diff options
| -rw-r--r-- | gm/OverStroke.cpp | 108 |
1 files changed, 73 insertions, 35 deletions
diff --git a/gm/OverStroke.cpp b/gm/OverStroke.cpp index 0c5679786c..f7134cd26c 100644 --- a/gm/OverStroke.cpp +++ b/gm/OverStroke.cpp @@ -13,6 +13,12 @@ * overlap and create holes. There is not a really great algorithm for this * and several other 2D graphics engines have the same bug. * + * If we run this using Nvidia Path Renderer with: + * `path/to/dm --match OverStroke -w gm_out --gpu --config nvpr16` + * then we get correct results, so that is a possible direction of attack - + * use the GPU and a completely different algorithm to get correctness in + * Skia. + * * See crbug.com/589769 skbug.com/5405 skbug.com/5406 */ @@ -20,14 +26,28 @@ #include "gm.h" #include "SkPaint.h" #include "SkPath.h" +#include "SkPathMeasure.h" + +const SkScalar OVERSTROKE_WIDTH = 500.0f; +const SkScalar NORMALSTROKE_WIDTH = 3.0f; //////// path and paint builders +SkPaint make_normal_paint() { + SkPaint p; + p.setAntiAlias(true); + p.setStyle(SkPaint::kStroke_Style); + p.setStrokeWidth(NORMALSTROKE_WIDTH); + p.setColor(SK_ColorBLUE); + + return p; +} + SkPaint make_overstroke_paint() { SkPaint p; p.setAntiAlias(true); p.setStyle(SkPaint::kStroke_Style); - p.setStrokeWidth(500); + p.setStrokeWidth(OVERSTROKE_WIDTH); return p; } @@ -38,6 +58,7 @@ SkPath quad_path() { path.lineTo(100, 0); path.quadTo(50, -40, 0, 0); + path.close(); return path; } @@ -62,19 +83,50 @@ SkPath oval_path() { return path; } +SkPath ribs_path(SkPath path, SkScalar radius) { + SkPath ribs; + + const SkScalar spacing = 5.0f; + float accum = 0.0f; + + SkPathMeasure meas(path, false); + SkScalar length = meas.getLength(); + SkPoint pos; + SkVector tan; + while (accum < length) { + if (meas.getPosTan(accum, &pos, &tan)) { + tan.scale(radius); + tan.rotateCCW(); + + ribs.moveTo(pos.x() + tan.x(), pos.y() + tan.y()); + ribs.lineTo(pos.x() - tan.x(), pos.y() - tan.y()); + } + accum += spacing; + } + + return ribs; +} + +void draw_ribs(SkCanvas *canvas, SkPath path) { + SkPath ribs = ribs_path(path, OVERSTROKE_WIDTH/2.0f); + SkPaint p = make_normal_paint(); + p.setStrokeWidth(1); + p.setColor(SK_ColorBLUE); + p.setColor(SK_ColorGREEN); + + canvas->drawPath(ribs, p); +} + ///////// quads void draw_small_quad(SkCanvas *canvas) { // scaled so it's visible - canvas->scale(8, 8); - - SkPaint p; - p.setAntiAlias(true); - p.setStyle(SkPaint::kStroke_Style); - p.setStrokeWidth(3); + // canvas->scale(8, 8); + SkPaint p = make_normal_paint(); SkPath path = quad_path(); + draw_ribs(canvas, path); canvas->drawPath(path, p); } @@ -83,15 +135,14 @@ void draw_large_quad(SkCanvas *canvas) { SkPath path = quad_path(); canvas->drawPath(path, p); + draw_ribs(canvas, path); } void draw_quad_fillpath(SkCanvas *canvas) { SkPath path = quad_path(); SkPaint p = make_overstroke_paint(); - SkPaint fillp; - fillp.setAntiAlias(true); - fillp.setStyle(SkPaint::kStroke_Style); + SkPaint fillp = make_normal_paint(); fillp.setColor(SK_ColorMAGENTA); SkPath fillpath; @@ -101,7 +152,7 @@ void draw_quad_fillpath(SkCanvas *canvas) { } void draw_stroked_quad(SkCanvas *canvas) { - canvas->translate(200, 0); + canvas->translate(400, 0); draw_large_quad(canvas); draw_quad_fillpath(canvas); } @@ -109,16 +160,10 @@ void draw_stroked_quad(SkCanvas *canvas) { ////////// cubics void draw_small_cubic(SkCanvas *canvas) { - // scaled so it's visible - canvas->scale(8, 8); - - SkPaint p; - p.setAntiAlias(true); - p.setStyle(SkPaint::kStroke_Style); - p.setStrokeWidth(3); - + SkPaint p = make_normal_paint(); SkPath path = cubic_path(); + draw_ribs(canvas, path); canvas->drawPath(path, p); } @@ -127,15 +172,14 @@ void draw_large_cubic(SkCanvas *canvas) { SkPath path = cubic_path(); canvas->drawPath(path, p); + draw_ribs(canvas, path); } void draw_cubic_fillpath(SkCanvas *canvas) { SkPath path = cubic_path(); SkPaint p = make_overstroke_paint(); - SkPaint fillp; - fillp.setAntiAlias(true); - fillp.setStyle(SkPaint::kStroke_Style); + SkPaint fillp = make_normal_paint(); fillp.setColor(SK_ColorMAGENTA); SkPath fillpath; @@ -153,16 +197,11 @@ void draw_stroked_cubic(SkCanvas *canvas) { ////////// ovals void draw_small_oval(SkCanvas *canvas) { - // scaled so it's visible - canvas->scale(8, 8); - - SkPaint p; - p.setAntiAlias(true); - p.setStyle(SkPaint::kStroke_Style); - p.setStrokeWidth(3); + SkPaint p = make_normal_paint(); SkPath path = oval_path(); + draw_ribs(canvas, path); canvas->drawPath(path, p); } @@ -171,15 +210,14 @@ void draw_large_oval(SkCanvas *canvas) { SkPath path = oval_path(); canvas->drawPath(path, p); + draw_ribs(canvas, path); } void draw_oval_fillpath(SkCanvas *canvas) { SkPath path = oval_path(); SkPaint p = make_overstroke_paint(); - SkPaint fillp; - fillp.setAntiAlias(true); - fillp.setStyle(SkPaint::kStroke_Style); + SkPaint fillp = make_normal_paint(); fillp.setColor(SK_ColorMAGENTA); SkPath fillpath; @@ -210,9 +248,9 @@ DEF_SIMPLE_GM(OverStroke, canvas, 500, 500) { int y = (int)(i / width); canvas->save(); - canvas->translate(200.0f * x, 150.0f * y); - canvas->scale(0.25f, 0.25f); - canvas->translate(100.0f, 400.0f); + canvas->translate(150.0f * x, 150.0f * y); + canvas->scale(0.2f, 0.2f); + canvas->translate(300.0f, 400.0f); examples[i](canvas); |