91 lines
2.8 KiB
C++
91 lines
2.8 KiB
C++
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/*
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* Copyright 2021 Google LLC
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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 different gradients with an increasing number of
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* hardstops, from 1 to 100.
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*/
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#include "gm/gm.h"
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#include "include/core/SkCanvas.h"
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#include "include/core/SkColor.h"
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#include "include/core/SkPaint.h"
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#include "include/core/SkPoint.h"
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#include "include/core/SkRect.h"
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#include "include/core/SkRefCnt.h"
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#include "include/core/SkScalar.h"
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#include "include/core/SkShader.h"
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#include "include/core/SkSize.h"
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#include "include/core/SkString.h"
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#include "include/core/SkTileMode.h"
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#include "include/effects/SkGradientShader.h"
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const int kWidth = 1000;
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const int kHeight = 2000;
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const int kNumRows = 100;
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const int kCellHeight = kHeight / kNumRows;
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const int kPadHeight = 1;
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const int kRectHeight = kCellHeight - (2 * kPadHeight);
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class HardstopGradientsManyGM : public skiagm::GM {
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public:
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HardstopGradientsManyGM() {}
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protected:
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SkString onShortName() override {
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return SkString("hardstop_gradients_many");
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}
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SkISize onISize() override {
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return SkISize::Make(kWidth, kHeight);
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}
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void onDraw(SkCanvas* canvas) override {
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static constexpr SkPoint points[] = {
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SkPoint::Make(0, kRectHeight / 2),
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SkPoint::Make(kWidth, kRectHeight / 2),
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};
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std::vector<SkColor> colors;
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std::vector<SkScalar> positions;
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for (int row = 1; row <= kNumRows; ++row) {
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// Assemble a gradient containing a blue-to-white blend, repeated N times per row.
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colors.push_back(SK_ColorBLUE);
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colors.push_back(SK_ColorWHITE);
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positions = {0.0f};
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for (int pos = 1; pos < row; ++pos) {
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float place = SkScalar(pos) / SkScalar(row);
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positions.push_back(place);
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positions.push_back(place);
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}
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positions.push_back(1.0f);
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SkASSERT(positions.size() == colors.size());
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// Draw it.
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auto shader = SkGradientShader::MakeLinear(points,
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colors.data(),
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positions.data(),
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colors.size(),
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SkTileMode::kClamp,
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/*flags=*/0,
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/*localMatrix=*/nullptr);
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SkPaint paint;
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paint.setShader(shader);
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canvas->drawRect(SkRect::MakeXYWH(0, kPadHeight, kWidth, kRectHeight), paint);
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canvas->translate(0, kCellHeight);
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}
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}
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private:
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using INHERITED = skiagm::GM;
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};
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DEF_GM(return new HardstopGradientsManyGM;)
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