Revert "Make SkSL GLSL generator declare sk_FragColor inout when EXT fb fetch is used."

This reverts commit 7e1dd2017a59a748c6cb10160868780d2dffdbc0.

Reason for revert: breaking fp compilation

Original change's description:
> Make SkSL GLSL generator declare sk_FragColor inout when EXT fb fetch is used.
> 
> Change-Id: I5e6e3263bb49febc757cd63d5d6c1518f174322d
> Reviewed-on: https://skia-review.googlesource.com/118420
> Reviewed-by: Greg Daniel <egdaniel@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

TBR=egdaniel@google.com,bsalomon@google.com

Change-Id: I2aedfaff93150ba8cd1ed9fed22f3cfdd509695a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/118600
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

5 files changed, 2 insertions, 10 deletions

diff --git a/src/sksl/SkSLGLSLCodeGenerator.cpp b/src/sksl/SkSLGLSLCodeGenerator.cpp
index 43c1c95327..996714ec62 100644
--- a/src/sksl/SkSLGLSLCodeGenerator.cpp
+++ b/src/sksl/SkSLGLSLCodeGenerator.cpp
@@ -1270,11 +1270,7 @@ void GLSLCodeGenerator::writeProgramElement(const ProgramElement& e) {
                     this->writeLine();
                 } else if (builtin == SK_FRAGCOLOR_BUILTIN &&
                            fProgram.fSettings.fCaps->mustDeclareFragmentShaderOutput()) {
-                    if (fProgram.fSettings.fFragColorIsInOut) {
-                        this->write("inout ");
-                    } else {
-                        this->write("out ");
-                    }
+                    this->write("out ");
                     if (usesPrecisionModifiers()) {
                         this->write("mediump ");
                     }
diff --git a/src/sksl/SkSLIRGenerator.cpp b/src/sksl/SkSLIRGenerator.cpp
index ec3f6068fe..56d8e5e952 100644
--- a/src/sksl/SkSLIRGenerator.cpp
+++ b/src/sksl/SkSLIRGenerator.cpp
@@ -126,6 +126,7 @@ static void fill_caps(const SKSL_CAPS_CLASS& caps,
 #define CAP(name) capsMap->insert(std::make_pair(String(#name), \
                                   Program::Settings::Value(caps.name())));
     CAP(fbFetchSupport);
+    CAP(fbFetchNeedsCustomOutput);
     CAP(dropsTileOnZeroDivide);
     CAP(flatInterpolationSupport);
     CAP(noperspectiveInterpolationSupport);
diff --git a/src/sksl/SkSLMetalCodeGenerator.cpp b/src/sksl/SkSLMetalCodeGenerator.cpp
index 88ab7ad682..de6b1d0854 100644
--- a/src/sksl/SkSLMetalCodeGenerator.cpp
+++ b/src/sksl/SkSLMetalCodeGenerator.cpp
@@ -451,8 +451,6 @@ void MetalCodeGenerator::writeFunction(const FunctionDefinition& f) {
     }
     this->writeLine(") {");
 
-    SkASSERT(!fProgram.fSettings.fFragColorIsInOut);
-
     if ("main" == f.fDeclaration.fName) {
         switch (fProgram.fKind) {
             case Program::kFragment_Kind:
diff --git a/src/sksl/SkSLSPIRVCodeGenerator.cpp b/src/sksl/SkSLSPIRVCodeGenerator.cpp
index 84bc4d85c7..dadab91753 100644
--- a/src/sksl/SkSLSPIRVCodeGenerator.cpp
+++ b/src/sksl/SkSLSPIRVCodeGenerator.cpp
@@ -2545,7 +2545,6 @@ void SPIRVCodeGenerator::writeGlobalVars(Program::Kind kind, const VarDeclaratio
         }
         if (var->fModifiers.fLayout.fBuiltin == SK_FRAGCOLOR_BUILTIN &&
             kind != Program::kFragment_Kind) {
-            SkASSERT(!fProgram.fSettings.fFragColorIsInOut);
             continue;
         }
         if (!var->fReadCount && !var->fWriteCount &&
diff --git a/src/sksl/ir/SkSLProgram.h b/src/sksl/ir/SkSLProgram.h
index 03a94fa03f..cbb9dfe1a7 100644
--- a/src/sksl/ir/SkSLProgram.h
+++ b/src/sksl/ir/SkSLProgram.h
@@ -71,8 +71,6 @@ struct Program {
         // if false, sk_FragCoord is exactly the same as gl_FragCoord. If true, the y coordinate
         // must be flipped.
         bool fFlipY = false;
-        // If true the destination fragment color is read sk_FragColor. It must be declared inout.
-        bool fFragColorIsInOut = false;
         // if true, Setting objects (e.g. sk_Caps.fbFetchSupport) should be replaced with their
         // constant equivalents during compilation
         bool fReplaceSettings = true;