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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
// This test only works with the GPU backend.
#include "gm.h"
#if SK_SUPPORT_GPU && 0 // Can be enabled when cubic effect is checked in.
#include "GrContext.h"
#include "GrPathUtils.h"
#include "GrTest.h"
#include "SkColorPriv.h"
#include "SkDevice.h"
// Position & KLM line eq values. These are the vertex attributes for Bezier curves. The last value
// of the Vec4f is ignored.
extern const GrVertexAttrib kAttribs[] = {
{kVec2f_GrVertexAttribType, 0, kPosition_GrVertexAttribBinding},
{kVec4f_GrVertexAttribType, sizeof(GrPoint), kEffect_GrVertexAttribBinding}
};
static inline SkScalar eval_line(const SkPoint& p, const SkScalar lineEq[3], SkScalar sign) {
return sign * (lineEq[0] * p.fX + lineEq[1] * p.fY + lineEq[2]);
}
namespace skiagm {
/**
* This GM directly exercises effects that draw Bezier curves in the GPU backend.
*/
class BezierEffects : public GM {
public:
BezierEffects() {
this->setBGColor(0xFFFFFFFF);
}
protected:
virtual SkString onShortName() SK_OVERRIDE {
return SkString("bezier_effects");
}
virtual SkISize onISize() SK_OVERRIDE {
return make_isize(800, 800);
}
virtual uint32_t onGetFlags() const SK_OVERRIDE {
// This is a GPU-specific GM.
return kGPUOnly_Flag;
}
virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
SkDevice* device = canvas->getTopDevice();
GrRenderTarget* rt = device->accessRenderTarget();
if (NULL == rt) {
return;
}
GrContext* context = rt->getContext();
if (NULL == context) {
return;
}
struct Vertex {
SkPoint fPosition;
float fKLM[4]; // The last value is ignored. The effect expects a vec4f.
};
static const int kNumCubics = 10;
SkMWCRandom rand;
int numCols = SkScalarCeilToInt(SkScalarSqrt(SkIntToScalar(kNumCubics)));
int numRows = SkScalarCeilToInt(SkIntToScalar(kNumCubics) / numCols);
SkScalar w = SkIntToScalar(rt->width()) / numCols;
SkScalar h = SkIntToScalar(rt->height()) / numRows;
int row = 0;
int col = 0;
for (int i = 0; i < kNumCubics; ++i) {
SkScalar x = SkScalarMul(col, w);
SkScalar y = SkScalarMul(row, h);
SkPoint controlPts[] = {
{x + rand.nextRangeF(0, w), y + rand.nextRangeF(0, h)},
{x + rand.nextRangeF(0, w), y + rand.nextRangeF(0, h)},
{x + rand.nextRangeF(0, w), y + rand.nextRangeF(0, h)},
{x + rand.nextRangeF(0, w), y + rand.nextRangeF(0, h)}
};
SkPoint chopped[10];
SkScalar klmEqs[9];
SkScalar klmSigns[3];
int cnt = GrPathUtils::chopCubicAtLoopIntersection(controlPts,
chopped,
klmEqs,
klmSigns,
controlPts);
SkPaint ctrlPtPaint;
ctrlPtPaint.setColor(rand.nextU() | 0xFF000000);
for (int i = 0; i < 4; ++i) {
canvas->drawCircle(controlPts[i].fX, controlPts[i].fY, 6.f, ctrlPtPaint);
}
SkPaint polyPaint;
polyPaint.setColor(0xffA0A0A0);
polyPaint.setStrokeWidth(0);
polyPaint.setStyle(SkPaint::kStroke_Style);
canvas->drawPoints(SkCanvas::kPolygon_PointMode, 4, controlPts, polyPaint);
SkPaint choppedPtPaint;
choppedPtPaint.setColor(~ctrlPtPaint.getColor() | 0xFF000000);
for (int c = 0; c < cnt; ++c) {
SkPoint* pts = chopped + 3 * c;
for (int i = 0; i < 4; ++i) {
canvas->drawCircle(pts[i].fX, pts[i].fY, 3.f, choppedPtPaint);
}
SkRect bounds;
bounds.set(pts, 4);
SkPaint boundsPaint;
boundsPaint.setColor(0xff808080);
boundsPaint.setStrokeWidth(0);
boundsPaint.setStyle(SkPaint::kStroke_Style);
canvas->drawRect(bounds, boundsPaint);
Vertex verts[4];
verts[0].fPosition.setRectFan(bounds.fLeft, bounds.fTop,
bounds.fRight, bounds.fBottom,
sizeof(Vertex));
for (int v = 0; v < 4; ++v) {
verts[v].fKLM[0] = eval_line(verts[v].fPosition, klmEqs + 0, klmSigns[c]);
verts[v].fKLM[1] = eval_line(verts[v].fPosition, klmEqs + 3, klmSigns[c]);
verts[v].fKLM[2] = eval_line(verts[v].fPosition, klmEqs + 6, 1.f);
}
GrTestTarget tt;
context->getTestTarget(&tt);
if (NULL == tt.target()) {
continue;
}
GrDrawState* drawState = tt.target()->drawState();
drawState->setVertexAttribs<kAttribs>(2);
SkAutoTUnref<GrEffectRef> effect(HairCubicEdgeEffect::Create());
if (!effect) {
continue;
}
drawState->addCoverageEffect(effect, 1);
drawState->setRenderTarget(rt);
drawState->setColor(0xff000000);
tt.target()->setVertexSourceToArray(verts, 4);
tt.target()->setIndexSourceToBuffer(context->getQuadIndexBuffer());
tt.target()->drawIndexed(kTriangleFan_GrPrimitiveType, 0, 0, 4, 6);
}
++col;
if (numCols == col) {
col = 0;
++row;
}
}
}
private:
typedef GM INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_GM( return SkNEW(BezierEffects); )
}
#endif
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