.
This change also skips various draw operations when the specified
paint draws with alpha = 0.

Change-Id: I9eda148b0503acffc552ee19196f5d52e958a1a2

1 files changed, 66 insertions, 48 deletions

diff --git a/libs/hwui/OpenGLRenderer.cpp b/libs/hwui/OpenGLRenderer.cpp
index 8030d6672851..e7dfa666e2ab 100644
--- a/libs/hwui/OpenGLRenderer.cpp
+++ b/libs/hwui/OpenGLRenderer.cpp
@@ -1726,7 +1726,7 @@ void OpenGLRenderer::setupDrawSimpleMesh() {
 }
 
 void OpenGLRenderer::setupDrawTexture(GLuint texture) {
-    bindTexture(texture);
+    if (texture) bindTexture(texture);
     mTextureUnit++;
     mCaches.enableTexCoordsVertexArray();
 }
@@ -2385,7 +2385,8 @@ status_t OpenGLRenderer::drawShape(float left, float top, const PathTexture* tex
 
 status_t OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
         float rx, float ry, SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
+            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
         return DrawGlInfo::kStatusDone;
     }
 
@@ -2410,7 +2411,8 @@ status_t OpenGLRenderer::drawRoundRect(float left, float top, float right, float
 
 status_t OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* p) {
     if (mSnapshot->isIgnored() || quickRejectPreStroke(x - radius, y - radius,
-            x + radius, y + radius, p)) {
+            x + radius, y + radius, p) ||
+            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
         return DrawGlInfo::kStatusDone;
     }
     if (p->getPathEffect() != 0) {
@@ -2430,7 +2432,8 @@ status_t OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* p)
 
 status_t OpenGLRenderer::drawOval(float left, float top, float right, float bottom,
         SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
+            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
         return DrawGlInfo::kStatusDone;
     }
 
@@ -2451,7 +2454,8 @@ status_t OpenGLRenderer::drawOval(float left, float top, float right, float bott
 
 status_t OpenGLRenderer::drawArc(float left, float top, float right, float bottom,
         float startAngle, float sweepAngle, bool useCenter, SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
+            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
         return DrawGlInfo::kStatusDone;
     }
 
@@ -2487,7 +2491,8 @@ status_t OpenGLRenderer::drawArc(float left, float top, float right, float botto
 #define SkPaintDefaults_MiterLimit SkIntToScalar(4)
 
 status_t OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p) ||
+            (p->getAlpha() == 0 && getXfermode(p->getXfermode()) != SkXfermode::kClear_Mode)) {
         return DrawGlInfo::kStatusDone;
     }
 
@@ -2563,6 +2568,48 @@ bool OpenGLRenderer::canSkipText(const SkPaint* paint) const {
     return alpha == 0.0f && getXfermode(paint->getXfermode()) == SkXfermode::kSrcOver_Mode;
 }
 
+class TextSetupFunctor: public Functor {
+public:
+    TextSetupFunctor(OpenGLRenderer& renderer, float x, float y, bool pureTranslate,
+            int alpha, SkXfermode::Mode mode, SkPaint* paint): Functor(),
+            renderer(renderer), x(x), y(y), pureTranslate(pureTranslate),
+            alpha(alpha), mode(mode), paint(paint) {
+    }
+    ~TextSetupFunctor() { }
+
+    status_t operator ()(int what, void* data) {
+        renderer.setupDraw();
+        renderer.setupDrawTextGamma(paint);
+        renderer.setupDrawDirtyRegionsDisabled();
+        renderer.setupDrawWithTexture(true);
+        renderer.setupDrawAlpha8Color(paint->getColor(), alpha);
+        renderer.setupDrawColorFilter();
+        renderer.setupDrawShader();
+        renderer.setupDrawBlending(true, mode);
+        renderer.setupDrawProgram();
+        renderer.setupDrawModelView(x, y, x, y, pureTranslate, true);
+        // Calling setupDrawTexture with the name 0 will enable the
+        // uv attributes and increase the texture unit count
+        // texture binding will be performed by the font renderer as
+        // needed
+        renderer.setupDrawTexture(0);
+        renderer.setupDrawPureColorUniforms();
+        renderer.setupDrawColorFilterUniforms();
+        renderer.setupDrawShaderUniforms(pureTranslate);
+        renderer.setupDrawTextGammaUniforms();
+
+        return NO_ERROR;
+    }
+
+    OpenGLRenderer& renderer;
+    float x;
+    float y;
+    bool pureTranslate;
+    int alpha;
+    SkXfermode::Mode mode;
+    SkPaint* paint;
+};
+
 status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count,
         const float* positions, SkPaint* paint) {
     if (text == NULL || count == 0 || mSnapshot->isIgnored() || canSkipText(paint)) {
@@ -2599,31 +2646,16 @@ status_t OpenGLRenderer::drawPosText(const char* text, int bytesCount, int count
     if (pureTranslate && !linearFilter) {
         linearFilter = fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
     }
-
-    mCaches.activeTexture(0);
-    setupDraw();
-    setupDrawTextGamma(paint);
-    setupDrawDirtyRegionsDisabled();
-    setupDrawWithTexture(true);
-    setupDrawAlpha8Color(paint->getColor(), alpha);
-    setupDrawColorFilter();
-    setupDrawShader();
-    setupDrawBlending(true, mode);
-    setupDrawProgram();
-    setupDrawModelView(x, y, x, y, pureTranslate, true);
-    setupDrawTexture(fontRenderer.getTexture(linearFilter));
-    setupDrawPureColorUniforms();
-    setupDrawColorFilterUniforms();
-    setupDrawShaderUniforms(pureTranslate);
-    setupDrawTextGammaUniforms();
+    fontRenderer.setTextureFiltering(linearFilter);
 
     const Rect* clip = pureTranslate ? mSnapshot->clipRect : &mSnapshot->getLocalClip();
     Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
 
     const bool hasActiveLayer = hasLayer();
 
+    TextSetupFunctor functor(*this, x, y, pureTranslate, alpha, mode, paint);
     if (fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
-            positions, hasActiveLayer ? &bounds : NULL)) {
+            positions, hasActiveLayer ? &bounds : NULL, &functor)) {
         if (hasActiveLayer) {
             if (!pureTranslate) {
                 currentTransform().mapRect(bounds);
@@ -2716,40 +2748,22 @@ status_t OpenGLRenderer::drawText(const char* text, int bytesCount, int count,
 
     // Pick the appropriate texture filtering
     bool linearFilter = !pureTranslate || fabs(y - (int) y) > 0.0f || fabs(x - (int) x) > 0.0f;
-
-    // The font renderer will always use texture unit 0
-    mCaches.activeTexture(0);
-    setupDraw();
-    setupDrawTextGamma(paint);
-    setupDrawDirtyRegionsDisabled();
-    setupDrawWithTexture(true);
-    setupDrawAlpha8Color(paint->getColor(), alpha);
-    setupDrawColorFilter();
-    setupDrawShader();
-    setupDrawBlending(true, mode);
-    setupDrawProgram();
-    setupDrawModelView(x, y, x, y, pureTranslate, true);
-    // See comment above; the font renderer must use texture unit 0
-    // assert(mTextureUnit == 0)
-    setupDrawTexture(fontRenderer.getTexture(linearFilter));
-    setupDrawPureColorUniforms();
-    setupDrawColorFilterUniforms();
-    setupDrawShaderUniforms(pureTranslate);
-    setupDrawTextGammaUniforms();
+    fontRenderer.setTextureFiltering(linearFilter);
 
     // TODO: Implement better clipping for scaled/rotated text
     const Rect* clip = !pureTranslate ? NULL : mSnapshot->clipRect;
     Rect bounds(FLT_MAX / 2.0f, FLT_MAX / 2.0f, FLT_MIN / 2.0f, FLT_MIN / 2.0f);
 
     bool status;
+    TextSetupFunctor functor(*this, x, y, pureTranslate, alpha, mode, paint);
     if (CC_UNLIKELY(paint->getTextAlign() != SkPaint::kLeft_Align)) {
         SkPaint paintCopy(*paint);
         paintCopy.setTextAlign(SkPaint::kLeft_Align);
         status = fontRenderer.renderPosText(&paintCopy, clip, text, 0, bytesCount, count, x, y,
-                positions, hasActiveLayer ? &bounds : NULL);
+                positions, hasActiveLayer ? &bounds : NULL, &functor);
     } else {
         status = fontRenderer.renderPosText(paint, clip, text, 0, bytesCount, count, x, y,
-                positions, hasActiveLayer ? &bounds : NULL);
+                positions, hasActiveLayer ? &bounds : NULL, &functor);
     }
 
     if (status && hasActiveLayer) {
@@ -2772,12 +2786,12 @@ status_t OpenGLRenderer::drawTextOnPath(const char* text, int bytesCount, int co
 
     FontRenderer& fontRenderer = mCaches.fontRenderer->getFontRenderer(paint);
     fontRenderer.setFont(paint, mat4::identity());
+    fontRenderer.setTextureFiltering(true);
 
     int alpha;
     SkXfermode::Mode mode;
     getAlphaAndMode(paint, &alpha, &mode);
 
-    mCaches.activeTexture(0);
     setupDraw();
     setupDrawTextGamma(paint);
     setupDrawDirtyRegionsDisabled();
@@ -2788,7 +2802,11 @@ status_t OpenGLRenderer::drawTextOnPath(const char* text, int bytesCount, int co
     setupDrawBlending(true, mode);
     setupDrawProgram();
     setupDrawModelView(0.0f, 0.0f, 0.0f, 0.0f, false, true);
-    setupDrawTexture(fontRenderer.getTexture(true));
+    // Calling setupDrawTexture with the name 0 will enable the
+    // uv attributes and increase the texture unit count
+    // texture binding will be performed by the font renderer as
+    // needed
+    setupDrawTexture(0);
     setupDrawPureColorUniforms();
     setupDrawColorFilterUniforms();
     setupDrawShaderUniforms(false);