skia2/gm/localmatrixshader.cpp

213 lines
8.3 KiB
C++
Raw Normal View History

/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "gm/gm.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkBlendMode.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkImage.h"
#include "include/core/SkImageInfo.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkSurface.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkGradientShader.h"
#include "tools/Resources.h"
#include "tools/ToolUtils.h"
static sk_sp<SkImage> make_image(SkCanvas* rootCanvas) {
static constexpr SkScalar kSize = 50;
SkImageInfo info = SkImageInfo::MakeN32Premul(kSize, kSize);
auto surface = ToolUtils::makeSurface(rootCanvas, info);
SkPaint p;
p.setAntiAlias(true);
p.setColor(SK_ColorGREEN);
surface->getCanvas()->drawCircle(kSize / 2, kSize / 2, kSize / 2, p);
p.setStyle(SkPaint::kStroke_Style);
p.setColor(SK_ColorRED);
surface->getCanvas()->drawLine(kSize * .25f, kSize * .50f, kSize * .75f, kSize * .50f, p);
surface->getCanvas()->drawLine(kSize * .50f, kSize * .25f, kSize * .50f, kSize * .75f, p);
return surface->makeImageSnapshot();
}
DEF_SIMPLE_GM(localmatrixshader_nested, canvas, 450, 1200) {
auto image = make_image(canvas);
using FactoryT = sk_sp<SkShader> (*)(const sk_sp<SkImage>&,
const SkMatrix& inner,
const SkMatrix& outer);
static const FactoryT gFactories[] = {
// SkLocalMatrixShader(SkImageShader(inner), outer)
[](const sk_sp<SkImage>& img, const SkMatrix& inner, const SkMatrix& outer) {
return img->makeShader(SkSamplingOptions(), inner)->makeWithLocalMatrix(outer);
},
// SkLocalMatrixShader(SkLocalMatrixShader(SkImageShader(I), inner), outer)
[](const sk_sp<SkImage>& img, const SkMatrix& inner, const SkMatrix& outer) {
return img->makeShader(SkSamplingOptions())->makeWithLocalMatrix(inner)->makeWithLocalMatrix(outer);
},
// SkLocalMatrixShader(SkComposeShader(SkImageShader(inner)), outer)
[](const sk_sp<SkImage>& img, const SkMatrix& inner, const SkMatrix& outer) {
return SkShaders::Blend(SkBlendMode::kSrcOver,
SkShaders::Color(SK_ColorTRANSPARENT),
img->makeShader(SkSamplingOptions(), inner))
->makeWithLocalMatrix(outer);
},
// SkLocalMatrixShader(SkComposeShader(SkLocalMatrixShader(SkImageShader(I), inner)), outer)
[](const sk_sp<SkImage>& img, const SkMatrix& inner, const SkMatrix& outer) {
return SkShaders::Blend(SkBlendMode::kSrcOver,
SkShaders::Color(SK_ColorTRANSPARENT),
img->makeShader(SkSamplingOptions())->makeWithLocalMatrix(inner))
->makeWithLocalMatrix(outer);
},
};
static const auto inner = SkMatrix::Scale(2, 2),
outer = SkMatrix::Translate(20, 20);
SkPaint border;
border.setAntiAlias(true);
border.setStyle(SkPaint::kStroke_Style);
auto rect = SkRect::Make(image->bounds());
SkAssertResult(SkMatrix::Concat(inner, outer).mapRect(&rect));
const auto drawColumn = [&]() {
SkAutoCanvasRestore acr(canvas, true);
for (const auto& f : gFactories) {
SkPaint p;
p.setShader(f(image, inner, outer));
canvas->drawRect(rect, p);
canvas->drawRect(rect, border);
canvas->translate(0, rect.height() * 1.5f);
}
};
drawColumn();
{
SkAutoCanvasRestore acr(canvas, true);
canvas->translate(0, rect.height() * SK_ARRAY_COUNT(gFactories) * 1.5f);
drawColumn();
}
canvas->translate(rect.width() * 1.5f, 0);
canvas->scale(2, 2);
drawColumn();
}
DEF_SIMPLE_GM(localmatrixshader_persp, canvas, 542, 266) {
auto image = GetResourceAsImage("images/yellow_rose.png");
SkBitmap downsized;
downsized.allocPixels(image->imageInfo().makeWH(128, 128));
image->scalePixels(downsized.pixmap(), SkSamplingOptions(SkFilterMode::kLinear));
image = downsized.asImage();
SkRect imgRect = SkRect::MakeIWH(image->width(), image->height());
// scale matrix
SkMatrix scale = SkMatrix::Scale(1.f / 5.f, 1.f / 5.f);
// perspective matrix
SkPoint src[4];
imgRect.toQuad(src);
SkPoint dst[4] = {{0, 10.f},
{image->width() + 28.f, -100.f},
{image->width() - 28.f, image->height() + 100.f},
{0.f, image->height() - 10.f}};
SkMatrix persp;
SkAssertResult(persp.setPolyToPoly(src, dst, 4));
// combined persp * scale
SkMatrix perspScale = SkMatrix::Concat(persp, scale);
auto draw = [&](sk_sp<SkShader> shader, bool applyPerspToCTM) {
canvas->save();
canvas->clipRect(imgRect);
if (applyPerspToCTM) {
canvas->concat(persp);
}
SkPaint imgShaderPaint;
imgShaderPaint.setShader(std::move(shader));
canvas->drawPaint(imgShaderPaint);
canvas->restore();
canvas->translate(10.f + image->width(), 0.f); // advance
};
// SkImageShader
canvas->save();
// 4 variants that all attempt to apply sample at persp * scale w/ an image shader
// 1. scale provided to SkImage::makeShader(...) but drawn with persp
auto s1 = image->makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat,
SkSamplingOptions(), &scale);
draw(s1, true);
// 2. persp provided to SkImage::makeShader, then wrapped in scale makeWithLocalMatrix
// These pre-concat, so it ends up as persp * scale.
auto s2 = image->makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat,
SkSamplingOptions(), &persp)
->makeWithLocalMatrix(scale);
draw(s2, false);
// 3. Providing pre-computed persp*scale to SkImage::makeShader()
auto s3 = image->makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat,
SkSamplingOptions(), &perspScale);
draw(s3, false);
// 4. Providing pre-computed persp*scale to makeWithLocalMatrix
auto s4 = image->makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat, SkSamplingOptions())
->makeWithLocalMatrix(perspScale);
draw(s4, false);
canvas->restore();
canvas->translate(0.f, 10.f + image->height()); // advance to next row
// SkGradientShader
const SkColor kGradColors[] = { SK_ColorBLACK, SK_ColorTRANSPARENT };
canvas->save();
// 1. scale provided to Make, drawn with persp
auto g1 = SkGradientShader::MakeRadial({imgRect.centerX(), imgRect.centerY()},
imgRect.width() / 2.f, kGradColors, nullptr, 2,
SkTileMode::kRepeat, 0, &scale);
draw(g1, true);
// 2. persp provided to Make, then wrapped with makeWithLocalMatrix (pre-concat as before).
auto g2 = SkGradientShader::MakeRadial({imgRect.centerX(), imgRect.centerY()},
imgRect.width() / 2.f, kGradColors, nullptr, 2,
SkTileMode::kRepeat, 0, &persp)
->makeWithLocalMatrix(scale);
draw(g2, false);
// 3. Provide per-computed persp*scale to Make
auto g3 = SkGradientShader::MakeRadial({imgRect.centerX(), imgRect.centerY()},
imgRect.width() / 2.f, kGradColors, nullptr, 2,
SkTileMode::kRepeat, 0, &perspScale);
draw(g3, false);
// 4. Providing pre-computed persp*scale to makeWithLocalMatrix
auto g4 = SkGradientShader::MakeRadial({imgRect.centerX(), imgRect.centerY()},
imgRect.width() / 2.f, kGradColors, nullptr, 2,
SkTileMode::kRepeat)
->makeWithLocalMatrix(perspScale);
draw(g4, false);
canvas->restore();
}