/*
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* Copyright 2018 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/*
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* This GM presents a variety of gradients meant to test the correctness of the analytic
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* GrUnrolledBinaryGradientColorizer, which can handle arbitrary gradients with 1 to 8 interpolation
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* intervals. These intervals can be either hardstops or smooth color transitions.
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*
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* It produces an image similar to that of GM_hardstop_gradients, but is arranged as follows:
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*
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* | Clamp |
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* |________________|
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* | M1 M2 M3 M4 |
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* ___________|________________|
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* 1 |
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* 2 |
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* 3 |
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* 4 |
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* 5 |
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* 6 |
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* 7 |
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* 8 |
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* The M-modes are different ways of interlveaving hardstops with smooth transitions:
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* - M1 = All smooth transitions
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* - M2 = All hard stops
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* - M5 = Alternating smooth then hard
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* - M6 = Alternating hard then smooth
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*
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* Only clamping is tested since this is focused more on within the interpolation region behavior,
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* compared to overall behavior.
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*/
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#include "gm.h"
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#include "SkGradientShader.h"
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// All positions must be divided by the target interval count, which will produce the expected
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// normalized position array for that interval number (assuming an appropriate color count is
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// provided).
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const int M1_POSITIONS[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8 };
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const int M2_POSITIONS[] = { 0, 1,1, 2,2, 3,3, 4,4, 5,5, 6,6, 7,7, 8 };
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const int M3_POSITIONS[] = { 0, 1, 2,2, 3, 4,4, 5, 6,6, 7, 8 };
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const int M4_POSITIONS[] = { 0, 1,1, 2, 3,3, 4, 5,5, 6, 7,7, 8 };
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// Color count = index of first occurrence of interval count value in Mx_POSITIONS array.
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const int INT1_COLOR_COUNTS[] = { 2, 2, 2, 2 };
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const int INT2_COLOR_COUNTS[] = { 3, 4, 3, 4 };
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const int INT3_COLOR_COUNTS[] = { 4, 6, 5, 5 };
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const int INT4_COLOR_COUNTS[] = { 5, 8, 6, 7 };
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const int INT5_COLOR_COUNTS[] = { 6, 10, 8, 8 };
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const int INT6_COLOR_COUNTS[] = { 7, 12, 9, 10 };
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const int INT7_COLOR_COUNTS[] = { 8, 14, 11, 11 };
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const int INT8_COLOR_COUNTS[] = { 9, 16, 12, 13 };
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// Cycle through defined colors for positions 0 through 8.
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const SkColor COLORS[] = {
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SK_ColorDKGRAY,
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SK_ColorRED,
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SK_ColorYELLOW,
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SK_ColorGREEN,
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SK_ColorCYAN,
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SK_ColorBLUE,
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SK_ColorMAGENTA,
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SK_ColorBLACK,
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SK_ColorLTGRAY
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};
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const int* INTERVAL_COLOR_COUNTS[] = {
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INT1_COLOR_COUNTS,
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INT2_COLOR_COUNTS,
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INT3_COLOR_COUNTS,
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INT4_COLOR_COUNTS,
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INT5_COLOR_COUNTS,
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INT6_COLOR_COUNTS,
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INT7_COLOR_COUNTS,
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INT8_COLOR_COUNTS
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};
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const int COLOR_COUNT = SK_ARRAY_COUNT(COLORS);
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const int* M_POSITIONS[] = {
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M1_POSITIONS,
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M2_POSITIONS,
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M3_POSITIONS,
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M4_POSITIONS
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};
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const int WIDTH = 500;
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const int HEIGHT = 500;
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const int NUM_ROWS = 8;
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const int NUM_COLS = 4;
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const int CELL_WIDTH = WIDTH / NUM_COLS;
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const int CELL_HEIGHT = HEIGHT / NUM_ROWS;
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const int PAD_WIDTH = 3;
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const int PAD_HEIGHT = 3;
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const int RECT_WIDTH = CELL_WIDTH - (2 * PAD_WIDTH);
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const int RECT_HEIGHT = CELL_HEIGHT - (2 * PAD_HEIGHT);
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static void shade_rect(SkCanvas* canvas, sk_sp<SkShader> shader, int cellRow, int cellCol) {
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SkPaint paint;
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paint.setShader(shader);
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canvas->save();
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canvas->translate(SkIntToScalar(cellCol * CELL_WIDTH + PAD_WIDTH),
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SkIntToScalar(cellRow * CELL_HEIGHT + PAD_HEIGHT));
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const SkRect rect = SkRect::MakeWH(SkIntToScalar(RECT_WIDTH), SkIntToScalar(RECT_HEIGHT));
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canvas->drawRect(rect, paint);
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canvas->restore();
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}
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class AnalyticGradientShaderGM : public skiagm::GM {
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public:
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AnalyticGradientShaderGM() {
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}
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protected:
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SkString onShortName() override {
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return SkString("analytic_gradients");
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}
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SkISize onISize() override {
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return SkISize::Make(1024, 512);
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}
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void onDraw(SkCanvas* canvas) override {
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const SkPoint points[2] = { SkPoint::Make(0, 0), SkPoint::Make(RECT_WIDTH, 0.0) };
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for (int cellRow = 0; cellRow < NUM_ROWS; cellRow++) {
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// Each interval has 4 different color counts, one per mode
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const int* colorCounts = INTERVAL_COLOR_COUNTS[cellRow]; // Has len = 4
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for (int cellCol = 0; cellCol < NUM_COLS; cellCol++) {
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// create_gradient_points(cellRow, cellCol, points);
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// Get the color count dependent on interval and mode
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int colorCount = colorCounts[cellCol];
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// Get the positions given the mode
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const int* layout = M_POSITIONS[cellCol];
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// Collect positions and colors specific to the interval+mode normalizing the
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// position based on the interval count (== cellRow+1)
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SkAutoSTMalloc<4, SkColor> colors(colorCount);
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SkAutoSTMalloc<4, SkScalar> positions(colorCount);
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int j = 0;
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for (int i = 0; i < colorCount; i++) {
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positions[i] = SkIntToScalar(layout[i]) / (cellRow + 1);
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colors[i] = COLORS[j % COLOR_COUNT];
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j++;
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}
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auto shader = SkGradientShader::MakeLinear(
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points,
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colors.get(),
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positions.get(),
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colorCount,
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SkShader::kClamp_TileMode,
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0,
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nullptr);
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shade_rect(canvas, shader, cellRow, cellCol);
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}
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}
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}
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private:
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typedef skiagm::GM INHERITED;
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};
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DEF_GM(return new AnalyticGradientShaderGM;)
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