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