Disable GL_MULTISAMPLE when it's not being used

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLGpu.h"
 #include "GrGLStencilBuffer.h"
@@ skipping 1369 matching lines @@
                 fHWScissorSettings.fEnabled = kYes_TriState;
             }
             return;
         }
     }
 
     // See fall through note above
     this->disableScissor();
 }
 
-bool GrGLGpu::flushGLState(const DrawArgs& args, bool isLineDraw) {
+bool GrGLGpu::flushGLState(const DrawArgs& args) {
     GrXferProcessor::BlendInfo blendInfo;
     const GrPipeline& pipeline = *args.fPipeline;
     args.fPipeline->getXferProcessor()->getBlendInfo(&blendInfo);
 
     this->flushDither(pipeline.isDitherState());
     this->flushColorWrite(blendInfo.fWriteColor);
     this->flushDrawFace(pipeline.getDrawFace());
 
     fCurrentProgram.reset(fProgramCache->getProgram(args));
     if (NULL == fCurrentProgram.get()) {
@@ skipping 11 matching lines @@
 
     if (blendInfo.fWriteColor) {
         this->flushBlend(blendInfo);
     }
 
     fCurrentProgram->setData(*args.fPrimitiveProcessor, pipeline, *args.fBatchTracker);
 
     GrGLRenderTarget* glRT = static_cast<GrGLRenderTarget*>(pipeline.getRenderTarget());
     this->flushStencil(pipeline.getStencil());
     this->flushScissor(pipeline.getScissorState(), glRT->getViewport(), glRT->origin());
-    this->flushHWAAState(glRT, pipeline.isHWAntialiasState(), isLineDraw);
+    this->flushHWAAState(glRT, pipeline.isHWAntialiasState());
 
     // This must come after textures are flushed because a texture may need
     // to be msaa-resolved (which will modify bound FBO state).
     this->flushRenderTarget(glRT, NULL);
 
     return true;
 }
 
 void GrGLGpu::setupGeometry(const GrPrimitiveProcessor& primProc,
                             const GrDrawTarget::DrawInfo& info,
@@ skipping 433 matching lines @@
                 if(wndProcID == procID) {
                     SwapBuffers(GetDC(hwnd));
                 }
                 hwnd = GetNextWindow(hwnd, GW_HWNDNEXT);
             }
          }
     #endif
 #endif
 
 void GrGLGpu::onDraw(const DrawArgs& args, const GrDrawTarget::DrawInfo& info) {
-    if (!this->flushGLState(args, GrIsPrimTypeLines(info.primitiveType()))) {
+    if (!this->flushGLState(args)) {
         return;
     }
 
     size_t indexOffsetInBytes = 0;
     this->setupGeometry(*args.fPrimitiveProcessor, info, &indexOffsetInBytes);
 
     SkASSERT((size_t)info.primitiveType() < SK_ARRAY_COUNT(gPrimitiveType2GLMode));
 
     if (info.isIndexed()) {
         GrGLvoid* indices =
@@ skipping 24 matching lines @@
 }
 
 void GrGLGpu::onStencilPath(const GrPath* path, const StencilPathState& state) {
     this->flushColorWrite(false);
     this->flushDrawFace(GrPipelineBuilder::kBoth_DrawFace);
 
     GrGLRenderTarget* rt = static_cast<GrGLRenderTarget*>(state.fRenderTarget);
     SkISize size = SkISize::Make(rt->width(), rt->height());
     this->glPathRendering()->setProjectionMatrix(*state.fViewMatrix, size, rt->origin());
     this->flushScissor(*state.fScissor, rt->getViewport(), rt->origin());
-    this->flushHWAAState(rt, state.fUseHWAA, false);
+    this->flushHWAAState(rt, state.fUseHWAA);
     this->flushRenderTarget(rt, NULL);
 
     fPathRendering->stencilPath(path, *state.fStencil);
 }
 
 void GrGLGpu::onDrawPath(const DrawArgs& args, const GrPath* path,
                          const GrStencilSettings& stencil) {
-    if (!this->flushGLState(args, false)) {
+    if (!this->flushGLState(args)) {
         return;
     }
     fPathRendering->drawPath(path, stencil);
 }
 
 void GrGLGpu::onDrawPaths(const DrawArgs& args,
                           const GrPathRange* pathRange,
                           const void* indices,
                           GrDrawTarget::PathIndexType indexType,
                           const float transformValues[],
                           GrDrawTarget::PathTransformType transformType,
                            int count,
                            const GrStencilSettings& stencil) {
-    if (!this->flushGLState(args, false)) {
+    if (!this->flushGLState(args)) {
         return;
     }
     fPathRendering->drawPaths(pathRange, indices, indexType, transformValues,
                               transformType, count, stencil);
 }
 
 void GrGLGpu::onResolveRenderTarget(GrRenderTarget* target) {
     GrGLRenderTarget* rt = static_cast<GrGLRenderTarget*>(target);
     if (rt->needsResolve()) {
         // Some extensions automatically resolves the texture when it is read.
@@ skipping 114 matching lines @@
                 set_gl_stencil(this->glInterface(),
                                stencilSettings,
                                GR_GL_FRONT_AND_BACK,
                                GrStencilSettings::kFront_Face);
             }
         }
         fHWStencilSettings = stencilSettings;
     }
 }
 
-void GrGLGpu::flushHWAAState(GrRenderTarget* rt, bool useHWAA, bool isLineDraw) {
-// At least some ATI linux drivers will render GL_LINES incorrectly when MSAA state is enabled but
-// the target is not multisampled. Single pixel wide lines are rendered thicker than 1 pixel wide.
-#if 0
-    // Replace RT_HAS_MSAA with this definition once this driver bug is no longer a relevant concern
-    #define RT_HAS_MSAA rt->isMultisampled()
-#else
-    #define RT_HAS_MSAA (rt->isMultisampled() || isLineDraw)
-#endif
+void GrGLGpu::flushHWAAState(GrRenderTarget* rt, bool useHWAA) {
+    SkASSERT(!useHWAA || rt->isMultisampled());
 
     if (kGL_GrGLStandard == this->glStandard()) {
-        if (RT_HAS_MSAA) {
-            if (useHWAA) {
-                if (kYes_TriState != fMSAAEnabled) {
-                    GL_CALL(Enable(GR_GL_MULTISAMPLE));
-                    fMSAAEnabled = kYes_TriState;
-                }
-            } else {
-                if (kNo_TriState != fMSAAEnabled) {
-                    GL_CALL(Disable(GR_GL_MULTISAMPLE));
-                    fMSAAEnabled = kNo_TriState;
-                }
+        if (useHWAA) {
+            if (kYes_TriState != fMSAAEnabled) {
+                GL_CALL(Enable(GR_GL_MULTISAMPLE));
+                fMSAAEnabled = kYes_TriState;
+            }
+        } else {
+            if (kNo_TriState != fMSAAEnabled) {
+                GL_CALL(Disable(GR_GL_MULTISAMPLE));
+                fMSAAEnabled = kNo_TriState;
             }
         }
     }
 }
 
 void GrGLGpu::flushBlend(const GrXferProcessor::BlendInfo& blendInfo) {
     // Any optimization to disable blending should have already been applied and
     // tweaked the coeffs to (1, 0).
     
     GrBlendCoeff srcCoeff = blendInfo.fSrcBlend;
@@ skipping 695 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }