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/*
* 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 "SkColorPriv.h"
#include "SkShader.h"
#include "SkArithmeticMode.h"
#include "SkGradientShader.h"
#define WW 100
#define HH 32
static SkBitmap make_bm() {
SkBitmap bm;
bm.allocN32Pixels(WW, HH);
bm.eraseColor(SK_ColorTRANSPARENT);
return bm;
}
static SkBitmap make_src() {
SkBitmap bm = make_bm();
SkCanvas canvas(bm);
SkPaint paint;
SkPoint pts[] = { {0, 0}, {SkIntToScalar(WW), SkIntToScalar(HH)} };
SkColor colors[] = {
SK_ColorTRANSPARENT, SK_ColorGREEN, SK_ColorCYAN,
SK_ColorRED, SK_ColorMAGENTA, SK_ColorWHITE,
};
SkShader* s = SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
SkShader::kClamp_TileMode);
paint.setShader(s)->unref();
canvas.drawPaint(paint);
return bm;
}
static SkBitmap make_dst() {
SkBitmap bm = make_bm();
SkCanvas canvas(bm);
SkPaint paint;
SkPoint pts[] = { {0, SkIntToScalar(HH)}, {SkIntToScalar(WW), 0} };
SkColor colors[] = {
SK_ColorBLUE, SK_ColorYELLOW, SK_ColorBLACK, SK_ColorGREEN,
sk_tool_utils::color_to_565(SK_ColorGRAY)
};
SkShader* s = SkGradientShader::CreateLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors),
SkShader::kClamp_TileMode);
paint.setShader(s)->unref();
canvas.drawPaint(paint);
return bm;
}
static void show_k_text(SkCanvas* canvas, SkScalar x, SkScalar y, const SkScalar k[]) {
SkPaint paint;
paint.setTextSize(SkIntToScalar(24));
paint.setAntiAlias(true);
sk_tool_utils::set_portable_typeface(&paint);
for (int i = 0; i < 4; ++i) {
SkString str;
str.appendScalar(k[i]);
SkScalar width = paint.measureText(str.c_str(), str.size());
canvas->drawText(str.c_str(), str.size(), x, y + paint.getTextSize(), paint);
x += width + SkIntToScalar(10);
}
}
class ArithmodeGM : public skiagm::GM {
public:
ArithmodeGM () {}
protected:
virtual SkString onShortName() {
return SkString("arithmode");
}
virtual SkISize onISize() { return SkISize::Make(640, 572); }
virtual void onDraw(SkCanvas* canvas) {
SkBitmap src = make_src();
SkBitmap dst = make_dst();
const SkScalar one = SK_Scalar1;
static const SkScalar K[] = {
0, 0, 0, 0,
0, 0, 0, one,
0, one, 0, 0,
0, 0, one, 0,
0, one, one, 0,
0, one, -one, 0,
0, one/2, one/2, 0,
0, one/2, one/2, one/4,
0, one/2, one/2, -one/4,
one/4, one/2, one/2, 0,
-one/4, one/2, one/2, 0,
};
const SkScalar* k = K;
const SkScalar* stop = k + SK_ARRAY_COUNT(K);
SkScalar y = 0;
SkScalar gap = SkIntToScalar(src.width() + 20);
while (k < stop) {
SkScalar x = 0;
canvas->drawBitmap(src, x, y, nullptr);
x += gap;
canvas->drawBitmap(dst, x, y, nullptr);
x += gap;
SkRect rect = SkRect::MakeXYWH(x, y, SkIntToScalar(WW), SkIntToScalar(HH));
canvas->saveLayer(&rect, nullptr);
canvas->drawBitmap(dst, x, y, nullptr);
SkXfermode* xfer = SkArithmeticMode::Create(k[0], k[1], k[2], k[3]);
SkPaint paint;
paint.setXfermode(xfer)->unref();
canvas->drawBitmap(src, x, y, &paint);
canvas->restore();
x += gap;
show_k_text(canvas, x, y, k);
k += 4;
y += SkIntToScalar(src.height() + 12);
}
// Draw two special cases to test enforcePMColor. In these cases, we
// draw the dst bitmap twice, the first time it is halved and inverted,
// leading to invalid premultiplied colors. If we enforcePMColor, these
// invalid values should be clamped, and will not contribute to the
// second draw.
for (int i = 0; i < 2; i++) {
const bool enforcePMColor = (i == 0);
SkScalar x = gap;
canvas->drawBitmap(dst, x, y, nullptr);
x += gap;
SkRect rect = SkRect::MakeXYWH(x, y, SkIntToScalar(WW), SkIntToScalar(HH));
canvas->saveLayer(&rect, nullptr);
SkXfermode* xfer1 = SkArithmeticMode::Create(0, -one / 2, 0, 1, enforcePMColor);
SkPaint paint1;
paint1.setXfermode(xfer1)->unref();
canvas->drawBitmap(dst, x, y, &paint1);
SkXfermode* xfer2 = SkArithmeticMode::Create(0, one / 2, -one, 1);
SkPaint paint2;
paint2.setXfermode(xfer2)->unref();
canvas->drawBitmap(dst, x, y, &paint2);
canvas->restore();
x += gap;
// Label
SkPaint paint;
paint.setTextSize(SkIntToScalar(24));
paint.setAntiAlias(true);
sk_tool_utils::set_portable_typeface(&paint);
SkString str(enforcePMColor ? "enforcePM" : "no enforcePM");
canvas->drawText(str.c_str(), str.size(), x, y + paint.getTextSize(), paint);
y += SkIntToScalar(src.height() + 12);
}
}
private:
typedef GM INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
DEF_GM( return new ArithmodeGM; )
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