| /* |
| * Copyright 2013 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/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/SkTileMode.h" |
| #include "include/core/SkTypes.h" |
| #include "include/effects/SkGradientShader.h" |
| |
| constexpr SkColor gColors[] = { |
| SK_ColorRED, SK_ColorYELLOW |
| }; |
| |
| // These annoying defines are necessary, because the only other alternative |
| // is to use SkIntToScalar(...) everywhere. |
| constexpr SkScalar sZero = 0; |
| constexpr SkScalar sHalf = SK_ScalarHalf; |
| constexpr SkScalar sOne = SK_Scalar1; |
| |
| // These arrays define the gradient stop points |
| // as x1, y1, x2, y2 per gradient to draw. |
| constexpr SkPoint linearPts[][2] = { |
| {{sZero, sZero}, {sOne, sZero}}, |
| {{sZero, sZero}, {sZero, sOne}}, |
| {{sOne, sZero}, {sZero, sZero}}, |
| {{sZero, sOne}, {sZero, sZero}}, |
| |
| {{sZero, sZero}, {sOne, sOne}}, |
| {{sOne, sOne}, {sZero, sZero}}, |
| {{sOne, sZero}, {sZero, sOne}}, |
| {{sZero, sOne}, {sOne, sZero}} |
| }; |
| |
| constexpr SkPoint radialPts[][2] = { |
| {{sZero, sHalf}, {sOne, sHalf}}, |
| {{sHalf, sZero}, {sHalf, sOne}}, |
| {{sOne, sHalf}, {sZero, sHalf}}, |
| {{sHalf, sOne}, {sHalf, sZero}}, |
| |
| {{sZero, sZero}, {sOne, sOne}}, |
| {{sOne, sOne}, {sZero, sZero}}, |
| {{sOne, sZero}, {sZero, sOne}}, |
| {{sZero, sOne}, {sOne, sZero}} |
| }; |
| |
| // These define the pixels allocated to each gradient image. |
| constexpr SkScalar TESTGRID_X = SkIntToScalar(200); |
| constexpr SkScalar TESTGRID_Y = SkIntToScalar(200); |
| |
| constexpr int IMAGES_X = 4; // number of images per row |
| |
| static sk_sp<SkShader> make_linear_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) { |
| return SkGradientShader::MakeLinear(pts, gColors, nullptr, std::size(gColors), |
| SkTileMode::kClamp, 0, &localMatrix); |
| } |
| |
| static sk_sp<SkShader> make_radial_gradient(const SkPoint pts[2], const SkMatrix& localMatrix) { |
| SkPoint center; |
| center.set(SkScalarAve(pts[0].fX, pts[1].fX), |
| SkScalarAve(pts[0].fY, pts[1].fY)); |
| float radius = (center - pts[0]).length(); |
| return SkGradientShader::MakeRadial(center, radius, gColors, nullptr, std::size(gColors), |
| SkTileMode::kClamp, 0, &localMatrix); |
| } |
| |
| static void draw_gradients(SkCanvas* canvas, |
| sk_sp<SkShader> (*makeShader)(const SkPoint[2], const SkMatrix&), |
| const SkPoint ptsArray[][2], int numImages) { |
| // Use some nice prime numbers for the rectangle and matrix with |
| // different scaling along the x and y axes (which is the bug this |
| // test addresses, where incorrect order of operations mixed up the axes) |
| SkRect rectGrad = { |
| SkIntToScalar(43), SkIntToScalar(61), |
| SkIntToScalar(181), SkIntToScalar(167) }; |
| SkMatrix shaderMat; |
| shaderMat.setScale(rectGrad.width(), rectGrad.height()); |
| shaderMat.postTranslate(rectGrad.left(), rectGrad.top()); |
| |
| canvas->save(); |
| for (int i = 0; i < numImages; i++) { |
| // Advance line downwards if necessary. |
| if (i % IMAGES_X == 0 && i != 0) { |
| canvas->restore(); |
| canvas->translate(0, TESTGRID_Y); |
| canvas->save(); |
| } |
| |
| SkPaint paint; |
| paint.setShader(makeShader(*ptsArray, shaderMat)); |
| canvas->drawRect(rectGrad, paint); |
| |
| // Advance to next position. |
| canvas->translate(TESTGRID_X, 0); |
| ptsArray++; |
| } |
| canvas->restore(); |
| } |
| |
| DEF_SIMPLE_GM_BG(gradient_matrix, canvas, 800, 800, 0xFFDDDDDD) { |
| draw_gradients(canvas, &make_linear_gradient, |
| linearPts, std::size(linearPts)); |
| |
| canvas->translate(0, TESTGRID_Y); |
| |
| draw_gradients(canvas, &make_radial_gradient, |
| radialPts, std::size(radialPts)); |
| } |