move colorshader into its own .cpp, add color4f variant

Implemented as a different subclass for SkColorShader (which is also private) partly to make the CL clearer/simpler, and partly for flatten/unflatten compatibility. Later I'm sure we could combine these if that proves useful.

Lots of TODOs at the moment, but still valuable to get reviewed.

Note: this ignores the question (for the moment) about how to interpret SkColor in the larger world. That needs to happen, but this CL is more focused on what *else* to do besides handle the old-style input (and old-style pipeline).

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1934313002

Review-Url: https://codereview.chromium.org/1934313002

1 files changed, 39 insertions, 0 deletions

diff --git a/gm/color4f.cpp b/gm/color4f.cpp
index 2585ad87c1..829434c248 100644
--- a/gm/color4f.cpp
+++ b/gm/color4f.cpp
@@ -84,3 +84,42 @@ DEF_SIMPLE_GM(color4f, canvas, 1024, 260) {
         canvas->translate(0, 120);
     }
 }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+#include "SkColorSpace.h"
+
+DEF_SIMPLE_GM(color4shader, canvas, 1024, 260) {
+    canvas->translate(10, 10);
+
+    SkMatrix44 mat(SkMatrix44::kUninitialized_Constructor);
+    // red -> blue, green -> red, blue -> green
+    mat.set3x3(0, 1, 0, 0, 0, 1, 1, 0, 0);
+
+    const SkColor4f colors[] {
+        { 1, 1, 0, 0 },
+        { 1, 0, 1, 0 },
+        { 1, 0, 0, 1 },
+        { 1, 0.5, 0.5, 0.5 },
+    };
+
+    SkPaint paint;
+    SkRect r = SkRect::MakeWH(100, 100);
+
+    for (const auto& c4 : colors) {
+        sk_sp<SkShader> shaders[] {
+            SkShader::MakeColorShader(c4, nullptr),
+            SkShader::MakeColorShader(c4, SkColorSpace::NewNamed(SkColorSpace::kSRGB_Named)),
+            SkShader::MakeColorShader(c4, SkColorSpace::NewRGB(SkColorSpace::SkGammas(1, 1, 1),
+                                                               mat)),
+        };
+
+        canvas->save();
+        for (const auto& s : shaders) {
+            paint.setShader(s);
+            canvas->drawRect(r, paint);
+            canvas->translate(r.width() * 6 / 5, 0);
+        }
+        canvas->restore();
+        canvas->translate(0, r.height() * 6 / 5);
+    }
+}