Revert "Revert "Revert "eliminated GrGLSLExpr"""

This reverts commit 796001c82eca5651bc6a221204f6186918781daf.

Reason for revert: looks to be causing problems in Chrome (https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_Trusty__dbg_/1553/layout-test-results/results.html)

Original change's description:
> Revert "Revert "eliminated GrGLSLExpr""
> 
> This reverts commit 5e550ab57e0204bfadd2cb69c47d2a85e38d6a4c.
> 
> Bug: skia:
> Change-Id: I4705e47dbd209aa8f43db3d28c856bd3aa9e49ab
> Reviewed-on: https://skia-review.googlesource.com/15187
> Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
> Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
> 

TBR=ethannicholas@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I6455a4f16b2dc0d6d1265541f7117e0cfb8dd91c
Reviewed-on: https://skia-review.googlesource.com/15309
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

1 files changed, 27 insertions, 29 deletions

diff --git a/src/gpu/glsl/GrGLSLProgramBuilder.cpp b/src/gpu/glsl/GrGLSLProgramBuilder.cpp
index 3094f194ec..12e7ca2c1d 100644
--- a/src/gpu/glsl/GrGLSLProgramBuilder.cpp
+++ b/src/gpu/glsl/GrGLSLProgramBuilder.cpp
@@ -53,24 +53,24 @@ void GrGLSLProgramBuilder::addFeature(GrShaderFlags shaders,
     }
 }
 
-bool GrGLSLProgramBuilder::emitAndInstallProcs() {
+bool GrGLSLProgramBuilder::emitAndInstallProcs(GrGLSLExpr4* inputColor,
+                                               GrGLSLExpr4* inputCoverage) {
     // First we loop over all of the installed processors and collect coord transforms.  These will
     // be sent to the GrGLSLPrimitiveProcessor in its emitCode function
     const GrPrimitiveProcessor& primProc = this->primitiveProcessor();
 
-    SkString inputColor;
-    SkString inputCoverage;
-    this->emitAndInstallPrimProc(primProc, &inputColor, &inputCoverage);
-    this->emitAndInstallFragProcs(&inputColor, &inputCoverage);
-    this->emitAndInstallXferProc(inputColor, inputCoverage);
+    this->emitAndInstallPrimProc(primProc, inputColor, inputCoverage);
+
+    this->emitAndInstallFragProcs(inputColor, inputCoverage);
+    this->emitAndInstallXferProc(*inputColor, *inputCoverage);
     this->emitFSOutputSwizzle(this->pipeline().getXferProcessor().hasSecondaryOutput());
 
     return this->checkSamplerCounts() && this->checkImageStorageCounts();
 }
 
 void GrGLSLProgramBuilder::emitAndInstallPrimProc(const GrPrimitiveProcessor& proc,
-                                                  SkString* outputColor,
-                                                  SkString* outputCoverage) {
+                                                  GrGLSLExpr4* outputColor,
+                                                  GrGLSLExpr4* outputCoverage) {
     // Program builders have a bit of state we need to clear with each effect
     AutoStageAdvance adv(this);
     this->nameExpression(outputColor, "outputColor");
@@ -139,16 +139,16 @@ void GrGLSLProgramBuilder::emitAndInstallPrimProc(const GrPrimitiveProcessor& pr
     fFS.codeAppend("}");
 }
 
-void GrGLSLProgramBuilder::emitAndInstallFragProcs(SkString* color, SkString* coverage) {
+void GrGLSLProgramBuilder::emitAndInstallFragProcs(GrGLSLExpr4* color, GrGLSLExpr4* coverage) {
     int transformedCoordVarsIdx = 0;
-    SkString** inOut = &color;
+    GrGLSLExpr4** inOut = &color;
     for (int i = 0; i < this->pipeline().numFragmentProcessors(); ++i) {
         if (i == this->pipeline().numColorFragmentProcessors()) {
             inOut = &coverage;
         }
-        SkString output;
+        GrGLSLExpr4 output;
         const GrFragmentProcessor& fp = this->pipeline().getFragmentProcessor(i);
-        output = this->emitAndInstallFragProc(fp, i, transformedCoordVarsIdx, **inOut, output);
+        this->emitAndInstallFragProc(fp, i, transformedCoordVarsIdx, **inOut, &output);
         GrFragmentProcessor::Iter iter(&fp);
         while (const GrFragmentProcessor* fp = iter.next()) {
             transformedCoordVarsIdx += fp->numCoordTransforms();
@@ -158,16 +158,15 @@ void GrGLSLProgramBuilder::emitAndInstallFragProcs(SkString* color, SkString* co
 }
 
 // TODO Processors cannot output zeros because an empty string is all 1s
-// the fix is to allow effects to take the SkString directly
-SkString GrGLSLProgramBuilder::emitAndInstallFragProc(const GrFragmentProcessor& fp,
-                                                      int index,
-                                                      int transformedCoordVarsIdx,
-                                                      const SkString& input,
-                                                      SkString output) {
-    SkASSERT(input.size());
+// the fix is to allow effects to take the GrGLSLExpr4 directly
+void GrGLSLProgramBuilder::emitAndInstallFragProc(const GrFragmentProcessor& fp,
+                                                  int index,
+                                                  int transformedCoordVarsIdx,
+                                                  const GrGLSLExpr4& input,
+                                                  GrGLSLExpr4* output) {
     // Program builders have a bit of state we need to clear with each effect
     AutoStageAdvance adv(this);
-    this->nameExpression(&output, "output");
+    this->nameExpression(output, "output");
 
     // Enclose custom code in a block to avoid namespace conflicts
     SkString openBrace;
@@ -194,8 +193,8 @@ SkString GrGLSLProgramBuilder::emitAndInstallFragProc(const GrFragmentProcessor&
                                            this->uniformHandler(),
                                            this->shaderCaps(),
                                            fp,
-                                           output.c_str(),
-                                           input.c_str(),
+                                           output->c_str(),
+                                           input.isOnes() ? nullptr : input.c_str(),
                                            coords,
                                            textureSamplers,
                                            bufferSamplers,
@@ -210,11 +209,10 @@ SkString GrGLSLProgramBuilder::emitAndInstallFragProc(const GrFragmentProcessor&
     fFragmentProcessors.push_back(fragProc);
 
     fFS.codeAppend("}");
-    return output;
 }
 
-void GrGLSLProgramBuilder::emitAndInstallXferProc(const SkString& colorIn,
-                                                  const SkString& coverageIn) {
+void GrGLSLProgramBuilder::emitAndInstallXferProc(const GrGLSLExpr4& colorIn,
+                                                  const GrGLSLExpr4& coverageIn) {
     // Program builders have a bit of state we need to clear with each effect
     AutoStageAdvance adv(this);
 
@@ -251,8 +249,8 @@ void GrGLSLProgramBuilder::emitAndInstallXferProc(const SkString& colorIn,
                                        this->uniformHandler(),
                                        this->shaderCaps(),
                                        xp,
-                                       colorIn.size() ? colorIn.c_str() : "vec4(1)",
-                                       coverageIn.size() ? coverageIn.c_str() : "vec4(1)",
+                                       colorIn.c_str(),
+                                       coverageIn.c_str(),
                                        fFS.getPrimaryColorOutputName(),
                                        fFS.getSecondaryColorOutputName(),
                                        dstTextureSamplerHandle,
@@ -447,12 +445,12 @@ void GrGLSLProgramBuilder::nameVariable(SkString* out, char prefix, const char*
     }
 }
 
-void GrGLSLProgramBuilder::nameExpression(SkString* output, const char* baseName) {
+void GrGLSLProgramBuilder::nameExpression(GrGLSLExpr4* output, const char* baseName) {
     // create var to hold stage result.  If we already have a valid output name, just use that
     // otherwise create a new mangled one.  This name is only valid if we are reordering stages
     // and have to tell stage exactly where to put its output.
     SkString outName;
-    if (output->size()) {
+    if (output->isValid()) {
         outName = output->c_str();
     } else {
         this->nameVariable(&outName, '\0', baseName);