skia2/gm/drawimageset.cpp

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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.h"
#include <algorithm>
#include "SkGradientShader.h"
#include "SkSurface.h"
#include "ToolUtils.h"
// Makes a set of m x n tiled images to be drawn with SkCanvas::experimental_drawImageSetV1().
static void make_image_tiles(int tileW, int tileH, int m, int n, const SkColor colors[4],
SkCanvas::ImageSetEntry set[]) {
const int w = tileW * m;
const int h = tileH * n;
auto surf = SkSurface::MakeRaster(
SkImageInfo::Make(w, h, kRGBA_8888_SkColorType, kPremul_SkAlphaType));
surf->getCanvas()->clear(SK_ColorLTGRAY);
static constexpr SkScalar kStripeW = 10;
static constexpr SkScalar kStripeSpacing = 30;
SkPaint paint;
SkPoint pts1[] = {{0.f, 0.f}, {(SkScalar)w, (SkScalar)h}};
auto grad = SkGradientShader::MakeLinear(pts1, colors, nullptr, 2, SkShader::kClamp_TileMode);
paint.setShader(std::move(grad));
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(kStripeW);
SkPoint stripePts[] = {{-w - kStripeW, -kStripeW}, {kStripeW, h + kStripeW}};
while (stripePts[0].fX <= w) {
surf->getCanvas()->drawPoints(SkCanvas::kLines_PointMode, 2, stripePts, paint);
stripePts[0].fX += kStripeSpacing;
stripePts[1].fX += kStripeSpacing;
}
SkPoint pts2[] = {{0.f, (SkScalar)h}, {(SkScalar)w, 0.f}};
grad = SkGradientShader::MakeLinear(pts2, colors + 2, nullptr, 2, SkShader::kClamp_TileMode);
paint.setShader(std::move(grad));
paint.setBlendMode(SkBlendMode::kMultiply);
stripePts[0] = {-w - kStripeW, h + kStripeW};
stripePts[1] = {kStripeW, -kStripeW};
while (stripePts[0].fX <= w) {
surf->getCanvas()->drawPoints(SkCanvas::kLines_PointMode, 2, stripePts, paint);
stripePts[0].fX += kStripeSpacing;
stripePts[1].fX += kStripeSpacing;
}
auto fullImage = surf->makeImageSnapshot();
for (int y = 0; y < n; ++y) {
for (int x = 0; x < m; ++x) {
// Images will have 1 pixel of overlap at interior seams for filtering continuity.
SkIRect subset = SkIRect::MakeXYWH(x * tileW - 1, y * tileH - 1, tileW + 2, tileH + 2);
set[y * m + x].fAAFlags = SkCanvas::kNone_QuadAAFlags;
if (x == 0) {
subset.fLeft = 0;
set[y * m + x].fAAFlags |= SkCanvas::kLeft_QuadAAFlag;
}
if (x == m - 1) {
subset.fRight = w;
set[y * m + x].fAAFlags |= SkCanvas::kRight_QuadAAFlag;
}
if (y == 0) {
subset.fTop = 0;
set[y * m + x].fAAFlags |= SkCanvas::kTop_QuadAAFlag;
}
if (y == n - 1) {
subset.fBottom = h;
set[y * m + x].fAAFlags |= SkCanvas::kBottom_QuadAAFlag;
}
set[y * m + x].fImage = fullImage->makeSubset(subset);
set[y * m + x].fSrcRect =
SkRect::MakeXYWH(x == 0 ? 0 : 1, y == 0 ? 0 : 1, tileW, tileH);
set[y * m + x].fDstRect = SkRect::MakeXYWH(x * tileW, y * tileH, tileW, tileH);
set[y * m + x].fAlpha = 1.f;
SkASSERT(set[y * m + x].fImage);
}
}
}
namespace skiagm {
class DrawImageSetGM : public GM {
private:
SkString onShortName() final { return SkString("draw_image_set"); }
SkISize onISize() override { return SkISize::Make(1000, 725); }
void onOnceBeforeDraw() override {
static constexpr SkColor kColors[] = {SK_ColorCYAN, SK_ColorBLACK,
SK_ColorMAGENTA, SK_ColorBLACK};
make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet);
}
void onDraw(SkCanvas* canvas) override {
SkScalar d = SkVector{kM * kTileW, kN * kTileH}.length();
SkMatrix matrices[4];
// rotation
matrices[0].setRotate(30);
matrices[0].postTranslate(d / 3, 0);
// perespective
SkPoint src[4];
SkRect::MakeWH(kM * kTileW, kN * kTileH).toQuad(src);
SkPoint dst[4] = {{0, 0},
{kM * kTileW + 10.f, -5.f},
{kM * kTileW - 28.f, kN * kTileH + 40.f},
{45.f, kN * kTileH - 25.f}};
SkAssertResult(matrices[1].setPolyToPoly(src, dst, 4));
matrices[1].postTranslate(d, 50.f);
// skew
matrices[2].setRotate(-60.f);
matrices[2].postSkew(0.5f, -1.15f);
matrices[2].postScale(0.6f, 1.05f);
matrices[2].postTranslate(d, 2.6f * d);
// perspective + mirror in x.
dst[1] = {-.25 * kM * kTileW, 0};
dst[0] = {5.f / 4.f * kM * kTileW, 0};
dst[3] = {2.f / 3.f * kM * kTileW, 1 / 2.f * kN * kTileH};
dst[2] = {1.f / 3.f * kM * kTileW, 1 / 2.f * kN * kTileH - 0.1f * kTileH};
SkAssertResult(matrices[3].setPolyToPoly(src, dst, 4));
matrices[3].postTranslate(100.f, d);
for (auto fm : {kNone_SkFilterQuality, kLow_SkFilterQuality}) {
for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
// Draw grid of red lines at interior tile boundaries.
static constexpr SkScalar kLineOutset = 10.f;
SkPaint paint;
paint.setAntiAlias(true);
paint.setColor(SK_ColorRED);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(0.f);
for (int x = 1; x < kM; ++x) {
SkPoint pts[] = {{x * kTileW, 0}, {x * kTileW, kN * kTileH}};
matrices[m].mapPoints(pts, 2);
SkVector v = pts[1] - pts[0];
v.setLength(v.length() + kLineOutset);
canvas->drawLine(pts[1] - v, pts[0] + v, paint);
}
for (int y = 1; y < kN; ++y) {
SkPoint pts[] = {{0, y * kTileH}, {kTileW * kM, y * kTileH}};
matrices[m].mapPoints(pts, 2);
SkVector v = pts[1] - pts[0];
v.setLength(v.length() + kLineOutset);
canvas->drawLine(pts[1] - v, pts[0] + v, paint);
}
canvas->save();
canvas->concat(matrices[m]);
canvas->experimental_DrawImageSetV1(fSet, kM * kN, fm, SkBlendMode::kSrcOver);
canvas->restore();
}
// A more exotic case with an unusual blend mode, mixed aa flags set, and alpha,
// subsets the image
SkCanvas::ImageSetEntry entry;
entry.fSrcRect = SkRect::MakeWH(kTileW, kTileH).makeInset(kTileW / 4.f, kTileH / 4.f);
entry.fDstRect = SkRect::MakeWH(2 * kTileW, 2 * kTileH).makeOffset(d / 4, 2 * d);
entry.fImage = fSet[0].fImage;
entry.fAlpha = 0.7f;
entry.fAAFlags = SkCanvas::kLeft_QuadAAFlag | SkCanvas::kTop_QuadAAFlag;
canvas->save();
canvas->rotate(3.f);
canvas->experimental_DrawImageSetV1(&entry, 1, fm, SkBlendMode::kExclusion);
canvas->restore();
canvas->translate(2 * d, 0);
}
}
static constexpr int kM = 4;
static constexpr int kN = 3;
static constexpr SkScalar kTileW = 30;
static constexpr SkScalar kTileH = 60;
SkCanvas::ImageSetEntry fSet[kM * kN];
};
// This GM exercises rect-stays-rect type matrices to test that filtering and antialiasing are not
// incorrectly disabled.
class DrawImageSetRectToRectGM : public GM {
private:
SkString onShortName() final { return SkString("draw_image_set_rect_to_rect"); }
SkISize onISize() override { return SkISize::Make(1250, 850); }
void onOnceBeforeDraw() override {
static constexpr SkColor kColors[] = {SK_ColorBLUE, SK_ColorWHITE,
SK_ColorRED, SK_ColorWHITE};
make_image_tiles(kTileW, kTileH, kM, kN, kColors, fSet);
}
void onDraw(SkCanvas* canvas) override {
ToolUtils::draw_checkerboard(canvas, SK_ColorBLACK, SK_ColorWHITE, 50);
static constexpr SkScalar kW = kM * kTileW;
static constexpr SkScalar kH = kN * kTileH;
SkMatrix matrices[5];
// Identity
matrices[0].reset();
// 90 degree rotation
matrices[1].setRotate(90, kW / 2.f, kH / 2.f);
// Scaling
matrices[2].setScale(2.f, 0.5f);
// Mirror in x and y
matrices[3].setScale(-1.f, -1.f);
matrices[3].postTranslate(kW, kH);
// Mirror in y, rotate, and scale.
matrices[4].setScale(1.f, -1.f);
matrices[4].postTranslate(0, kH);
matrices[4].postRotate(90, kW / 2.f, kH / 2.f);
matrices[4].postScale(2.f, 0.5f);
static constexpr SkScalar kTranslate = SkTMax(kW, kH) * 2.f + 10.f;
canvas->translate(5.f, 5.f);
canvas->save();
for (SkScalar frac : {0.f, 0.5f}) {
canvas->save();
canvas->translate(frac, frac);
for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
canvas->save();
canvas->concat(matrices[m]);
canvas->experimental_DrawImageSetV1(fSet, kM * kN, kLow_SkFilterQuality,
SkBlendMode::kSrcOver);
canvas->restore();
canvas->translate(kTranslate, 0);
}
canvas->restore();
canvas->restore();
canvas->translate(0, kTranslate);
canvas->save();
}
for (SkVector scale : {SkVector{2.f, 0.5f}, SkVector{0.5, 2.f}}) {
SkCanvas::ImageSetEntry scaledSet[kM * kN];
std::copy_n(fSet, kM * kN, scaledSet);
for (int i = 0; i < kM * kN; ++i) {
scaledSet[i].fDstRect.fLeft *= scale.fX;
scaledSet[i].fDstRect.fTop *= scale.fY;
scaledSet[i].fDstRect.fRight *= scale.fX;
scaledSet[i].fDstRect.fBottom *= scale.fY;
scaledSet[i].fAlpha = 0 == (i % 3) ? 0.4f : 1.f;
}
for (size_t m = 0; m < SK_ARRAY_COUNT(matrices); ++m) {
canvas->save();
canvas->concat(matrices[m]);
canvas->experimental_DrawImageSetV1(scaledSet, kM * kN, kLow_SkFilterQuality,
SkBlendMode::kSrcOver);
canvas->restore();
canvas->translate(kTranslate, 0);
}
canvas->restore();
canvas->translate(0, kTranslate);
canvas->save();
}
}
static constexpr int kM = 2;
static constexpr int kN = 2;
static constexpr int kTileW = 40;
static constexpr int kTileH = 50;
SkCanvas::ImageSetEntry fSet[kM * kN];
};
DEF_GM(return new DrawImageSetGM();)
DEF_GM(return new DrawImageSetRectToRectGM();)
} // namespace skiagm