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/*
* 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 "include/core/SkCanvas.h"
#include "samplecode/Sample.h"
#include "src/core/SkPathPriv.h"
#include "tools/ToolUtils.h"
#if SK_SUPPORT_GPU
#include "include/gpu/GrContext.h"
#include "src/gpu/GrClip.h"
#include "src/gpu/GrContextPriv.h"
#include "src/gpu/GrMemoryPool.h"
#include "src/gpu/GrRenderTargetContext.h"
#include "src/gpu/GrRenderTargetContextPriv.h"
#include "src/gpu/tessellate/GrTessellatePathOp.h"
// This sample enables wireframe and visualizes the triangulation generated by
// GrTessellateWedgeShader.
class TessellatedWedge : public Sample {
public:
TessellatedWedge() {
#if 0
fPath.moveTo(1, 0);
int numSides = 32 * 3;
for (int i = 1; i < numSides; ++i) {
float theta = 2*3.1415926535897932384626433832785 * i / numSides;
fPath.lineTo(std::cos(theta), std::sin(theta));
}
fPath.transform(SkMatrix::Scale(200, 200));
fPath.transform(SkMatrix::Translate(300, 300));
#else
fPath.moveTo(100, 200);
fPath.cubicTo(100, 100, 400, 100, 400, 200);
fPath.lineTo(250, 500);
#endif
}
private:
void onDrawContent(SkCanvas*) override;
Sample::Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey) override;
bool onClick(Sample::Click*) override;
bool onChar(SkUnichar) override;
SkString name() override { return SkString("TessellatedWedge"); }
SkMatrix fLastViewMatrix = SkMatrix::I();
SkPath fPath;
GrTessellationPathRenderer::OpFlags fOpFlags = GrTessellationPathRenderer::OpFlags::kWireframe;
class Click;
};
void TessellatedWedge::onDrawContent(SkCanvas* canvas) {
canvas->clear(SK_ColorBLACK);
GrContext* ctx = canvas->getGrContext();
GrRenderTargetContext* rtc = canvas->internal_private_accessTopLayerRenderTargetContext();
SkString error;
if (!rtc || !ctx) {
error = "GPU Only.";
} else if (!ctx->priv().caps()->drawInstancedSupport()) {
error = "Instanced rendering not supported.";
} else if (1 == rtc->numSamples() && !ctx->priv().caps()->mixedSamplesSupport()) {
error = "MSAA/mixed samples only.";
}
if (!error.isEmpty()) {
SkFont font(nullptr, 20);
SkPaint captionPaint;
captionPaint.setColor(SK_ColorWHITE);
canvas->drawString(error.c_str(), 10, 30, font, captionPaint);
return;
}
GrPaint paint;
paint.setColor4f({1,0,1,1});
GrAAType aa;
if (rtc->numSamples() > 1) {
aa = GrAAType::kMSAA;
} else if (rtc->asRenderTargetProxy()->canUseMixedSamples(*ctx->priv().caps())) {
aa = GrAAType::kCoverage;
} else {
aa = GrAAType::kNone;
}
GrOpMemoryPool* pool = ctx->priv().opMemoryPool();
rtc->priv().testingOnly_addDrawOp(pool->allocate<GrTessellatePathOp>(
canvas->getTotalMatrix(), fPath, std::move(paint), aa, fOpFlags));
// Draw the path points.
SkPaint pointsPaint;
pointsPaint.setColor(SK_ColorBLUE);
pointsPaint.setStrokeWidth(8);
SkPath devPath = fPath;
devPath.transform(canvas->getTotalMatrix());
{
SkAutoCanvasRestore acr(canvas, true);
canvas->setMatrix(SkMatrix::I());
canvas->drawPoints(SkCanvas::kPoints_PointMode, devPath.countPoints(),
SkPathPriv::PointData(devPath), pointsPaint);
}
fLastViewMatrix = canvas->getTotalMatrix();
}
class TessellatedWedge::Click : public Sample::Click {
public:
Click(int ptIdx) : fPtIdx(ptIdx) {}
void doClick(SkPath* path) {
if (fPtIdx >= 0) {
SkPoint pt = path->getPoint(fPtIdx);
SkPathPriv::UpdatePathPoint(path, fPtIdx, pt + fCurr - fPrev);
} else {
path->transform(
SkMatrix::Translate(fCurr.x() - fPrev.x(), fCurr.y() - fPrev.y()), path);
}
}
private:
int fPtIdx;
};
Sample::Click* TessellatedWedge::onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey) {
const SkPoint* pts = SkPathPriv::PointData(fPath);
float fuzz = 20 / fLastViewMatrix.getMaxScale();
for (int i = 0; i < fPath.countPoints(); ++i) {
SkPoint screenPoint = pts[i];
if (fabs(x - screenPoint.x()) < fuzz && fabsf(y - screenPoint.y()) < fuzz) {
return new Click(i);
}
}
return new Click(-1);
}
bool TessellatedWedge::onClick(Sample::Click* click) {
Click* myClick = (Click*)click;
myClick->doClick(&fPath);
return true;
}
bool TessellatedWedge::onChar(SkUnichar unichar) {
switch (unichar) {
case 'w':
fOpFlags = (GrTessellationPathRenderer::OpFlags)(
(int)fOpFlags ^ (int)GrTessellationPathRenderer::OpFlags::kWireframe);
return true;
case 'D': {
fPath.dump();
return true;
}
}
return false;
}
Sample* MakeTessellatedWedgeSample() { return new TessellatedWedge; }
static SampleRegistry gTessellatedWedgeSample(MakeTessellatedWedgeSample);
#endif // SK_SUPPORT_GPU
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