impl 4f version for tricolor shader

Bug: skia:
Change-Id: I43f456aa115ce71a5d1acd9bc94984248a88319a
Reviewed-on: https://skia-review.googlesource.com/15540
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index c3a5b3f8be..707c3a6a1c 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1696,6 +1696,7 @@ public:
         TriColorShaderContext(const SkTriColorShader& shader, const ContextRec&);
         ~TriColorShaderContext() override;
         void shadeSpan(int x, int y, SkPMColor dstC[], int count) override;
+        void shadeSpan4f(int x, int y, SkPM4f dstC[], int count) override;
 
     private:
         bool setup(const SkPoint pts[], const SkColor colors[], int, int, int);
@@ -1704,6 +1705,7 @@ public:
         SkPMColor   fColors[3];
         bool fSetup;
 
+        SkPM4f  fC0, fC10, fC20, fDC;
         typedef SkShader::Context INHERITED;
     };
 
@@ -1765,6 +1767,22 @@ bool SkTriColorShader::TriColorShaderContext::setup(const SkPoint pts[], const S
     }
     // TODO replace INV(m) * INV(ctm) with INV(ctm * m)
     fDstToUnit.setConcat(im, ctmInv);
+
+    fC0 = SkPM4f::FromPMColor(fColors[0]);
+
+    Sk4f alpha(this->getPaintAlpha() * (1.0f / 255)),
+         c0 = fC0.to4f() * alpha,
+         c1 = SkPM4f::FromPMColor(fColors[1]).to4f() * alpha,
+         c2 = SkPM4f::FromPMColor(fColors[2]).to4f() * alpha,
+         dx(fDstToUnit.getScaleX()),
+         dy(fDstToUnit.getSkewY());
+
+    Sk4f c10 = c1 - c0,
+         c20 = c2 - c0;
+
+    fDC  = SkPM4f::From4f(dx * c10 + dy * c20);
+    fC10 = SkPM4f::From4f(c10);
+    fC20 = SkPM4f::From4f(c20);
     return true;
 }
 
@@ -1831,6 +1849,30 @@ void SkTriColorShader::TriColorShaderContext::shadeSpan(int x, int y, SkPMColor
     }
 }
 
+void SkTriColorShader::TriColorShaderContext::shadeSpan4f(int x, int y, SkPM4f dstC[], int count) {
+    SkTriColorShader* parent = static_cast<SkTriColorShader*>(const_cast<SkShader*>(&fShader));
+    TriColorShaderData* set = parent->takeSetupData();
+    if (set) {
+        fSetup = setup(set->pts, set->colors, set->state->f0, set->state->f1, set->state->f2);
+    }
+
+    if (!fSetup) {
+        // Invalid matrices. Not checked before so no need to assert.
+        return;
+    }
+
+    SkPoint src;
+    fDstToUnit.mapXY(SkIntToScalar(x) + 0.5, SkIntToScalar(y) + 0.5, &src);
+
+    Sk4f c  = fC0.to4f() + src.fX * fC10.to4f() + src.fY * fC20.to4f(),
+         dc = fDC.to4f();
+
+    for (int i = 0; i < count; i++) {
+        c.store(dstC[i].fVec);
+        c += dc;
+    }
+}
+
 #ifndef SK_IGNORE_TO_STRING
 void SkTriColorShader::toString(SkString* str) const {
     str->append("SkTriColorShader: (");