commit 0426947243e1d6b470830c4d3b1c5704ed1f23e1
author Michael Ludwig <michaelludwig@google.com> Fri Jun 19 10:47:30 2020 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Jun 19 20:26:05 2020 +0000
tree f6e4a42fc33b2cbada4de7e96a2b350527efb3ed
parent a581a8b80087033f140f95017d84b6c02962794e

Centralize geometry processor vertex shader transform code

GrGLSLGeometryProcessors no longer have to call emitTransforms() in
their onEmitCode() function. Instead, the GpArgs struct allows them to
set a GrShaderVar that holds the computed or explicitly provided local
coordinates in the vertex shader.

The base GrGLSLGeometryProcessor now automatically uses that to collect
all of the transforms that can then be lifted out of FPs to the vertex
shader, and base their computation on the GP provided local coordinate.

As part of this, there is no more built-in magic concatenation of a
local matrix / inverse view matrix to these coordinate transforms. GP
implementations that relied on this now manage their own uniform for this
matrix and compute the local coordinate before assigning to GpArgs.

The base GrGLSLGeometryProcessor is updated to provide helpers for this
pattern.

Bug: skia:10396
Change-Id: I56afb3fff4b806f6015ab13626ac1afde9ef5c2b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/297027
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

src/gpu/GrDefaultGeoProcFactory.cpp

diff --git a/src/gpu/GrDefaultGeoProcFactory.cpp b/src/gpu/GrDefaultGeoProcFactory.cpp
index 4f93238..94ba184 100644
--- a/src/gpu/GrDefaultGeoProcFactory.cpp
+++ b/src/gpu/GrDefaultGeoProcFactory.cpp
@@ -57,6 +57,7 @@
     public:
         GLSLProcessor()
             : fViewMatrix(SkMatrix::InvalidMatrix())
+            , fLocalMatrix(SkMatrix::InvalidMatrix())
             , fColor(SK_PMColor4fILLEGAL)
             , fCoverage(0xff) {}
 
@@ -111,14 +112,14 @@
                                       &fViewMatrixUniform);
 
             // emit transforms using either explicit local coords or positions
-            const auto& coordsAttr = gp.fInLocalCoords.isInitialized() ? gp.fInLocalCoords
-                                                                       : gp.fInPosition;
-            this->emitTransforms(vertBuilder,
-                                 varyingHandler,
-                                 uniformHandler,
-                                 coordsAttr.asShaderVar(),
-                                 gp.localMatrix(),
-                                 args.fFPCoordTransformHandler);
+            if (gp.fInLocalCoords.isInitialized()) {
+                SkASSERT(gp.localMatrix().isIdentity());
+                gpArgs->fLocalCoordVar = gp.fInLocalCoords.asShaderVar();
+            } else if (gp.fLocalCoordsWillBeRead) {
+                this->writeLocalCoord(vertBuilder, uniformHandler, gpArgs,
+                                      gp.fInPosition.asShaderVar(), gp.localMatrix(),
+                                      &fLocalMatrixUniform);
+            }
 
             // Setup coverage as pass through
             if (gp.hasVertexCoverage() && !tweakAlpha) {
@@ -144,8 +145,12 @@
             const DefaultGeoProc& def = gp.cast<DefaultGeoProc>();
             uint32_t key = def.fFlags;
             key |= (def.coverage() == 0xff) ? 0x80 : 0;
-            key |= (def.localCoordsWillBeRead() && def.localMatrix().hasPerspective()) ? 0x100 : 0;
-            key |= ComputePosKey(def.viewMatrix()) << 20;
+            key |= def.localCoordsWillBeRead() ? 0x100 : 0;
+
+            bool usesLocalMatrix = def.localCoordsWillBeRead() &&
+                                   !def.fInLocalCoords.isInitialized();
+            key = AddMatrixKeys(key, def.viewMatrix(),
+                                usesLocalMatrix ? def.localMatrix() : SkMatrix::I());
             b->add32(key);
         }
 
@@ -154,12 +159,9 @@
                      const CoordTransformRange& transformRange) override {
             const DefaultGeoProc& dgp = gp.cast<DefaultGeoProc>();
 
-            if (!dgp.viewMatrix().isIdentity() &&
-                !SkMatrixPriv::CheapEqual(fViewMatrix, dgp.viewMatrix()))
-            {
-                fViewMatrix = dgp.viewMatrix();
-                pdman.setSkMatrix(fViewMatrixUniform, fViewMatrix);
-            }
+            this->setTransform(pdman, fViewMatrixUniform, dgp.viewMatrix(), &fViewMatrix);
+            this->setTransform(pdman, fLocalMatrixUniform, dgp.localMatrix(), &fLocalMatrix);
+            this->setTransformDataHelper(pdman, transformRange);
 
             if (!dgp.hasVertexColor() && dgp.color() != fColor) {
                 pdman.set4fv(fColorUniform, 1, dgp.color().vec());
@@ -170,14 +172,15 @@
                 pdman.set1f(fCoverageUniform, GrNormalizeByteToFloat(dgp.coverage()));
                 fCoverage = dgp.coverage();
             }
-            this->setTransformDataHelper(dgp.fLocalMatrix, pdman, transformRange);
         }
 
     private:
         SkMatrix fViewMatrix;
+        SkMatrix fLocalMatrix;
         SkPMColor4f fColor;
         uint8_t fCoverage;
         UniformHandle fViewMatrixUniform;
+        UniformHandle fLocalMatrixUniform;
         UniformHandle fColorUniform;
         UniformHandle fCoverageUniform;