/*
* Copyright 2012 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 "SkColorPriv.h"
#include "SkCanvas.h"
#include "SkGradientShader.h"
#include "SkGraphics.h"
#include "SkImage.h"
#include "SkShader.h"
#include "SkString.h"
#include "SkTDArray.h"
static sk_sp<SkShader> make_shader(SkBlendMode mode) {
SkPoint pts[2];
SkColor colors[2];
pts[0].set(0, 0);
pts[1].set(SkIntToScalar(100), 0);
colors[0] = SK_ColorRED;
colors[1] = SK_ColorBLUE;
auto shaderA = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
pts[0].set(0, 0);
pts[1].set(0, SkIntToScalar(100));
colors[0] = SK_ColorBLACK;
colors[1] = SkColorSetARGB(0x80, 0, 0, 0);
auto shaderB = SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
return SkShader::MakeComposeShader(std::move(shaderA), std::move(shaderB), mode);
}
class ComposeShaderGM : public skiagm::GM {
public:
ComposeShaderGM() {
fShader = make_shader(SkBlendMode::kDstIn);
}
protected:
SkString onShortName() override {
return SkString("composeshader");
}
SkISize onISize() override {
return SkISize::Make(120, 120);
}
void onDraw(SkCanvas* canvas) override {
SkPaint paint;
paint.setColor(SK_ColorGREEN);
canvas->drawRect(SkRect::MakeWH(100, 100), paint);
paint.setShader(fShader);
canvas->drawRect(SkRect::MakeWH(100, 100), paint);
}
protected:
sk_sp<SkShader> fShader;
private:
typedef GM INHERITED ;
};
DEF_GM( return new ComposeShaderGM; )
class ComposeShaderAlphaGM : public skiagm::GM {
public:
ComposeShaderAlphaGM() {}
protected:
SkString onShortName() override {
return SkString("composeshader_alpha");
}
SkISize onISize() override {
return SkISize::Make(750, 220);
}
void onDraw(SkCanvas* canvas) override {
sk_sp<SkShader> shaders[] = {
make_shader(SkBlendMode::kDstIn),
make_shader(SkBlendMode::kSrcOver),
};
SkPaint paint;
paint.setColor(SK_ColorGREEN);
const SkRect r = SkRect::MakeXYWH(5, 5, 100, 100);
for (size_t y = 0; y < SK_ARRAY_COUNT(shaders); ++y) {
canvas->save();
for (int alpha = 0xFF; alpha > 0; alpha -= 0x28) {
paint.setAlpha(0xFF);
paint.setShader(nullptr);
canvas->drawRect(r, paint);
paint.setAlpha(alpha);
paint.setShader(shaders[y]);
canvas->drawRect(r, paint);
canvas->translate(r.width() + 5, 0);
}
canvas->restore();
canvas->translate(0, r.height() + 5);
}
}
private:
typedef GM INHERITED ;
};
DEF_GM( return new ComposeShaderAlphaGM; )
// creates a square bitmap with red background and a green circle in the center
static void draw_color_bm(SkBitmap* bm, int length) {
SkPaint paint;
paint.setColor(SK_ColorGREEN);
bm->allocN32Pixels(length, length);
bm->eraseColor(SK_ColorRED);
SkCanvas canvas(*bm);
canvas.drawCircle(SkIntToScalar(length/2), SkIntToScalar(length/2), SkIntToScalar(length/2),
paint);
}
// creates a square alpha8 bitmap with transparent background and an opaque circle in the center
static void draw_alpha8_bm(SkBitmap* bm, int length) {
SkPaint circlePaint;
circlePaint.setColor(SK_ColorBLACK);
bm->allocPixels(SkImageInfo::MakeA8(length, length));
bm->eraseColor(SK_ColorTRANSPARENT);
SkCanvas canvas(*bm);
canvas.drawCircle(SkIntToScalar(length/2), SkIntToScalar(length/2), SkIntToScalar(length/4),
circlePaint);
}
// creates a linear gradient shader
static sk_sp<SkShader> make_linear_gradient_shader(int length) {
SkPoint pts[2];
SkColor colors[2];
pts[0].set(0, 0);
pts[1].set(SkIntToScalar(length), 0);
colors[0] = SK_ColorBLUE;
colors[1] = SkColorSetARGB(0, 0, 0, 0xFF);
return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
}
class ComposeShaderBitmapGM : public skiagm::GM {
public:
ComposeShaderBitmapGM() {}
protected:
void onOnceBeforeDraw() override {
draw_color_bm(&fColorBitmap, squareLength);
draw_alpha8_bm(&fAlpha8Bitmap, squareLength);
SkMatrix s;
s.reset();
fColorBitmapShader = SkShader::MakeBitmapShader(fColorBitmap, SkShader::kRepeat_TileMode,
SkShader::kRepeat_TileMode, &s);
fAlpha8BitmapShader = SkShader::MakeBitmapShader(fAlpha8Bitmap, SkShader::kRepeat_TileMode,
SkShader::kRepeat_TileMode, &s);
fLinearGradientShader = make_linear_gradient_shader(squareLength);
}
SkString onShortName() override {
return SkString("composeshader_bitmap");
}
SkISize onISize() override {
return SkISize::Make(7 * (squareLength + 5), 2 * (squareLength + 5));
}
void onDraw(SkCanvas* canvas) override {
SkBlendMode mode = SkBlendMode::kDstOver;
sk_sp<SkShader> shaders[] = {
// gradient should appear over color bitmap
SkShader::MakeComposeShader(fLinearGradientShader, fColorBitmapShader, mode),
// gradient should appear over alpha8 bitmap colorized by the paint color
SkShader::MakeComposeShader(fLinearGradientShader, fAlpha8BitmapShader, mode),
};
SkPaint paint;
paint.setColor(SK_ColorYELLOW);
const SkRect r = SkRect::MakeXYWH(0, 0, SkIntToScalar(squareLength),
SkIntToScalar(squareLength));
for (size_t y = 0; y < SK_ARRAY_COUNT(shaders); ++y) {
canvas->save();
for (int alpha = 0xFF; alpha > 0; alpha -= 0x28) {
paint.setAlpha(alpha);
paint.setShader(shaders[y]);
canvas->drawRect(r, paint);
canvas->translate(r.width() + 5, 0);
}
canvas->restore();
canvas->translate(0, r.height() + 5);
}
}
private:
/** This determines the length and width of the bitmaps used in the ComposeShaders. Values
* above 20 may cause an SkASSERT to fail in SkSmallAllocator. However, larger values will
* work in a release build. You can change this parameter and then compile a release build
* to have this GM draw larger bitmaps for easier visual inspection.
*/
static constexpr int squareLength = 20;
SkBitmap fColorBitmap;
SkBitmap fAlpha8Bitmap;
sk_sp<SkShader> fColorBitmapShader;
sk_sp<SkShader> fAlpha8BitmapShader;
sk_sp<SkShader> fLinearGradientShader;
typedef GM INHERITED;
};
DEF_GM( return new ComposeShaderBitmapGM; )
DEF_SIMPLE_GM(composeshader_bitmap2, canvas, 200, 200) {
int width = 255;
int height = 255;
SkTDArray<uint8_t> dst8Storage;
dst8Storage.setCount(width * height);
SkTDArray<uint32_t> dst32Storage;
dst32Storage.setCount(width * height * sizeof(int32_t));
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
dst8Storage[y * width + x] = (y + x) / 2;
dst32Storage[y * width + x] = SkPackARGB32(0xFF, x, y, 0);
}
}
SkPaint paint;
paint.setAntiAlias(true);
paint.setColor(SK_ColorBLUE);
SkRect r = {0, 0, SkIntToScalar(width), SkIntToScalar(height)};
canvas->drawRect(r, paint);
SkBitmap skBitmap, skMask;
SkImageInfo imageInfo = SkImageInfo::Make(width, height,
SkColorType::kN32_SkColorType, kPremul_SkAlphaType);
skBitmap.installPixels(imageInfo, dst32Storage.begin(), width * sizeof(int32_t),
nullptr, nullptr);
imageInfo = SkImageInfo::Make(width, height,
SkColorType::kAlpha_8_SkColorType, kPremul_SkAlphaType);
skMask.installPixels(imageInfo, dst8Storage.begin(), width, nullptr, nullptr);
sk_sp<SkImage> skSrc = SkImage::MakeFromBitmap(skBitmap);
sk_sp<SkImage> skMaskImage = SkImage::MakeFromBitmap(skMask);
paint.setShader(
SkShader::MakeComposeShader(skMaskImage->makeShader(), skSrc->makeShader(),
SkBlendMode::kSrcIn));
canvas->drawRect(r, paint);
}
///////////////////////////////////////////////////////////////////////////////////////////////////
static sk_sp<SkShader> make_src_shader(SkScalar size) {
const SkPoint pts[] = { { 0, 0 }, { 0, size } };
const SkColor colors[] = { 0xFF0000FF, 0x000000FF };
return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
}
static sk_sp<SkShader> make_dst_shader(SkScalar size) {
const SkPoint pts[] = { { 0, 0 }, { size, 0 } };
const SkColor colors[] = { SK_ColorRED, 0x00FF0000 };
return SkGradientShader::MakeLinear(pts, colors, nullptr, 2, SkShader::kClamp_TileMode);
}
const SkScalar gCellSize = 100;
static void draw_cell(SkCanvas* canvas, sk_sp<SkShader> src, sk_sp<SkShader> dst,
SkBlendMode mode, SkAlpha alpha) {
const SkRect r = SkRect::MakeWH(gCellSize, gCellSize);
SkPaint p;
p.setAlpha(alpha);
SkAutoCanvasRestore acr(canvas, false);
canvas->saveLayer(&r, &p);
p.setAlpha(0xFF);
p.setShader(dst);
p.setBlendMode(SkBlendMode::kSrc);
canvas->drawRect(r, p);
p.setShader(src);
p.setBlendMode(mode);
canvas->drawRect(r, p);
}
static void draw_composed(SkCanvas* canvas, sk_sp<SkShader> src, sk_sp<SkShader> dst,
SkBlendMode mode, SkAlpha alpha) {
SkPaint p;
p.setAlpha(alpha);
p.setShader(SkShader::MakeCompose(dst, src, mode));
canvas->drawRect(SkRect::MakeWH(gCellSize, gCellSize), p);
}
static void draw_pair(SkCanvas* canvas, sk_sp<SkShader> src, sk_sp<SkShader> dst,
SkBlendMode mode) {
SkAutoCanvasRestore acr(canvas, true);
const SkScalar gap = 4;
SkRect r = SkRect::MakeWH(2 * gCellSize + gap, 2 * gCellSize + gap);
r.outset(gap + 1.5f, gap + 1.5f);
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
canvas->drawRect(r, p); // border
SkAlpha alpha = 0xFF;
for (int y = 0; y < 2; ++y) {
draw_cell(canvas, src, dst, mode, alpha);
canvas->save();
canvas->translate(gCellSize + gap, 0);
draw_composed(canvas, src, dst, mode, alpha);
canvas->restore();
canvas->translate(0, gCellSize + gap);
alpha = 0x80;
}
}
DEF_SIMPLE_GM(composeshader_grid, canvas, 882, 882) {
auto src = make_src_shader(gCellSize);
auto dst = make_dst_shader(gCellSize);
const SkScalar margin = 15;
const SkScalar dx = 2*gCellSize + margin;
const SkScalar dy = 2*gCellSize + margin;
canvas->translate(margin, margin);
canvas->save();
for (int m = 0; m < 16; ++m) {
SkBlendMode mode = static_cast<SkBlendMode>(m);
draw_pair(canvas, src, dst, mode);
if ((m % 4) == 3) {
canvas->restore();
canvas->translate(0, dy);
canvas->save();
} else {
canvas->translate(dx, 0);
}
}
canvas->restore();
}