skia2/gm/sample_matrix_variable.cpp
Mike Reed f3ac2afbb6 Name common cubic resamplers
Useful in client code to document what we're doing as we switch away
from SkFilterQuality.

Change-Id: I05737beb99a567a46a3c3ec418b7f7da71b1ff62
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/366723
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
2021-02-05 19:21:04 +00:00

105 lines
4.2 KiB
C++

/*
* Copyright 2019 Google LLC.
*
* 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/effects/SkGradientShader.h"
#include "src/core/SkMatrixProvider.h"
#include "src/gpu/GrBitmapTextureMaker.h"
#include "src/gpu/GrDirectContextPriv.h"
#include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
#include "src/gpu/ops/GrFillRectOp.h"
#include "tools/Resources.h"
class SampleMatrixVariableEffect : public GrFragmentProcessor {
public:
static constexpr GrProcessor::ClassID CLASS_ID = (GrProcessor::ClassID) 2;
SampleMatrixVariableEffect(std::unique_ptr<GrFragmentProcessor> child,
float xOffset,
float yOffset)
: INHERITED(CLASS_ID, kNone_OptimizationFlags)
, fXOffset(xOffset)
, fYOffset(yOffset) {
this->registerChild(std::move(child), SkSL::SampleUsage::VariableMatrix());
}
const char* name() const override { return "SampleMatrixVariableEffect"; }
std::unique_ptr<GrFragmentProcessor> clone() const override {
SkASSERT(false);
return nullptr;
}
void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override {}
bool onIsEqual(const GrFragmentProcessor& that) const override { return this == &that; }
private:
GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
float fXOffset;
float fYOffset;
using INHERITED = GrFragmentProcessor;
friend class GLSLSampleMatrixVariableEffect;
};
class GLSLSampleMatrixVariableEffect : public GrGLSLFragmentProcessor {
void emitCode(EmitArgs& args) override {
auto& smve = args.fFp.cast<SampleMatrixVariableEffect>();
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
SkString sample1 = this->invokeChildWithMatrix(0, args, "float3x3(1)");
SkString sample2 = this->invokeChildWithMatrix(0, args,
SkStringPrintf("float3x3(1, -1, 0, 1, 0, 0, "
"%g, %g, 1)",
smve.fXOffset,
smve.fYOffset).c_str());
fragBuilder->codeAppendf("return (%s + %s) / 2;\n", sample1.c_str(), sample2.c_str());
}
};
GrGLSLFragmentProcessor* SampleMatrixVariableEffect::onCreateGLSLInstance() const {
return new GLSLSampleMatrixVariableEffect();
}
DEF_SIMPLE_GPU_GM(sample_matrix_variable, ctx, rtCtx, canvas, 512, 256) {
auto draw = [rtCtx](std::unique_ptr<GrFragmentProcessor> baseFP, float ofsX, float ofsY,
int tx, int ty) {
auto fp = std::unique_ptr<GrFragmentProcessor>(
new SampleMatrixVariableEffect(std::move(baseFP), ofsX, ofsY));
GrPaint paint;
paint.setColorFragmentProcessor(std::move(fp));
rtCtx->drawRect(nullptr, std::move(paint), GrAA::kNo, SkMatrix::Translate(tx, ty),
SkRect::MakeIWH(256, 256));
};
{
SkBitmap bmp;
GetResourceAsBitmap("images/mandrill_256.png", &bmp);
GrBitmapTextureMaker maker(ctx, bmp, GrImageTexGenPolicy::kDraw);
auto view = maker.view(GrMipmapped::kNo);
std::unique_ptr<GrFragmentProcessor> imgFP =
GrTextureEffect::Make(std::move(view), bmp.alphaType(), SkMatrix());
draw(std::move(imgFP), -128, 256, 0, 0);
}
{
static constexpr SkColor colors[] = { 0xff00ff00, 0xffff00ff };
const SkPoint pts[] = {{ 256, 0 }, { 512, 0 }};
auto shader = SkGradientShader::MakeLinear(pts, colors, nullptr,
SK_ARRAY_COUNT(colors),
SkTileMode::kRepeat);
SkMatrix matrix;
SkSimpleMatrixProvider matrixProvider(matrix);
GrColorInfo colorInfo;
GrFPArgs args(ctx, matrixProvider, SkSamplingOptions(SkCubicResampler::Mitchell()),
&colorInfo);
std::unique_ptr<GrFragmentProcessor> gradientFP = as_SB(shader)->asFragmentProcessor(args);
draw(std::move(gradientFP), -128, 256, 256, 0);
}
}