| /* |
| * 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 |
| |
| #ifdef SK_SUPPORT_LEGACY_ARITHMETICMODE |
| 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, |
| }; |
| paint.setShader(SkGradientShader::MakeLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors), |
| SkShader::kClamp_TileMode)); |
| 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) |
| }; |
| paint.setShader(SkGradientShader::MakeLinear(pts, colors, nullptr, SK_ARRAY_COUNT(colors), |
| SkShader::kClamp_TileMode)); |
| 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(); |
| |
| constexpr SkScalar one = SK_Scalar1; |
| constexpr 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); |
| SkPaint paint; |
| paint.setXfermode(SkArithmeticMode::Make(k[0], k[1], k[2], k[3])); |
| 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); |
| SkPaint paint1; |
| paint1.setXfermode(SkArithmeticMode::Make(0, -one / 2, 0, 1, enforcePMColor)); |
| canvas->drawBitmap(dst, x, y, &paint1); |
| SkPaint paint2; |
| paint2.setXfermode(SkArithmeticMode::Make(0, one / 2, -one, 1)); |
| 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; ) |
| #endif |