add SkShader::newWithColorFilter

gm/colorfilterimagefilter.cpp

Index: gm/colorfilterimagefilter.cpp
diff --git a/gm/colorfilterimagefilter.cpp b/gm/colorfilterimagefilter.cpp
index efcd9b336df1e880480009187e103e17a056dc06..711a7e48c337e9cdd5bbd89af8981f9bfc844737 100644
--- a/gm/colorfilterimagefilter.cpp
+++ b/gm/colorfilterimagefilter.cpp
@@ -18,34 +18,92 @@
 #define FILTER_HEIGHT   SkIntToScalar(30)
 #define MARGIN          SkIntToScalar(10)
 
+static SkColorFilter* cf_make_brightness(float brightness) {
+    SkScalar amount255 = SkScalarMul(brightness, SkIntToScalar(255));
+    SkScalar matrix[20] = {
+        1, 0, 0, 0, amount255,
+        0, 1, 0, 0, amount255,
+        0, 0, 1, 0, amount255,
+        0, 0, 0, 1, 0 };
+    return SkColorMatrixFilter::Create(matrix);
+}
+
+static SkColorFilter* cf_make_grayscale() {
+    SkScalar matrix[20];
+    memset(matrix, 0, 20 * sizeof(SkScalar));
+    matrix[0] = matrix[5] = matrix[10] = 0.2126f;
+    matrix[1] = matrix[6] = matrix[11] = 0.7152f;
+    matrix[2] = matrix[7] = matrix[12] = 0.0722f;
+    matrix[18] = 1.0f;
+    return SkColorMatrixFilter::Create(matrix);
+}
+
+static SkColorFilter* cf_make_colorize(SkColor color) {
+    return SkColorFilter::CreateModeFilter(color, SkXfermode::kSrc_Mode);
+}
+
+static const SkTDArray<SkColorFilter*>& sk_gm_get_colorfilters() {
+    static SkTDArray<SkColorFilter*> gColorFilters;
+    
+    if (gColorFilters.count() == 0) {
+        *gColorFilters.append() = cf_make_brightness(0.5f);
+        *gColorFilters.append() = cf_make_grayscale();
+        *gColorFilters.append() = cf_make_colorize(SK_ColorBLUE);
+    }
+    return gColorFilters;
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+#include "SkGradientShader.h"
+#include "SkImage.h"
+#include "Resources.h"
+
+static SkShader* sh_make_lineargradient0() {
+    const SkPoint pts[] = { { 0, 0 }, { 100, 100 } };
+    const SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, 3, SkShader::kRepeat_TileMode);
+}
+
+static SkShader* sh_make_lineargradient1() {
+    const SkPoint pts[] = { { 0, 0 }, { 100, 100 } };
+    const SkColor colors[] = { SK_ColorRED, 0x0000FF00, SK_ColorBLUE };
+    return SkGradientShader::CreateLinear(pts, colors, nullptr, 3, SkShader::kRepeat_TileMode);
+}
+
+static SkShader* sh_make_image() {
+    SkAutoTUnref<SkImage> image(GetResourceAsImage("mandrill_128.png"));
+    return image->newShader(SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode);
+}
+
+static const SkTDArray<SkShader*>& sk_gm_get_shaders() {
+    static SkTDArray<SkShader*> gShaders;
+    
+    if (gShaders.count() == 0) {
+        *gShaders.append() = sh_make_lineargradient0();
+        *gShaders.append() = sh_make_lineargradient1();
+        *gShaders.append() = sh_make_image();
+    }
+    return gShaders;
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
 static SkImageFilter* make_blur(float amount, SkImageFilter* input = nullptr) {
     return SkBlurImageFilter::Create(amount, amount, input);
 }
 
 static SkImageFilter* make_brightness(float amount, SkImageFilter* input = nullptr) {
-    SkScalar amount255 = SkScalarMul(amount, SkIntToScalar(255));
-    SkScalar matrix[20] = { 1, 0, 0, 0, amount255,
-                            0, 1, 0, 0, amount255,
-                            0, 0, 1, 0, amount255,
-                            0, 0, 0, 1, 0 };
-    SkAutoTUnref<SkColorFilter> filter(SkColorMatrixFilter::Create(matrix));
+    SkAutoTUnref<SkColorFilter> filter(cf_make_brightness(amount));
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
 static SkImageFilter* make_grayscale(SkImageFilter* input = nullptr) {
-    SkScalar matrix[20];
-    memset(matrix, 0, 20 * sizeof(SkScalar));
-    matrix[0] = matrix[5] = matrix[10] = 0.2126f;
-    matrix[1] = matrix[6] = matrix[11] = 0.7152f;
-    matrix[2] = matrix[7] = matrix[12] = 0.0722f;
-    matrix[18] = 1.0f;
-    SkAutoTUnref<SkColorFilter> filter(SkColorMatrixFilter::Create(matrix));
+    SkAutoTUnref<SkColorFilter> filter(cf_make_grayscale());
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
 static SkImageFilter* make_mode_blue(SkImageFilter* input = nullptr) {
-    SkAutoTUnref<SkColorFilter> filter(
-        SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrc_Mode));
+    SkAutoTUnref<SkColorFilter> filter(cf_make_colorize(SK_ColorBLUE));
     return SkColorFilterImageFilter::Create(filter, input);
 }
 
@@ -129,3 +187,29 @@ DEF_SIMPLE_GM(colorfilterimagefilter_layer, canvas, 32, 32) {
     canvas->saveLayer(NULL, &p);
     canvas->clear(SK_ColorRED);
 }
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+DEF_SIMPLE_GM(colorfiltershader, canvas, 800, 800) {
+    const SkTDArray<SkColorFilter*>& filters = sk_gm_get_colorfilters();
+    const SkTDArray<SkShader*>& shaders = sk_gm_get_shaders();
+
+    SkPaint paint;
+    SkRect r = SkRect::MakeWH(120, 120);
+
+    canvas->translate(20, 20);
+    for (int y = 0; y < shaders.count(); ++y) {
+        SkShader* shader = shaders[y];
+        
+        canvas->save();
+        for (int x = -1; x < filters.count(); ++x) {
+            SkColorFilter* filter = x >= 0 ? filters[x] : nullptr;
+
+            paint.setShader(shader->newWithColorFilter(filter))->unref();
+            canvas->drawRect(r, paint);
+            canvas->translate(150, 0);
+        }
+        canvas->restore();
+        canvas->translate(0, 150);
+    }
+}