49 lines
1.7 KiB
C++
49 lines
1.7 KiB
C++
// Copyright 2020 Google LLC.
|
|
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
|
|
#include "tools/fiddle/examples.h"
|
|
REG_FIDDLE(GradientShader_MakeLinear, 201, 201, false, 0) {
|
|
void draw(SkCanvas* canvas) {
|
|
// This fiddle draws 4 instances of a LinearGradient, demonstrating
|
|
// how the local matrix affects the gradient as well as the flag
|
|
// which controls unpremul vs premul color interpolation.
|
|
|
|
SkPaint strokePaint;
|
|
strokePaint.setStyle(SkPaint::kStroke_Style);
|
|
strokePaint.setColor(SK_ColorBLACK);
|
|
|
|
SkPaint p;
|
|
p.setStyle(SkPaint::kFill_Style);
|
|
|
|
SkColor transparentGreen = SkColorSetARGB(0, 0, 255, 255);
|
|
SkColor colors[] = { transparentGreen, SK_ColorBLUE, SK_ColorRED };
|
|
SkScalar positions[] = { 0.0, 0.65, 1.0 };
|
|
|
|
for (int i = 0; i < 4; i++) {
|
|
SkScalar blockX = (i % 2) * 100;
|
|
SkScalar blockY = (i / 2) * 100;
|
|
SkPoint pts[] = { {blockX, blockY}, {blockX + 50, blockY + 100} };
|
|
|
|
int flags = 0; // interpolate colors in unpremul
|
|
if (i % 2 == 1) {
|
|
// right column will have premul
|
|
flags = SkGradientShader::Flags::kInterpolateColorsInPremul_Flag;
|
|
}
|
|
|
|
SkMatrix matr = SkMatrix::I();
|
|
if (i / 2 == 1) {
|
|
// bottom row will be rotated 45 degrees.
|
|
matr.setRotate(45, blockX, blockY);
|
|
}
|
|
|
|
auto lgs = SkGradientShader::MakeLinear(
|
|
pts, colors, positions, 3, SkTileMode::kMirror,
|
|
flags, &matr);
|
|
|
|
p.setShader(lgs);
|
|
auto r = SkRect::MakeLTRB(blockX, blockY, blockX + 100, blockY + 100);
|
|
canvas->drawRect(r, p);
|
|
canvas->drawRect(r, strokePaint);
|
|
}
|
|
}
|
|
} // END FIDDLE
|