add test for shader text w/ and w/o lcd (and w/ and w/o opaque)



git-svn-id: http://skia.googlecode.com/svn/trunk@2753 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gradtext.cpp b/gm/gradtext.cpp
new file mode 100644
index 0000000..6c75db1
--- /dev/null
+++ b/gm/gradtext.cpp
@@ -0,0 +1,87 @@
+/*
+ * 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"
+
+static SkShader* make_grad(SkScalar width) {
+    SkColor colors[] = { SK_ColorBLACK, SK_ColorBLACK, 0 };
+    SkScalar pos[] = { 0, SK_Scalar1 * 5 / 10, SK_Scalar1 };
+    SkPoint pts[] = { { 0, 0 }, { width, 0 } };
+    return SkGradientShader::CreateLinear(pts, colors, pos,
+                                          SK_ARRAY_COUNT(colors),
+                                          SkShader::kMirror_TileMode);
+}
+
+static SkShader* make_grad2(SkScalar width) {
+    SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
+    SkPoint pts[] = { { 0, 0 }, { width, 0 } };
+    return SkGradientShader::CreateLinear(pts, colors, NULL,
+                                          SK_ARRAY_COUNT(colors),
+                                          SkShader::kMirror_TileMode);
+}
+
+namespace skiagm {
+    
+class GradTextGM : public GM {
+public:
+    GradTextGM () {}
+
+protected:
+
+    virtual SkString onShortName() {
+        return SkString("gradtext");
+    }
+
+    virtual SkISize onISize() { return make_isize(640, 480); }
+
+    static void draw_text(SkCanvas* canvas, const SkPaint& paint) {
+        const char* text = "When in the course of human events";
+        size_t len = strlen(text);
+        canvas->drawText(text, len, 0, 0, paint);
+    }
+
+    static void draw_text3(SkCanvas* canvas, const SkPaint& paint) {
+        SkPaint p(paint);
+
+        p.setAntiAlias(false);
+        draw_text(canvas, p);
+        p.setAntiAlias(true);
+        canvas->translate(0, SkIntToScalar(20));
+        draw_text(canvas, p);
+        p.setLCDRenderText(true);
+        canvas->translate(0, SkIntToScalar(20));
+        draw_text(canvas, p);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) {
+        canvas->translate(SkIntToScalar(20), SkIntToScalar(20));
+
+        //  The blits special-case opaque and non-paque shaders, so test both
+
+        SkPaint paint;
+        paint.setTextSize(SkIntToScalar(16));
+        paint.setShader(make_grad(SkIntToScalar(80)))->unref();
+
+        draw_text3(canvas, paint);
+        canvas->translate(0, SkIntToScalar(40));
+        paint.setShader(make_grad2(SkIntToScalar(80)))->unref();
+        draw_text3(canvas, paint);
+    }
+
+private:
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new GradTextGM; }
+static GMRegistry reg(MyFactory);
+
+}
+