/* * 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 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 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 (*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)); }