skia2/gm/transparency.cpp
Ben Wagner 7fde8e1728 IWYU for gms.
This almost gets gms to be iwyu clean. The last bit is around gm.cpp
and the tracing framework and its use of atomic. Will also need a way
of keeping things from regressing, which is difficult due to needing to
do this outside-in.

Change-Id: I1393531e99da8b0f1a29f55c53c86d53f459af7d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/211593
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
2019-05-02 17:48:53 +00:00

80 lines
2.6 KiB
C++

/*
* Copyright 2015 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/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkSurface.h"
#include "include/core/SkTileMode.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkGradientShader.h"
static void make_transparency(SkCanvas* canvas, SkScalar width, SkScalar height) {
SkPoint pts[2];
pts[0] = SkPoint::Make(0, 0);
pts[1] = SkPoint::Make(width, 0);
const SkColor kColors[] = {
SK_ColorBLACK,
SK_ColorGRAY,
SK_ColorWHITE,
SK_ColorRED,
SK_ColorYELLOW,
SK_ColorGREEN,
SK_ColorCYAN,
SK_ColorBLUE,
SK_ColorMAGENTA,
};
const SkScalar kRowHeight = height / SK_ARRAY_COUNT(kColors);
for (size_t i = 0; i < SK_ARRAY_COUNT(kColors); ++i) {
SkColor shaderColors[2];
shaderColors[0] = SK_AlphaTRANSPARENT;
shaderColors[1] = kColors[i];
SkPaint p;
p.setShader(SkGradientShader::MakeLinear(pts, shaderColors, nullptr, 2, SkTileMode::kClamp));
canvas->drawRect(SkRect::MakeXYWH(0, i * kRowHeight, width, kRowHeight), p);
}
}
// http://crrev.com/834303005
static sk_sp<SkShader> create_checkerboard_shader(SkColor c1, SkColor c2, int size) {
SkBitmap bm;
bm.allocN32Pixels(2 * size, 2 * size);
bm.eraseColor(c1);
bm.eraseArea(SkIRect::MakeLTRB(0, 0, size, size), c2);
bm.eraseArea(SkIRect::MakeLTRB(size, size, 2 * size, 2 * size), c2);
return bm.makeShader(SkTileMode::kRepeat, SkTileMode::kRepeat);
}
// http://crrev.com/834303005
static void checkerboard(SkCanvas* canvas, SkColor c1, SkColor c2, int size) {
SkPaint paint;
paint.setShader(create_checkerboard_shader(c1, c2, size));
canvas->drawPaint(paint);
}
/**
* This GM verifies that a transparent bitmap drawn over a
* checkerboard pattern looks correct.
*/
DEF_SIMPLE_GM(transparency_check, canvas, 1792, 1080) {
checkerboard(canvas, 0xFF999999, 0xFF666666, 8);
{
SkAutoCanvasRestore autoCanvasRestore(canvas, true);
auto surface(SkSurface::MakeRasterN32Premul(256, 9));
make_transparency(surface->getCanvas(), 256.0f, 9.0f);
canvas->scale(7.0f, 120.0f);
surface->draw(canvas, 0, 0, nullptr);
}
}