blob: 6785f9fdd205b4b94e19a9b52abee1accfadd2b6 [file] [log] [blame]
/*
* Copyright 2019 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/SkFilterQuality.h"
#include "include/core/SkFont.h"
#include "include/core/SkFontTypes.h"
#include "include/core/SkImage.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkMatrix44.h"
#include "include/core/SkPaint.h"
#include "include/core/SkRRect.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkSurface.h"
#include "tools/timer/TimeUtils.h"
// Mimics https://output.jsbin.com/falefice/1/quiet?CC_POSTER_CIRCLE, which can't be captured as
// an SKP due to many 3D layers being composited post-SKP capture.
// See skbug.com/9028
class PosterCircleGM : public skiagm::GM {
public:
PosterCircleGM() : fTime(0.f) {}
protected:
SkString onShortName() override {
return SkString("poster_circle");
}
SkISize onISize() override {
return SkISize::Make(kStageWidth, kStageHeight + 50);
}
bool onAnimate(double nanos) override {
fTime = TimeUtils::Scaled(1e-9 * nanos, 0.5f);
return true;
}
void onOnceBeforeDraw() override {
SkFont font;
font.setEdging(SkFont::Edging::kAntiAlias);
font.setEmbolden(true);
font.setSize(24.f);
sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(kPosterSize, kPosterSize);
for (int i = 0; i < kNumAngles; ++i) {
SkCanvas* canvas = surface->getCanvas();
SkPaint fillPaint;
fillPaint.setAntiAlias(true);
fillPaint.setColor(i % 2 == 0 ? SkColorSetRGB(0x99, 0x5C, 0x7F)
: SkColorSetRGB(0x83, 0x5A, 0x99));
canvas->drawRRect(SkRRect::MakeRectXY(SkRect::MakeWH(kPosterSize, kPosterSize),
10.f, 10.f), fillPaint);
SkString label;
label.printf("%d", i);
SkRect labelBounds;
font.measureText(label.c_str(), label.size(), SkTextEncoding::kUTF8, &labelBounds);
SkScalar labelX = 0.5f * kPosterSize - 0.5f * labelBounds.width();
SkScalar labelY = 0.5f * kPosterSize + 0.5f * labelBounds.height();
SkPaint labelPaint;
labelPaint.setAntiAlias(true);
canvas->drawString(label, labelX, labelY, font, labelPaint);
fPosterImages[i] = surface->makeImageSnapshot();
}
}
void onDraw(SkCanvas* canvas) override {
// See https://developer.mozilla.org/en-US/docs/Web/CSS/transform-function/perspective
// for projection matrix when --webkit-perspective: 800px is used.
SkMatrix44 proj(SkMatrix44::kIdentity_Constructor);
proj.set(3, 2, -1.f / 800.f);
for (int pass = 0; pass < 2; ++pass) {
// Want to draw 90 to 270 first (the back), then 270 to 90 (the front), but do all 3
// rings backsides, then their frontsides since the front projections overlap across
// rings. Note: we skip the poster circle's x axis rotation because that complicates the
// back-to-front drawing order and it isn't necessary to trigger draws aligned with Z.
bool drawFront = pass > 0;
for (int y = 0; y < 3; ++y) {
float ringY = (y - 1) * (kPosterSize + 10.f);
for (int i = 0; i < kNumAngles; ++i) {
// Add an extra 45 degree rotation, which triggers the bug by aligning some of
// the posters with the z axis.
SkScalar yDuration = 5.f - y;
SkScalar yRotation = SkScalarMod(kAngleStep * i +
360.f * SkScalarMod(fTime / yDuration, yDuration), 360.f);
// These rotation limits were chosen manually to line up with current projection
static constexpr SkScalar kBackMinAngle = 70.f;
static constexpr SkScalar kBackMaxAngle = 290.f;
if (drawFront) {
if (yRotation >= kBackMinAngle && yRotation <= kBackMaxAngle) {
// Back portion during a front draw
continue;
}
} else {
if (yRotation < kBackMinAngle || yRotation > kBackMaxAngle) {
// Front portion during a back draw
continue;
}
}
canvas->save();
// Matrix matches transform: rotateY(<angle>deg) translateZ(200px); nested in an
// element with the perspective projection matrix above.
SkMatrix44 model;
// No post/preRotate, so start with rotation matrix and adjust from there
model.setRotateAboutUnit(0.f, 1.f, 0.f, SkDegreesToRadians(yRotation));
model.preTranslate(0.f, 0.f, kRingRadius); // *before* rotation
model.postTranslate(0.f, ringY, 0.f); // *after* rotation
model.postConcat(proj);
model.postTranslate(0.5f * kStageWidth, 0.5f * kStageHeight + 25, 0.f);
// Flatten the 4x4 matrix by discarding the 3rd row and column
canvas->concat(SkMatrix::MakeAll(
model.get(0, 0), model.get(0, 1), model.get(0, 3),
model.get(1, 0), model.get(1, 1), model.get(1, 3),
model.get(3, 0), model.get(3, 1), model.get(3, 3)));
SkRect poster = SkRect::MakeLTRB(-0.5f * kPosterSize, -0.5f * kPosterSize,
0.5f * kPosterSize, 0.5f * kPosterSize);
SkPaint fillPaint;
fillPaint.setAntiAlias(true);
fillPaint.setAlphaf(0.7f);
fillPaint.setFilterQuality(kLow_SkFilterQuality);
canvas->drawImageRect(fPosterImages[i], poster, &fillPaint);
canvas->restore();
}
}
}
}
private:
static const int kAngleStep = 30;
static const int kNumAngles = 12; // 0 through 330 degrees
static const int kStageWidth = 600;
static const int kStageHeight = 400;
static const int kRingRadius = 200;
static const int kPosterSize = 100;
sk_sp<SkImage> fPosterImages[kNumAngles];
SkScalar fTime;
};
DEF_GM(return new PosterCircleGM();)