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/*
* 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/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPath.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTypes.h"
#include "include/gpu/GrContextOptions.h"
#include "include/gpu/GrRecordingContext.h"
#include "src/core/SkGeometry.h"
#include "src/gpu/GrDrawingManager.h"
#include "src/gpu/GrRecordingContextPriv.h"
#include "src/gpu/tessellate/GrTessellationPathRenderer.h"
static constexpr float kStrokeWidth = 30;
static constexpr int kCellSize = 200;
static constexpr int kNumCols = 5;
static constexpr int kNumRows = 5;
static constexpr int kTestWidth = kNumCols * kCellSize;
static constexpr int kTestHeight = kNumRows * kCellSize;
enum class CellFillMode {
kStretch,
kCenter
};
struct TrickyCubic {
SkPoint fPoints[4];
int fNumPts;
CellFillMode fFillMode;
float fScale = 1;
};
// This is a compilation of cubics that have given strokers grief. Feel free to add more.
static const TrickyCubic kTrickyCubics[] = {
{{{122, 737}, {348, 553}, {403, 761}, {400, 760}}, 4, CellFillMode::kStretch},
{{{244, 520}, {244, 518}, {1141, 634}, {394, 688}}, 4, CellFillMode::kStretch},
{{{550, 194}, {138, 130}, {1035, 246}, {288, 300}}, 4, CellFillMode::kStretch},
{{{226, 733}, {556, 779}, {-43, 471}, {348, 683}}, 4, CellFillMode::kStretch},
{{{268, 204}, {492, 304}, {352, 23}, {433, 412}}, 4, CellFillMode::kStretch},
{{{172, 480}, {396, 580}, {256, 299}, {338, 677}}, 4, CellFillMode::kStretch},
{{{731, 340}, {318, 252}, {1026, -64}, {367, 265}}, 4, CellFillMode::kStretch},
{{{475, 708}, {62, 620}, {770, 304}, {220, 659}}, 4, CellFillMode::kStretch},
{{{0, 0}, {128, 128}, {128, 0}, {0, 128}}, 4, CellFillMode::kCenter}, // Perfect cusp
{{{0,.01f}, {128,127.999f}, {128,.01f}, {0,127.99f}}, 4, CellFillMode::kCenter}, // Near-cusp
{{{0,-.01f}, {128,128.001f}, {128,-.01f}, {0,128.001f}}, 4, CellFillMode::kCenter}, // Near-cusp
{{{0,0}, {0,-10}, {0,-10}, {0,10}}, 4, CellFillMode::kCenter, 1.098283f}, // Flat line with 180
{{{10,0}, {0,0}, {20,0}, {10,0}}, 4, CellFillMode::kStretch}, // Flat line with 2 180s
{{{39,-39}, {40,-40}, {40,-40}, {0,0}}, 4, CellFillMode::kStretch}, // Flat diagonal with 180
{{{40, 40}, {0, 0}, {200, 200}, {0, 0}}, 4, CellFillMode::kStretch}, // Diag w/ an internal 180
{{{0,0}, {1e-2f,0}, {-1e-2f,0}, {0,0}}, 4, CellFillMode::kCenter}, // Circle
{{{400.75f,100.05f}, {400.75f,100.05f}, {100.05f,300.95f}, {100.05f,300.95f}}, 4,
CellFillMode::kStretch}, // Flat line with no turns
{{{0.5f,0}, {0,0}, {20,0}, {10,0}}, 4, CellFillMode::kStretch}, // Flat line with 2 180s
{{{10,0}, {0,0}, {10,0}, {10,0}}, 4, CellFillMode::kStretch}, // Flat line with a 180
{{{1,1}, {2,1}, {1,1}, {1, std::numeric_limits<float>::quiet_NaN()}}, 3,
CellFillMode::kStretch}, // Flat QUAD with a cusp
{{{1,1}, {100,1}, {25,1}, {.3f, std::numeric_limits<float>::quiet_NaN()}}, 3,
CellFillMode::kStretch}, // Flat CONIC with a cusp
{{{1,1}, {100,1}, {25,1}, {1.5f, std::numeric_limits<float>::quiet_NaN()}}, 3,
CellFillMode::kStretch}, // Flat CONIC with a cusp
};
static SkRect calc_tight_cubic_bounds(const SkPoint P[4], int depth=5) {
if (0 == depth) {
SkRect bounds;
bounds.fLeft = std::min(std::min(P[0].x(), P[1].x()), std::min(P[2].x(), P[3].x()));
bounds.fTop = std::min(std::min(P[0].y(), P[1].y()), std::min(P[2].y(), P[3].y()));
bounds.fRight = std::max(std::max(P[0].x(), P[1].x()), std::max(P[2].x(), P[3].x()));
bounds.fBottom = std::max(std::max(P[0].y(), P[1].y()), std::max(P[2].y(), P[3].y()));
return bounds;
}
SkPoint chopped[7];
SkChopCubicAt(P, chopped, .5f);
SkRect bounds = calc_tight_cubic_bounds(chopped, depth - 1);
bounds.join(calc_tight_cubic_bounds(chopped+3, depth - 1));
return bounds;
}
static SkPoint lerp(const SkPoint& a, const SkPoint& b, float T) {
SkASSERT(1 != T); // The below does not guarantee lerp(a, b, 1) === b.
return (b - a) * T + a;
}
enum class FillMode {
kCenter,
kScale
};
static void draw_test(SkCanvas* canvas, SkPaint::Cap cap, SkPaint::Join join) {
SkRandom rand;
if (canvas->recordingContext() &&
canvas->recordingContext()->priv().caps()->shaderCaps()->tessellationSupport() &&
canvas->recordingContext()->priv().caps()->shaderCaps()->maxTessellationSegments() < 64) {
// There are fewer tessellation segments than the spec minimum. It must have been overriden
// for testing. Indicate this in the background color.
canvas->clear(SkColorSetARGB(255, 64, 0, 0));
} else {
canvas->clear(SK_ColorBLACK);
}
SkPaint strokePaint;
strokePaint.setAntiAlias(true);
strokePaint.setStrokeWidth(kStrokeWidth);
strokePaint.setStyle(SkPaint::kStroke_Style);
strokePaint.setStrokeCap(cap);
strokePaint.setStrokeJoin(join);
for (size_t i = 0; i < SK_ARRAY_COUNT(kTrickyCubics); ++i) {
auto [originalPts, numPts, fillMode, scale] = kTrickyCubics[i];
SkASSERT(numPts <= 4);
SkPoint p[4];
memcpy(p, originalPts, sizeof(SkPoint) * numPts);
for (int j = 0; j < numPts; ++j) {
p[j] *= scale;
}
float w = originalPts[3].fX;
auto cellRect = SkRect::MakeXYWH((i % kNumCols) * kCellSize, (i / kNumCols) * kCellSize,
kCellSize, kCellSize);
SkRect strokeBounds;
if (numPts == 4) {
strokeBounds = calc_tight_cubic_bounds(p);
} else {
SkASSERT(numPts == 3);
SkPoint asCubic[4] = {p[0], lerp(p[0], p[1], 2/3.f), lerp(p[1], p[2], 1/3.f), p[2]};
strokeBounds = calc_tight_cubic_bounds(asCubic);
}
strokeBounds.outset(kStrokeWidth, kStrokeWidth);
SkMatrix matrix;
if (fillMode == CellFillMode::kStretch) {
matrix = SkMatrix::RectToRect(strokeBounds, cellRect, SkMatrix::kCenter_ScaleToFit);
} else {
matrix.setTranslate(cellRect.x() + kStrokeWidth +
(cellRect.width() - strokeBounds.width()) / 2,
cellRect.y() + kStrokeWidth +
(cellRect.height() - strokeBounds.height()) / 2);
}
SkAutoCanvasRestore acr(canvas, true);
canvas->concat(matrix);
strokePaint.setStrokeWidth(kStrokeWidth / matrix.getMaxScale());
strokePaint.setColor(rand.nextU() | 0xff808080);
SkPath path = SkPath().moveTo(p[0]);
if (numPts == 4) {
path.cubicTo(p[1], p[2], p[3]);
} else if (w == 1) {
SkASSERT(numPts == 3);
path.quadTo(p[1], p[2]);
} else {
SkASSERT(numPts == 3);
path.conicTo(p[1], p[2], w);
}
canvas->drawPath(path, strokePaint);
}
}
DEF_SIMPLE_GM(trickycubicstrokes, canvas, kTestWidth, kTestHeight) {
draw_test(canvas, SkPaint::kButt_Cap, SkPaint::kMiter_Join);
}
DEF_SIMPLE_GM(trickycubicstrokes_roundcaps, canvas, kTestWidth, kTestHeight) {
draw_test(canvas, SkPaint::kRound_Cap, SkPaint::kRound_Join);
}
class TrickyCubicStrokes_tess_segs_5 : public skiagm::GpuGM {
SkString onShortName() override {
return SkString("trickycubicstrokes_tess_segs_5");
}
SkISize onISize() override {
return SkISize::Make(kTestWidth, kTestHeight);
}
// Pick a very small, odd (and better yet, prime) number of segments.
//
// - Odd because it makes the tessellation strip asymmetric, which will be important to test for
// future plans that involve drawing in reverse order.
//
// - >=4 because the tessellator code will just assume we have enough to combine a miter join
// and line in a single patch. (Requires 4 segments. Spec required minimum is 64.)
static constexpr int kMaxTessellationSegmentsOverride = 5;
void modifyGrContextOptions(GrContextOptions* options) override {
options->fMaxTessellationSegmentsOverride = kMaxTessellationSegmentsOverride;
// Only allow the tessellation path renderer.
options->fGpuPathRenderers = (GpuPathRenderers)((int)options->fGpuPathRenderers &
(int)GpuPathRenderers::kTessellation);
}
DrawResult onDraw(GrRecordingContext* context, GrSurfaceDrawContext*, SkCanvas* canvas,
SkString* errorMsg) override {
if (!context->priv().caps()->shaderCaps()->tessellationSupport() ||
!GrTessellationPathRenderer::IsSupported(*context->priv().caps())) {
errorMsg->set("Tessellation not supported.");
return DrawResult::kSkip;
}
auto opts = context->priv().drawingManager()->testingOnly_getOptionsForPathRendererChain();
if (!(opts.fGpuPathRenderers & GpuPathRenderers::kTessellation)) {
errorMsg->set("GrTessellationPathRenderer disabled.");
return DrawResult::kSkip;
}
if (context->priv().caps()->shaderCaps()->maxTessellationSegments() !=
kMaxTessellationSegmentsOverride) {
errorMsg->set("modifyGrContextOptions did not affect maxTessellationSegments. "
"(Are you running viewer? If so use '--maxTessellationSegments 5'.)");
return DrawResult::kFail;
}
// Suppress a tessellator warning message that caps.maxTessellationSegments is too small.
GrRecordingContextPriv::AutoSuppressWarningMessages aswm(context);
draw_test(canvas, SkPaint::kButt_Cap, SkPaint::kMiter_Join);
return DrawResult::kOk;
}
};
DEF_GM( return new TrickyCubicStrokes_tess_segs_5; )