add test for colored text drawing (hopefully gamma corrected)

git-svn-id: http://skia.googlecode.com/svn/trunk@3190 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 191 insertions, 0 deletions

diff --git a/gm/gammatext.cpp b/gm/gammatext.cpp
new file mode 100644
index 0000000000..8a655f4c0c
--- /dev/null
+++ b/gm/gammatext.cpp
@@ -0,0 +1,191 @@
+/*
+ * 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 "SkPath.h"
+#include "SkGradientShader.h"
+#include "SkTypeface.h"
+
+static SkShader* make_heatGradient(const SkPoint pts[2]) {
+    const SkColor colors[] = {
+        SK_ColorBLACK, SK_ColorBLUE, SK_ColorCYAN, SK_ColorGREEN,
+        SK_ColorYELLOW, SK_ColorRED, SK_ColorWHITE
+    };
+    const SkColor bw[] = { SK_ColorBLACK, SK_ColorWHITE };
+
+    return SkGradientShader::CreateLinear(pts, bw, NULL,
+                                          SK_ARRAY_COUNT(bw),
+                                          SkShader::kClamp_TileMode);
+}
+
+static bool setFont(SkPaint* paint, const char name[]) {
+    SkTypeface* tf = SkTypeface::CreateFromName(name, SkTypeface::kNormal);
+    if (tf) {
+        paint->setTypeface(tf)->unref();
+        return true;
+    }
+}
+
+#ifdef SK_BUILD_FOR_MAC
+#import <ApplicationServices/ApplicationServices.h>
+#define BITMAP_INFO_RGB     (kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host)
+
+static CGContextRef makeCG(const SkBitmap& bm) {
+    if (SkBitmap::kARGB_8888_Config != bm.config() ||
+        NULL == bm.getPixels()) {
+        return NULL;
+    }
+    CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
+    CGContextRef cg = CGBitmapContextCreate(bm.getPixels(), bm.width(), bm.height(),
+                                            8, bm.rowBytes(), space, BITMAP_INFO_RGB);
+    CFRelease(space);
+    
+    CGContextSetAllowsFontSubpixelQuantization(cg, false);
+    CGContextSetShouldSubpixelQuantizeFonts(cg, false);
+    
+    return cg;
+}
+
+extern CTFontRef SkTypeface_GetCTFontRef(const SkTypeface* face);
+
+static CGFontRef typefaceToCGFont(const SkTypeface* face) {
+    if (NULL == face) {
+        return 0;
+    }
+
+    CTFontRef ct = SkTypeface_GetCTFontRef(face);
+    return CTFontCopyGraphicsFont(ct, NULL);
+}
+
+static void cgSetPaintForText(CGContextRef cg, const SkPaint& paint) {
+    SkColor c = paint.getColor();
+    CGFloat rgba[] = {
+        SkColorGetB(c) / 255.0,
+        SkColorGetG(c) / 255.0,
+        SkColorGetR(c) / 255.0,
+        SkColorGetA(c) / 255.0,
+    };
+    CGContextSetRGBFillColor(cg, rgba[0], rgba[1], rgba[2], rgba[3]);
+
+    CGContextSetTextDrawingMode(cg, kCGTextFill);
+    CGContextSetFont(cg, typefaceToCGFont(paint.getTypeface()));
+    CGContextSetFontSize(cg, SkScalarToFloat(paint.getTextSize()));
+
+    CGContextSetAllowsFontSubpixelPositioning(cg, paint.isSubpixelText());
+    CGContextSetShouldSubpixelPositionFonts(cg, paint.isSubpixelText());
+    
+    CGContextSetShouldAntialias(cg, paint.isAntiAlias());
+    CGContextSetShouldSmoothFonts(cg, paint.isLCDRenderText());
+}
+
+static void cgDrawText(CGContextRef cg, const void* text, size_t len,
+                       float x, float y, const SkPaint& paint) {
+    if (cg) {
+        cgSetPaintForText(cg, paint);
+
+        uint16_t glyphs[200];
+        int count = paint.textToGlyphs(text, len, glyphs);
+
+        CGContextShowGlyphsAtPoint(cg, x, y, glyphs, count);
+    }
+}
+#endif
+
+namespace skiagm {
+
+/**
+   Test a set of clipping problems discovered while writing blitAntiRect,
+   and test all the code paths through the clipping blitters.
+   Each region should show as a blue center surrounded by a 2px green
+   border, with no red.
+*/
+    
+#define HEIGHT 480
+
+class GammaTextGM : public GM {
+public:
+    GammaTextGM() {
+
+    }
+
+protected:
+    virtual SkString onShortName() {
+        return SkString("gammatext");
+    }
+
+    virtual SkISize onISize() {
+        return make_isize(1024, HEIGHT);
+    }
+
+    static void drawGrad(SkCanvas* canvas) {
+        SkPoint pts[] = { { 0, 0 }, { 0, HEIGHT } };
+#if 0
+        const SkColor colors[] = { SK_ColorBLACK, SK_ColorWHITE };
+        SkShader* s = SkGradientShader::CreateLinear(pts, colors, NULL, 2, SkShader::kClamp_TileMode);
+#else
+        SkShader* s = make_heatGradient(pts);
+#endif
+        
+        canvas->clear(SK_ColorRED);
+        SkPaint paint;
+        paint.setShader(s)->unref();
+        SkRect r = { 0, 0, 1024, HEIGHT };
+        canvas->drawRect(r, paint);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+#ifdef SK_BUILD_FOR_MAC
+        CGContextRef cg = makeCG(canvas->getDevice()->accessBitmap(false));
+#endif
+        
+        drawGrad(canvas);
+
+        const SkColor fg[] = {
+            0xFFFFFFFF,
+            0xFFFFFF00, 0xFFFF00FF, 0xFF00FFFF,
+            0xFFFF0000, 0xFF00FF00, 0xFF0000FF,
+            0xFF000000,
+        };
+        
+        const char* text = "Hamburgefons";
+        size_t len = strlen(text);
+
+        SkPaint paint;
+        setFont(&paint, "Times");
+        paint.setTextSize(SkIntToScalar(16));
+        paint.setAntiAlias(true);
+        paint.setLCDRenderText(true);
+
+        SkScalar x = 10;
+        for (size_t i = 0; i < SK_ARRAY_COUNT(fg); ++i) {
+            paint.setColor(fg[i]);
+            
+            SkScalar y = 40;
+            SkScalar stopy = HEIGHT;
+            while (y < stopy) {
+#if 1
+                canvas->drawText(text, len, x, y, paint);
+#else
+                cgDrawText(cg, text, len, x, HEIGHT - y, paint);
+#endif
+                y += paint.getTextSize() * 2;
+            }
+            x += SkIntToScalar(1024) / SK_ARRAY_COUNT(fg);
+        }
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new GammaTextGM; }
+static GMRegistry reg(MyFactory);
+
+}