/* * Copyright 2016 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ /* * This GM presents a variety of different gradients with different * tile modes. Each entry in the table is a rectangle with a linear * gradient that spans from its left edge to its right edge. The rows * in the table represent different color/position configurations, * while the columns in the table represent different tile modes. In * order to highlight the differences between tile modes, the gradient * starts and ends at 30 pixel inset from either side of the rectangle. * * | Clamp Repeat Mirror * _____________________________|___________________________________________ * 2-color | rect00 rect01 rect02 * 3-color even | rect10 rect11 rect12 * 3-color texture | rect20 rect21 rect22 * 5-color hard stop | rect30 rect31 rect32 * 4-color hard stop centered | rect40 rect41 rect42 * 3-color hard stop 001 | rect50 rect51 rect52 * 3-color hard stop 011 | rect60 rect61 rect62 * 4-color hard stop off-center | rect70 rect71 rect72 * * The first three rows are cases covered by pre-hard-stop code; simple * 2-color gradients, 3-color gradients with the middle color centered, * and general gradients that are rendered from a texture atlas. * * The next four rows all deal with hard stop gradients. The fourth row * is a generic hard stop gradient, while the three subsequent rows deal * with special cases of hard stop gradients; centered hard stop gradients * (with t-values 0, 0.5, 0.5, 1), and two edge cases (with t-values * 0, 0, 1 and 0, 1, 1). The final row has a single off-center hard stop. */ #include "gm/gm.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/SkSize.h" #include "include/core/SkString.h" #include "include/core/SkTileMode.h" #include "include/effects/SkGradientShader.h" const int WIDTH = 500; const int HEIGHT = 500; const int NUM_ROWS = 8; const int NUM_COLS = 3; const int CELL_WIDTH = WIDTH / NUM_COLS; const int CELL_HEIGHT = HEIGHT / NUM_ROWS; const int PAD_WIDTH = 3; const int PAD_HEIGHT = 3; const int RECT_WIDTH = CELL_WIDTH - (2 * PAD_WIDTH); const int RECT_HEIGHT = CELL_HEIGHT - (2 * PAD_HEIGHT); static void shade_rect(SkCanvas* canvas, sk_sp<SkShader> shader, int cellRow, int cellCol) { SkPaint paint; paint.setShader(shader); SkRect rect = SkRect::MakeXYWH(SkIntToScalar(cellCol * CELL_WIDTH + PAD_WIDTH), SkIntToScalar(cellRow * CELL_HEIGHT + PAD_HEIGHT), SkIntToScalar(RECT_WIDTH), SkIntToScalar(RECT_HEIGHT)); canvas->drawRect(rect, paint); } static void create_gradient_points(int cellRow, int cellCol, SkPoint points[2]) { const int X_OFFSET = 30; auto x0 = SkIntToScalar(cellCol * CELL_WIDTH + PAD_WIDTH + X_OFFSET); auto x1 = SkIntToScalar((cellCol+1) * CELL_WIDTH - PAD_WIDTH - X_OFFSET); auto y = SkIntToScalar(cellRow * CELL_HEIGHT + PAD_HEIGHT + RECT_HEIGHT/2); points[0] = SkPoint::Make(x0, y); points[1] = SkPoint::Make(x1, y); } class HardstopGradientShaderGM : public skiagm::GM { public: HardstopGradientShaderGM() { } protected: SkString onShortName() override { return SkString("hardstop_gradients"); } SkISize onISize() override { return SkISize::Make(512, 512); } void onDraw(SkCanvas* canvas) override { SkPoint points[2]; SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorYELLOW, SK_ColorMAGENTA, }; SkScalar row3[] = {0.00f, 0.25f, 1.00f}; SkScalar row4[] = {0.00f, 0.25f, 0.50f, 0.50f, 1.00f}; SkScalar row5[] = {0.00f, 0.50f, 0.50f, 1.00f}; SkScalar row6[] = {0.00f, 0.00f, 1.00f}; SkScalar row7[] = {0.00f, 1.00f, 1.00f}; SkScalar row8[] = {0.00f, 0.30f, 0.30f, 1.00f}; SkScalar* positions[NUM_ROWS] = { nullptr, nullptr, row3, row4, row5, row6, row7, row8, }; int numGradientColors[NUM_ROWS] = { 2, 3, 3, 5, 4, 3, 3, 4, }; SkTileMode tilemodes[NUM_COLS] = { SkTileMode::kClamp, SkTileMode::kRepeat, SkTileMode::kMirror, }; for (int cellRow = 0; cellRow < NUM_ROWS; cellRow++) { for (int cellCol = 0; cellCol < NUM_COLS; cellCol++) { create_gradient_points(cellRow, cellCol, points); auto shader = SkGradientShader::MakeLinear( points, colors, positions[cellRow], numGradientColors[cellRow], tilemodes[cellCol], 0, nullptr); shade_rect(canvas, shader, cellRow, cellCol); } } } private: typedef skiagm::GM INHERITED; }; DEF_GM(return new HardstopGradientShaderGM;)