Add SkTableColorFilter, as a foundation for several SVG filters

git-svn-id: http://skia.googlecode.com/svn/trunk@2933 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 139 insertions, 0 deletions

diff --git a/gm/tablecolorfilter.cpp b/gm/tablecolorfilter.cpp
new file mode 100644
index 0000000000..c882fe6672
--- /dev/null
+++ b/gm/tablecolorfilter.cpp
@@ -0,0 +1,139 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkCanvas.h"
+#include "SkGradientShader.h"
+#include "SkTableColorFilter.h"
+
+static void make_bm0(SkBitmap* bm) {
+    int W = 120;
+    int H = 120;
+    bm->setConfig(SkBitmap::kARGB_8888_Config, W, H);
+    bm->allocPixels();
+    bm->eraseColor(0);
+    
+    SkCanvas canvas(*bm);
+    SkPaint paint;
+    SkPoint pts[] = { 0, 0, SkIntToScalar(W), SkIntToScalar(H) };
+    SkColor colors[] = {
+        SK_ColorBLACK, SK_ColorGREEN, SK_ColorCYAN,
+        SK_ColorRED, 0, SK_ColorBLUE, SK_ColorWHITE
+    };
+    SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, SK_ARRAY_COUNT(colors),
+                                                 SkShader::kClamp_TileMode);
+    paint.setShader(s)->unref();
+    canvas.drawPaint(paint);
+}
+static void make_bm1(SkBitmap* bm) {
+    int W = 120;
+    int H = 120;
+    bm->setConfig(SkBitmap::kARGB_8888_Config, W, H);
+    bm->allocPixels();
+    bm->eraseColor(0);
+    
+    SkCanvas canvas(*bm);
+    SkPaint paint;
+    SkScalar cx = SkIntToScalar(W)/2;
+    SkScalar cy = SkIntToScalar(H)/2;
+    SkColor colors[] = {
+        SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE,
+    };
+    SkShader* s = SkGradientShader::CreateRadial(SkPoint::Make(SkIntToScalar(W)/2,
+                                                               SkIntToScalar(H)/2),
+                                                 SkIntToScalar(W)/2, colors, NULL, SK_ARRAY_COUNT(colors),
+                                                 SkShader::kClamp_TileMode);
+    paint.setShader(s)->unref();
+    paint.setAntiAlias(true);
+    canvas.drawCircle(cx, cy, cx, paint);
+}
+
+static void make_table0(uint8_t table[]) {
+    for (int i = 0; i < 256; ++i) {
+        int n = i >> 5;
+        table[i] = (n << 5) | (n << 2) | (n >> 1);
+    }
+}
+static void make_table1(uint8_t table[]) {
+    for (int i = 0; i < 256; ++i) {
+        table[i] = i * i / 255;
+    }
+}
+static void make_table2(uint8_t table[]) {
+    for (int i = 0; i < 256; ++i) {
+        float fi = i / 255.0f;
+        table[i] = sqrtf(fi) * 255;
+    }
+}
+
+static SkColorFilter* make_cf0() {
+    uint8_t table[256]; make_table0(table);
+    return SkTableColorFilter::Create(table);
+}
+static SkColorFilter* make_cf1() {
+    uint8_t table[256]; make_table1(table);
+    return SkTableColorFilter::Create(table);
+}
+static SkColorFilter* make_cf2() {
+    uint8_t table[256]; make_table2(table);
+    return SkTableColorFilter::Create(table);
+}
+static SkColorFilter* make_cf3() {
+    uint8_t table0[256]; make_table0(table0);
+    uint8_t table1[256]; make_table1(table1);
+    uint8_t table2[256]; make_table2(table2);
+    return SkTableColorFilter::CreateARGB(NULL, table0, table1, table2);
+}
+
+class TableColorFilterGM : public skiagm::GM {
+public:
+    TableColorFilterGM() {}
+    
+protected:
+    virtual SkString onShortName() {
+        return SkString("tablecolorfilter");
+    }
+    
+    virtual SkISize onISize() {
+        return SkISize::Make(640, 480);
+    }
+    
+    virtual void onDraw(SkCanvas* canvas) {
+        canvas->drawColor(0xFFDDDDDD);
+        canvas->translate(20, 20);
+        
+        SkScalar x = 0, y = 0;
+        
+        static void (*gMakers[])(SkBitmap*) = { make_bm0, make_bm1 };
+        for (size_t maker = 0; maker < SK_ARRAY_COUNT(gMakers); ++maker) {
+            SkBitmap bm;
+            gMakers[maker](&bm);
+            
+            SkPaint paint;
+            x = 0;
+            canvas->drawBitmap(bm, x, y, &paint);
+            paint.setColorFilter(make_cf0())->unref();  x += bm.width() * 9 / 8;
+            canvas->drawBitmap(bm, x, y, &paint);
+            paint.setColorFilter(make_cf1())->unref();  x += bm.width() * 9 / 8;
+            canvas->drawBitmap(bm, x, y, &paint);
+            paint.setColorFilter(make_cf2())->unref();  x += bm.width() * 9 / 8;
+            canvas->drawBitmap(bm, x, y, &paint);
+            paint.setColorFilter(make_cf3())->unref();  x += bm.width() * 9 / 8;
+            canvas->drawBitmap(bm, x, y, &paint);
+            
+            y += bm.height() * 9 / 8;
+        }
+    }
+    
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static skiagm::GM* MyFactory(void*) { return new TableColorFilterGM; }
+static skiagm::GMRegistry reg(MyFactory);