Sketch SkPMFloat

tests/PMFloatTest.cpp

+#include "SkPMFloat.h"
+#include "Test.h"
+
+DEF_TEST(SkPMFloat, r) {
+    SkPMColor c = SkPreMultiplyColor(0xFFCC9933);
+
+    SkPMFloat pmf;
+    pmf.set(c);
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(1.0f, pmf.a()));
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(0.8f, pmf.r()));
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(0.6f, pmf.g()));
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(0.2f, pmf.b()));
+
+    REPORTER_ASSERT(r, c == pmf.get());
+
+    SkPMFloat unclamped;
+    unclamped.setA(+2.0f);
+    unclamped.setR(+0.2f);
+    unclamped.setG(-0.2f);
+    unclamped.setB(-5.0f);
+
+    SkPMFloat clamped;
+    clamped.set(unclamped.clamped());
+
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(1.0f, clamped.a()));
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(0.2f, clamped.r()));
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(0.0f, clamped.g()));
+    REPORTER_ASSERT(r, SkScalarNearlyEqual(0.0f, clamped.b()));
+}