Use combined color/coverage attribute when possible in aa rect renderer.

src/gpu/GrAARectRenderer.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAARectRenderer.h"
 #include "GrGpu.h"
 #include "gl/GrGLEffect.h"
@@ skipping 237 matching lines @@
 GrEffect* GrRectEffect::TestCreate(SkRandom* random,
                                    GrContext* context,
                                    const GrDrawTargetCaps&,
                                    GrTexture* textures[]) {
     return GrRectEffect::Create();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 namespace {
-
 extern const GrVertexAttrib gAARectAttribs[] = {
     {kVec2f_GrVertexAttribType,  0,                                 kPosition_GrVertexAttribBinding},
     {kVec4ub_GrVertexAttribType, sizeof(SkPoint),                   kColor_GrVertexAttribBinding},
     {kVec4ub_GrVertexAttribType, sizeof(SkPoint) + sizeof(SkColor), kCoverage_GrVertexAttribBinding},
 };
 
+// Should the coverage be multiplied into the color attrib or use a separate attrib.
+enum CoverageAttribType {
+    kUseColor_CoverageAttribType,
+    kUseCoverage_CoverageAttribType,
+};
+}
+
+static CoverageAttribType set_rect_attribs(GrDrawState* drawState) {
+    if (drawState->canTweakAlphaForCoverage()) {
+        drawState->setVertexAttribs<gAARectAttribs>(2);
+        return kUseColor_CoverageAttribType;
+    } else {
+        drawState->setVertexAttribs<gAARectAttribs>(3);
+        return kUseCoverage_CoverageAttribType;
+    }
+}
+
 static void set_inset_fan(SkPoint* pts, size_t stride,
                           const SkRect& r, SkScalar dx, SkScalar dy) {
     pts->setRectFan(r.fLeft + dx, r.fTop + dy,
                     r.fRight - dx, r.fBottom - dy, stride);
 }
 
-};
-
 void GrAARectRenderer::reset() {
     SkSafeSetNull(fAAFillRectIndexBuffer);
     SkSafeSetNull(fAAMiterStrokeRectIndexBuffer);
     SkSafeSetNull(fAABevelStrokeRectIndexBuffer);
 }
 
 static const uint16_t gFillAARectIdx[] = {
     0, 1, 5, 5, 4, 0,
     1, 2, 6, 6, 5, 1,
     2, 3, 7, 7, 6, 2,
@@ skipping 154 matching lines @@
 
 void GrAARectRenderer::geometryFillAARect(GrGpu* gpu,
                                           GrDrawTarget* target,
                                           const SkRect& rect,
                                           const SkMatrix& combinedMatrix,
                                           const SkRect& devRect) {
     GrDrawState* drawState = target->drawState();
 
     GrColor color = drawState->getColor();
 
-    drawState->setVertexAttribs<gAARectAttribs>(SK_ARRAY_COUNT(gAARectAttribs));
-    if (GrColorIsOpaque(color)) {
+    CoverageAttribType covAttribType = set_rect_attribs(drawState);
+    if (kUseCoverage_CoverageAttribType == covAttribType && GrColorIsOpaque(color)) {
         drawState->setHint(GrDrawState::kVertexColorsAreOpaque_Hint, true);
     }
 
     GrDrawTarget::AutoReleaseGeometry geo(target, 8, 0);
     if (!geo.succeeded()) {
         GrPrintf("Failed to get space for vertices!\n");
         return;
     }
 
     GrIndexBuffer* indexBuffer = this->aaFillRectIndexBuffer(gpu);
     if (NULL == indexBuffer) {
         GrPrintf("Failed to create index buffer!\n");
         return;
     }
 
     intptr_t verts = reinterpret_cast<intptr_t>(geo.vertices());
     size_t vsize = drawState->getVertexSize();
-    SkASSERT(sizeof(SkPoint) + 2 * sizeof(GrColor) == vsize);
 
     SkPoint* fan0Pos = reinterpret_cast<SkPoint*>(verts);
     SkPoint* fan1Pos = reinterpret_cast<SkPoint*>(verts + 4 * vsize);
 
     SkScalar inset = SkMinScalar(devRect.width(), SK_Scalar1);
     inset = SK_ScalarHalf * SkMinScalar(inset, devRect.height());
 
     if (combinedMatrix.rectStaysRect()) {
         // Temporarily #if'ed out. We don't want to pass in the devRect but
         // right now it is computed in GrContext::apply_aa_to_rect and we don't
@@ skipping 39 matching lines @@
         *((SkPoint*)((intptr_t)fan0Pos + 2 * vsize)) += vec[0] + vec[1];
         // TR
         *((SkPoint*)((intptr_t)fan1Pos + 3 * vsize)) =
             *((SkPoint*)((intptr_t)fan0Pos + 3 * vsize)) - vec[0] + vec[1];
         *((SkPoint*)((intptr_t)fan0Pos + 3 * vsize)) += vec[0] - vec[1];
     }
 
     // Make verts point to vertex color and then set all the color and coverage vertex attrs values.
     verts += sizeof(SkPoint);
     for (int i = 0; i < 4; ++i) {
-        *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
-        *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = 0;
+        if (kUseCoverage_CoverageAttribType == covAttribType) {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
+            *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = 0;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = 0;
+        }
     }
 
     int scale;
     if (inset < SK_ScalarHalf) {
         scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
         SkASSERT(scale >= 0 && scale <= 255);
     } else {
         scale = 0xff;
     }
 
     GrColor innerCoverage;
-    innerCoverage = GrColorPackRGBA(scale, scale, scale, scale);    verts += 4 * vsize;
+    if (kUseCoverage_CoverageAttribType == covAttribType) {
+        innerCoverage = GrColorPackRGBA(scale, scale, scale, scale); 
+    } else {
+        innerCoverage = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
+    }
+    verts += 4 * vsize;
     for (int i = 0; i < 4; ++i) {
-        *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
-        *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = innerCoverage;
+        if (kUseCoverage_CoverageAttribType == covAttribType) {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
+            *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = innerCoverage;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = innerCoverage;
+        }
     }
 
     target->setIndexSourceToBuffer(indexBuffer);
     target->drawIndexedInstances(kTriangles_GrPrimitiveType, 1,
                                  kVertsPerAAFillRect,
                                  kIndicesPerAAFillRect);
     target->resetIndexSource();
 }
 
 namespace {
@@ skipping 219 matching lines @@
 }
 
 void GrAARectRenderer::geometryStrokeAARect(GrGpu* gpu,
                                             GrDrawTarget* target,
                                             const SkRect& devOutside,
                                             const SkRect& devOutsideAssist,
                                             const SkRect& devInside,
                                             bool miterStroke) {
     GrDrawState* drawState = target->drawState();
 
-    drawState->setVertexAttribs<gAARectAttribs>(SK_ARRAY_COUNT(gAARectAttribs));
+    CoverageAttribType covAttribType = set_rect_attribs(drawState);
 
     GrColor color = drawState->getColor();
-    if (GrColorIsOpaque(color)) {
+    if (kUseCoverage_CoverageAttribType == covAttribType && GrColorIsOpaque(color)) {
         drawState->setHint(GrDrawState::kVertexColorsAreOpaque_Hint, true);
     }
 
     int innerVertexNum = 4;
     int outerVertexNum = miterStroke ? 4 : 8;
     int totalVertexNum = (outerVertexNum + innerVertexNum) * 2;
 
     GrDrawTarget::AutoReleaseGeometry geo(target, totalVertexNum, 0);
     if (!geo.succeeded()) {
         GrPrintf("Failed to get space for vertices!\n");
@@ skipping 52 matching lines @@
         // inner one of the inner two
         set_inset_fan(fan2Pos, vsize, devInside,  -inset, -inset);
         // innermost
         set_inset_fan(fan3Pos, vsize, devInside,   SK_ScalarHalf,  SK_ScalarHalf);
     }
 
     // Make verts point to vertex color and then set all the color and coverage vertex attrs values.
     // The outermost rect has 0 coverage
     verts += sizeof(SkPoint);
     for (int i = 0; i < outerVertexNum; ++i) {
-        *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
-        *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = 0;
+        if (kUseCoverage_CoverageAttribType == covAttribType) {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
+            *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = 0;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = 0;
+        }
     }
 
     // scale is the coverage for the the inner two rects.
     int scale;
     if (inset < SK_ScalarHalf) {
         scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
         SkASSERT(scale >= 0 && scale <= 255);
     } else {
         scale = 0xff;
     }
 
     verts += outerVertexNum * vsize;
-    GrColor innerCoverage = GrColorPackRGBA(scale, scale, scale, scale);
+    GrColor innerCoverage;
+    if (kUseCoverage_CoverageAttribType == covAttribType) {
+        innerCoverage = GrColorPackRGBA(scale, scale, scale, scale);
+    } else {
+        innerCoverage = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
+    }
+
     for (int i = 0; i < outerVertexNum + innerVertexNum; ++i) {
-        *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
-        *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = innerCoverage;
+        if (kUseCoverage_CoverageAttribType == covAttribType) {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
+            *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = innerCoverage;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = innerCoverage;
+        }
     }
 
     // The innermost rect has 0 coverage
     verts += (outerVertexNum + innerVertexNum) * vsize;
     for (int i = 0; i < innerVertexNum; ++i) {
-        *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
-        *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = 0;
+        if (kUseCoverage_CoverageAttribType == covAttribType) {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = color;
+            *reinterpret_cast<GrColor*>(verts + i * vsize + sizeof(GrColor)) = 0;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vsize) = 0;
+        }
     }
 
     target->setIndexSourceToBuffer(indexBuffer);
     target->drawIndexed(kTriangles_GrPrimitiveType, 0, 0,
                         totalVertexNum, aaStrokeRectIndexCount(miterStroke));
 }
 
 void GrAARectRenderer::fillAANestedRects(GrGpu* gpu,
                                          GrDrawTarget* target,
                                          const SkRect rects[2],
                                          const SkMatrix& combinedMatrix) {
     SkASSERT(combinedMatrix.rectStaysRect());
     SkASSERT(!rects[1].isEmpty());
 
     SkRect devOutside, devOutsideAssist, devInside;
     combinedMatrix.mapRect(&devOutside, rects[0]);
     // can't call mapRect for devInside since it calls sort
     combinedMatrix.mapPoints((SkPoint*)&devInside, (const SkPoint*)&rects[1], 2);
 
     if (devInside.isEmpty()) {
         this->fillAARect(gpu, target, devOutside, SkMatrix::I(), devOutside);
         return;
     }
 
     this->geometryStrokeAARect(gpu, target, devOutside, devOutsideAssist, devInside, true);
 }