Implement NVPR on GLES

src/gpu/gl/GrGpuGL.cpp

Index: src/gpu/gl/GrGpuGL.cpp
diff --git a/src/gpu/gl/GrGpuGL.cpp b/src/gpu/gl/GrGpuGL.cpp
index 52caf9d3ea31564eb7061f287b04cdc37234df9a..b45f443f9e96ea30c9621dd68e8162a73978ec01 100644
--- a/src/gpu/gl/GrGpuGL.cpp
+++ b/src/gpu/gl/GrGpuGL.cpp
@@ -136,8 +136,15 @@ GrGpuGL::GrGpuGL(const GrGLContext& ctx, GrContext* context)
     SkASSERT(ctx.isInitialized());
     fCaps.reset(SkRef(ctx.caps()));
 
+    if (this->glCaps().pathRenderingSupport()) {
+        fPathRendering.reset(GrGLPathRendering::Create(glInterface()));
+    }
+
     fHWBoundTextureUniqueIDs.reset(this->glCaps().maxFragmentTextureUnits());
-    fHWPathTexGenSettings.reset(this->glCaps().maxFixedFunctionTextureCoords());
+    if (this->glCaps().pathRenderingSupport() &&
+        !this->pathRendering()->caps().fragmentInputGenSupport) {

[bsalomon, 2014/08/07 21:02:52]

Maybe we should move the hw path tex gen settings stuff into GrGLPathRendering
and move the cap bits that specify particulars of the nvpr extension in play
there as well.. I'm not crazy about having this public fragmentinputGenSupport
on caps and it feels like GrGLPathRendering would better encapsulate path
rendering.

[Chris Dalton, 2014/08/07 23:02:55]

The original idea for GrGLPathRendering was to mirror the NVPR api exactly,
which does require a check for fragmentinputGenSupport (since it is impossible
to provide a backup implementation).

But we could alternatively invent our own non-nvpr method on GrGLPathRendering
that uses ProgramPathFragmentInputGen and falls back on PathTexGen. It would be
tricky though, since GrGLPathRendering would then have to somehow influence the
shader builders and coord transforms.

+        fHWPathTexGenSettings.reset(this->glCaps().maxFixedFunctionTextureCoords());
+    }
 
     GrGLClearErr(fGLContext.interface());
     if (gPrintStartupSpew) {
@@ -164,10 +171,6 @@ GrGpuGL::GrGpuGL(const GrGLContext& ctx, GrContext* context)
 
     fLastSuccessfulStencilFmtIdx = 0;
     fHWProgramID = 0;
-
-    if (this->glCaps().pathRenderingSupport()) {
-        fPathRendering.reset(GrGLPathRendering::Create(glInterface()));
-    }
 }
 
 GrGpuGL::~GrGpuGL() {
@@ -330,14 +333,19 @@ void GrGpuGL::onResetContext(uint32_t resetBits) {
         if (this->caps()->pathRenderingSupport()) {
             fHWProjectionMatrixState.invalidate();
             // we don't use the model view matrix.

[bsalomon, 2014/08/07 21:02:52]

Again, I think we should move this state tracking stuff to the PR class.

-            GL_CALL(MatrixLoadIdentity(GR_GL_MODELVIEW));
+            GrGLenum matrixMode =
+                this->glStandard() == kGLES_GrGLStandard ? GR_GL_PATH_MODELVIEW : GR_GL_MODELVIEW;
+
+            GL_CALL(MatrixLoadIdentity(matrixMode));
 
-            for (int i = 0; i < this->glCaps().maxFixedFunctionTextureCoords(); ++i) {
-                fPathRendering->pathTexGen(GR_GL_TEXTURE0 + i, GR_GL_NONE, 0, NULL);
-                fHWPathTexGenSettings[i].fMode = GR_GL_NONE;
-                fHWPathTexGenSettings[i].fNumComponents = 0;
+            if (!this->pathRendering()->caps().fragmentInputGenSupport) {
+                for (int i = 0; i < this->glCaps().maxFixedFunctionTextureCoords(); ++i) {
+                    fPathRendering->pathTexGen(GR_GL_TEXTURE0 + i, GR_GL_NONE, 0, NULL);
+                    fHWPathTexGenSettings[i].fMode = GR_GL_NONE;
+                    fHWPathTexGenSettings[i].fNumComponents = 0;
+                }
+                fHWActivePathTexGenSets = 0;
             }
-            fHWActivePathTexGenSets = 0;
         }
         fHWPathStencilSettings.invalidate();
     }
@@ -1894,7 +1902,6 @@ void GrGpuGL::onGpuDrawPath(const GrPath* path, SkPath::FillType fill) {
     GrGLuint id = static_cast<const GrGLPath*>(path)->pathID();
     SkASSERT(NULL != this->drawState()->getRenderTarget());
     SkASSERT(NULL != this->drawState()->getRenderTarget()->getStencilBuffer());
-    SkASSERT(!fCurrentProgram->hasVertexShader());
 
     flushPathStencilSettings(fill);
     const SkStrokeRec& stroke = path->getStroke();
@@ -1950,7 +1957,6 @@ void GrGpuGL::onGpuDrawPaths(const GrPathRange* pathRange,
     SkASSERT(this->caps()->pathRenderingSupport());

[bsalomon, 2014/08/07 21:02:52]

Move whole impl to path rendering class?

     SkASSERT(NULL != this->drawState()->getRenderTarget());
     SkASSERT(NULL != this->drawState()->getRenderTarget()->getStencilBuffer());
-    SkASSERT(!fCurrentProgram->hasVertexShader());
 
     GrGLuint baseID = static_cast<const GrGLPathRange*>(pathRange)->basePathID();
 
@@ -2386,7 +2392,11 @@ void GrGpuGL::setProjectionMatrix(const SkMatrix& matrix,
 
     GrGLfloat glMatrix[4 * 4];
     fHWProjectionMatrixState.getRTAdjustedGLMatrix<4>(glMatrix);
-    GL_CALL(MatrixLoadf(GR_GL_PROJECTION, glMatrix));
+
+    GrGLenum matrixMode =

[bsalomon, 2014/08/07 21:02:52]

Move to PR class?

+        this->glStandard() == kGLES_GrGLStandard ? GR_GL_PATH_PROJECTION : GR_GL_PROJECTION;
+
+    GL_CALL(MatrixLoadf(matrixMode, glMatrix));
 }
 
 void GrGpuGL::enablePathTexGen(int unitIdx,