commit e38beddbbf8a06c91bf704f5225dfe1e3cce2e6e
author Brian Osman <brianosman@google.com> Mon Dec 21 11:51:54 2020 -0500
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue Dec 22 14:21:32 2020 +0000
tree 442ed23471da9645ffcc1dd23b6cf13ed0973af8
parent f02df4db61185930f3d9ffa8e9e85f18c40ea146

Remove SkSL InverseW setting

This was added to workaround a bug in D3D (w/SPIRV-cross). It's now
handled correctly in SPIRV-cross itself, so this is unused.

Change-Id: Ic411ee2219cf370bcebff18ae18689d16da90866
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/344966
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

src/sksl/SkSLSPIRVCodeGenerator.cpp

diff --git a/src/sksl/SkSLSPIRVCodeGenerator.cpp b/src/sksl/SkSLSPIRVCodeGenerator.cpp
index e2805a3..2d57341 100644
--- a/src/sksl/SkSLSPIRVCodeGenerator.cpp
+++ b/src/sksl/SkSLSPIRVCodeGenerator.cpp
@@ -1869,7 +1869,7 @@
     this->writeInstruction(SpvOpLoad, this->getType(ref.variable()->type()), result, var, out);
     this->writePrecisionModifier(ref.variable()->type(), result);
     if (ref.variable()->modifiers().fLayout.fBuiltin == SK_FRAGCOORD_BUILTIN &&
-        (fProgram.fSettings.fFlipY || fProgram.fSettings.fInverseW)) {
+        fProgram.fSettings.fFlipY) {
         // The x component never changes, so just grab it
         SpvId xId = this->nextId();
         this->writeInstruction(SpvOpCompositeExtract, this->getType(*fContext.fFloat_Type), xId,
@@ -1950,19 +1950,10 @@
         FloatLiteral zero(fContext, -1, 0.0);
         SpvId zeroId = writeFloatLiteral(zero);
 
-        // Calculate the w component which may need to be inverted
+        // Calculate the w component
         SpvId rawWId = this->nextId();
         this->writeInstruction(SpvOpCompositeExtract, this->getType(*fContext.fFloat_Type), rawWId,
                                result, 3, out);
-        SpvId invWId = 0;
-        if (fProgram.fSettings.fInverseW) {
-            // We need to invert w
-            FloatLiteral one(fContext, -1, 1.0);
-            SpvId oneId = writeFloatLiteral(one);
-            invWId = this->nextId();
-            this->writeInstruction(SpvOpFDiv, this->getType(*fContext.fFloat_Type), invWId, oneId,
-                                   rawWId, out);
-        }
 
         // Fill in the new fragcoord with the components from above
         SpvId adjusted = this->nextId();
@@ -1976,11 +1967,7 @@
             this->writeWord(rawYId, out);
         }
         this->writeWord(zeroId, out);
-        if (fProgram.fSettings.fInverseW) {
-            this->writeWord(invWId, out);
-        } else {
-            this->writeWord(rawWId, out);
-        }
+        this->writeWord(rawWId, out);
 
         return adjusted;
     }