| /* |
| * Copyright 2015 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/SkFont.h" |
| #include "include/core/SkPaint.h" |
| #include "include/core/SkPoint.h" |
| #include "include/core/SkRect.h" |
| #include "include/core/SkScalar.h" |
| #include "include/core/SkShader.h" |
| #include "include/core/SkSize.h" |
| #include "include/core/SkString.h" |
| #include "include/core/SkTypeface.h" |
| #include "include/core/SkTypes.h" |
| #include "tools/ToolUtils.h" |
| |
| // This class of GMs test how edges/verts snap near rounding boundaries in device space without |
| // anti-aliaing. |
| class PixelSnapGM : public skiagm::GM { |
| public: |
| PixelSnapGM() {} |
| |
| protected: |
| // kTrans should be even or checkboards wont agree in different test cases. |
| inline static constexpr int kTrans = 14; |
| inline static constexpr int kLabelPad = 4; |
| // The inverse of this value should be a perfect SkScalar. |
| inline static constexpr int kSubPixelSteps = 8; |
| inline static constexpr int kLabelTextSize = 9; |
| |
| static_assert(kSubPixelSteps < 99, "label_offset_too_small"); |
| inline static constexpr int kLabelOffsetX = 2 * kLabelTextSize + kLabelPad; |
| inline static constexpr int kLabelOffsetY = kLabelTextSize + kLabelPad; |
| |
| SkISize onISize() override { |
| return SkISize::Make((kSubPixelSteps + 1) * kTrans + kLabelOffsetX + kLabelPad, |
| (kSubPixelSteps + 1) * kTrans + kLabelOffsetY + kLabelPad); |
| } |
| |
| void onDraw(SkCanvas* canvas) override { |
| SkPaint bgPaint; |
| bgPaint.setShader(ToolUtils::create_checkerboard_shader(0xFFAAAAAA, 0xFF777777, 1)); |
| canvas->drawPaint(bgPaint); |
| |
| SkString offset; |
| SkPaint labelPaint; |
| labelPaint.setColor(SK_ColorWHITE); |
| SkFont font(ToolUtils::create_portable_typeface(), SkIntToScalar(kLabelTextSize)); |
| SkPaint linePaint; |
| linePaint.setColor(SK_ColorWHITE); |
| |
| // Draw row labels |
| canvas->save(); |
| canvas->translate(0, SkIntToScalar(kLabelOffsetY)); |
| for (int i = 0; i <= kSubPixelSteps; ++i) { |
| offset.printf("%d", i); |
| canvas->drawString(offset, 0, i * kTrans + SkIntToScalar(kLabelTextSize), |
| font, labelPaint); |
| } |
| canvas->restore(); |
| |
| // Draw col labels |
| canvas->save(); |
| canvas->translate(SkIntToScalar(kLabelOffsetX), 0); |
| for (int i = 0; i <= kSubPixelSteps; ++i) { |
| offset.printf("%d", i); |
| canvas->drawString(offset, i * SkIntToScalar(kTrans), SkIntToScalar(kLabelTextSize), |
| font, labelPaint); |
| } |
| canvas->restore(); |
| |
| canvas->translate(SkIntToScalar(kLabelOffsetX), SkIntToScalar(kLabelOffsetY)); |
| |
| // Draw test case grid lines (Draw them all at pixel centers to hopefully avoid any |
| // snapping issues). |
| for (int i = 0; i <= kSubPixelSteps + 1; ++i) { |
| canvas->drawLine(0.5f, |
| i * SkIntToScalar(kTrans) + 0.5f, |
| SkIntToScalar(kTrans) * (kSubPixelSteps + 1) + 0.5f, |
| i * SkIntToScalar(kTrans) + 0.5f, |
| linePaint); |
| canvas->drawLine(i * SkIntToScalar(kTrans) + 0.5f, |
| 0.5f, |
| i * SkIntToScalar(kTrans) + 0.5f, |
| SkIntToScalar(kTrans) * (kSubPixelSteps + 1) + 0.5f, |
| linePaint); |
| } |
| |
| for (int i = 0; i <= kSubPixelSteps; ++i) { |
| for (int j = 0; j <= kSubPixelSteps; ++j) { |
| canvas->save(); |
| // +1's account for the grid lines around each test case. |
| canvas->translate(j * (kTrans + 1.f/kSubPixelSteps) + 1, |
| i * (kTrans + 1.f/kSubPixelSteps) + 1); |
| this->drawElement(canvas); |
| canvas->restore(); |
| } |
| } |
| } |
| |
| virtual void drawElement(SkCanvas*) = 0; |
| |
| private: |
| using INHERITED = skiagm::GM; |
| }; |
| |
| class PointSnapGM : public PixelSnapGM { |
| protected: |
| SkString onShortName() override { return SkString("pixel_snap_point"); } |
| void drawElement(SkCanvas* canvas) override { |
| const SkPoint pt = { 1, 1 }; |
| SkPaint paint; |
| paint.setColor(SK_ColorBLUE); |
| canvas->drawPoints(SkCanvas::kPoints_PointMode, 1, &pt, paint); |
| } |
| |
| private: |
| using INHERITED = PixelSnapGM; |
| }; |
| |
| class LineSnapGM : public PixelSnapGM { |
| protected: |
| SkString onShortName() override { return SkString("pixel_snap_line"); } |
| void drawElement(SkCanvas* canvas) override { |
| SkPaint paint; |
| paint.setColor(SK_ColorGREEN); |
| // Draw a horizontal and vertical line, each length 3. |
| canvas->drawLine(1, 1, 4, 1, paint); |
| canvas->drawLine(6, 1, 6, 4, paint); |
| } |
| |
| private: |
| using INHERITED = PixelSnapGM; |
| }; |
| |
| class RectSnapGM : public PixelSnapGM { |
| protected: |
| SkString onShortName() override { return SkString("pixel_snap_rect"); } |
| void drawElement(SkCanvas* canvas) override { |
| SkPaint paint; |
| paint.setColor(SK_ColorRED); |
| canvas->drawRect(SkRect::MakeXYWH(1, 1, 3, 3), paint); |
| } |
| |
| private: |
| using INHERITED = PixelSnapGM; |
| }; |
| |
| class ComboSnapGM : public PixelSnapGM { |
| protected: |
| SkString onShortName() override { return SkString("pixel_snap_combo"); } |
| void drawElement(SkCanvas* canvas) override { |
| SkPaint paint; |
| paint.setAntiAlias(false); |
| // A rectangle that exactly covers a pixel, a point at each corner, 8 horiz/vert lines |
| // at rect corners (two at each corner, extending away from rect). They are drawn in this |
| // order lines (green), points (blue), rect(red). |
| SkRect rect = SkRect::MakeXYWH(3, 3, 1, 1); |
| paint.setColor(SK_ColorGREEN); |
| const SkPoint lines[] = { |
| { 3, 3 }, { 0, 3 }, |
| { 3, 3 }, { 3, 0 }, |
| { 4, 3 }, { 7, 3 }, |
| { 4, 3 }, { 4, 0 }, |
| { 3, 4 }, { 0, 4 }, |
| { 3, 4 }, { 3, 7 }, |
| { 4, 4 }, { 7, 4 }, |
| { 4, 4 }, { 4, 7 }, |
| }; |
| canvas->drawPoints(SkCanvas::kLines_PointMode, std::size(lines), lines, paint); |
| |
| const SkPoint pts[] = { |
| { 4, 3 }, { 4, 4, }, { 3, 3 }, { 3, 4 }, |
| }; |
| paint.setColor(SK_ColorBLUE); |
| canvas->drawPoints(SkCanvas::kPoints_PointMode, std::size(pts), pts, paint); |
| |
| paint.setColor(SK_ColorRED); |
| canvas->drawRect(rect, paint); |
| } |
| |
| private: |
| using INHERITED = PixelSnapGM; |
| }; |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| DEF_GM(return new PointSnapGM;) |
| DEF_GM(return new LineSnapGM;) |
| DEF_GM(return new RectSnapGM;) |
| DEF_GM(return new ComboSnapGM;) |