gm/occludedrrectblur.cpp

   1 /*
   2  * Copyright 2016 Google Inc.
   3  *
   4  * Use of this source code is governed by a BSD-style license that can be
   5  * found in the LICENSE file.
   6  */
   7
   8 #include "gm.h"
   9 #include "sk_tool_utils.h"
  10 #include "SkBlurMaskFilter.h"
  11 #include "SkRRect.h"
  12
  13 static SkRect offset_center_to(const SkIRect& src, SkScalar x, SkScalar y) {
  14     SkScalar halfW = 0.5f * src.width();
  15     SkScalar halfH = 0.5f * src.height();
  16
  17     return SkRect::MakeLTRB(x - halfW, y - halfH, x + halfW, y + halfH);
  18 }
  19
  20 static void draw_rrect(SkCanvas* canvas, const SkRRect& rr, const SkRRect& occRR) {
  21     const SkScalar kBlurSigma = 5.0f;
  22
  23     SkRect occRect;
  24     SkColor strokeColor;
  25
  26     {
  27         SkRect occRect1 = sk_tool_utils::compute_central_occluder(occRR);
  28         SkRect occRect2 = sk_tool_utils::compute_widest_occluder(occRR);
  29         SkRect occRect3 = sk_tool_utils::compute_tallest_occluder(occRR);
  30
  31         SkScalar area1 = occRect1.width() * occRect1.height();
  32         SkScalar area2 = occRect2.width() * occRect2.height();
  33         SkScalar area3 = occRect3.width() * occRect3.height();
  34
  35         if (area1 >= area2 && area1 >= area3) {
  36             strokeColor = SK_ColorRED;
  37             occRect = occRect1;
  38         } else if (area2 > area3) {
  39             strokeColor = SK_ColorYELLOW;
  40             occRect = occRect2;
  41         } else {
  42             strokeColor = SK_ColorCYAN;
  43             occRect = occRect3;
  44         }
  45     }
  46
  47     // draw the blur
  48     SkPaint paint;
  49     paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle, kBlurSigma, occRect));
  50     canvas->drawRRect(rr, paint);
  51
  52     // draw the stroked geometry of the full occluder
  53     SkPaint stroke;
  54     stroke.setStyle(SkPaint::kStroke_Style);
  55     stroke.setColor(SK_ColorBLUE);
  56     canvas->drawRRect(occRR, stroke);
  57
  58     // draw the geometry of the occluding rect
  59     stroke.setColor(strokeColor);
  60     canvas->drawRect(occRect, stroke);
  61 }
  62
  63 static void draw_45(SkCanvas* canvas, SkRRect::Corner corner,
  64                     SkScalar dist, const SkPoint& center) {
  65     SkRRect::Corner left = SkRRect::kUpperLeft_Corner, right = SkRRect::kUpperLeft_Corner;
  66     SkVector dir = { 0, 0 };
  67
  68     constexpr SkScalar kSize = 64.0f / SK_ScalarSqrt2;
  69
  70     switch (corner) {
  71     case SkRRect::kUpperLeft_Corner:
  72         left = SkRRect::kUpperRight_Corner;
  73         right = SkRRect::kLowerLeft_Corner;
  74
  75         dir.set(-SK_ScalarRoot2Over2, -SK_ScalarRoot2Over2);
  76         break;
  77     case SkRRect::kUpperRight_Corner:
  78         left = SkRRect::kUpperLeft_Corner;
  79         right = SkRRect::kLowerRight_Corner;
  80         dir.set(SK_ScalarRoot2Over2, -SK_ScalarRoot2Over2);
  81         break;
  82     case SkRRect::kLowerRight_Corner:
  83         left = SkRRect::kLowerLeft_Corner;
  84         right = SkRRect::kUpperRight_Corner;
  85         dir.set(SK_ScalarRoot2Over2, SK_ScalarRoot2Over2);
  86         break;
  87     case SkRRect::kLowerLeft_Corner:
  88         left = SkRRect::kLowerRight_Corner;
  89         right = SkRRect::kUpperLeft_Corner;
  90         dir.set(-SK_ScalarRoot2Over2, SK_ScalarRoot2Over2);
  91         break;
  92     default:
  93         SkFAIL("Invalid shape.");
  94     }
  95
  96     SkRect r = SkRect::MakeWH(kSize, kSize);
  97     // UL, UR, LR, LL
  98     SkVector radii[4] = { { 0.0f, 0.0f }, { 0.0f, 0.0f }, { 0.0f, 0.0f }, { 0.0f, 0.0f } };
  99     radii[left] = SkVector::Make(kSize, kSize);
 100     radii[right] = SkVector::Make(kSize, kSize);
 101     SkRRect rr;
 102     rr.setRectRadii(
 103             offset_center_to(r.roundOut(), center.fX + dist*dir.fX, center.fY + dist*dir.fY),
 104             radii);
 105
 106     SkRRect occRR;
 107     dist -= 10.0f;
 108     occRR.setRectRadii(
 109             offset_center_to(r.roundOut(), center.fX + dist*dir.fX, center.fY + dist*dir.fY),
 110             radii);
 111
 112     draw_rrect(canvas, rr, occRR);
 113 }
 114
 115 static void draw_45_simple(SkCanvas* canvas, const SkVector& v,
 116                            SkScalar dist, const SkPoint& center) {
 117     SkIRect r = SkIRect::MakeWH(64, 64);
 118     SkRRect rr = SkRRect::MakeRectXY(
 119                             offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY),
 120                             8, 8);
 121
 122     dist -= 10.0f;
 123     SkRRect occRR = SkRRect::MakeRectXY(
 124                             offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY),
 125                             8, 8);
 126
 127     draw_rrect(canvas, rr, occRR);
 128 }
 129
 130 static void draw_90(SkCanvas* canvas, const SkVector& v, SkScalar dist, const SkPoint& center) {
 131     constexpr int kWidth = 25;
 132
 133     SkIRect r;
 134     if (fabs(v.fX) < fabs(v.fY)) {
 135         r = SkIRect::MakeWH(kWidth, 64);
 136     } else {
 137         r = SkIRect::MakeWH(64, kWidth);
 138     }
 139     SkRRect rr = SkRRect::MakeOval(
 140                             offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY));
 141
 142     dist -= 10.0f;
 143     SkRRect occRR = SkRRect::MakeOval(
 144                             offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY));
 145
 146     draw_rrect(canvas, rr, occRR);
 147 }
 148
 149 static void draw_90_simple(SkCanvas* canvas, const SkVector& v,
 150                            SkScalar dist, const SkPoint& center) {
 151     constexpr int kLength = 128;
 152     // The width needs to be larger than 2*3*blurRadii+2*cornerRadius for the analytic
 153     // RRect blur to kick in
 154     constexpr int kWidth = 47;
 155
 156     SkIRect r;
 157     if (fabs(v.fX) < fabs(v.fY)) {
 158         r = SkIRect::MakeWH(kLength, kWidth);
 159     } else {
 160         r = SkIRect::MakeWH(kWidth, kLength);
 161     }
 162     SkRRect rr = SkRRect::MakeRectXY(
 163                             offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY),
 164                             8, 8);
 165
 166     dist -= 10.0f;
 167     SkRRect occRR = SkRRect::MakeRectXY(
 168                             offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY),
 169                             8, 8);
 170
 171     draw_rrect(canvas, rr, occRR);
 172 }
 173
 174 static void draw_30_60(SkCanvas* canvas, SkRRect::Corner corner, const SkVector& v,
 175                        SkScalar dist, const SkPoint& center) {
 176     SkRRect::Corner left = SkRRect::kUpperLeft_Corner, right = SkRRect::kUpperLeft_Corner;
 177
 178     constexpr int kLength = 64;
 179     constexpr int kWidth = 30;
 180
 181     switch (corner) {
 182     case SkRRect::kUpperLeft_Corner:
 183         left = SkRRect::kUpperRight_Corner;
 184         right = SkRRect::kLowerLeft_Corner;
 185         break;
 186     case SkRRect::kUpperRight_Corner:
 187         left = SkRRect::kUpperLeft_Corner;
 188         right = SkRRect::kLowerRight_Corner;
 189         break;
 190     case SkRRect::kLowerRight_Corner:
 191         left = SkRRect::kLowerLeft_Corner;
 192         right = SkRRect::kUpperRight_Corner;
 193         break;
 194     case SkRRect::kLowerLeft_Corner:
 195         left = SkRRect::kLowerRight_Corner;
 196         right = SkRRect::kUpperLeft_Corner;
 197         break;
 198     default:
 199         SkFAIL("Invalid shape.");
 200     }
 201
 202     SkIRect r;
 203     if (fabs(v.fX) < fabs(v.fY)) {
 204         r = SkIRect::MakeWH(kLength, kWidth);
 205     } else {
 206         r = SkIRect::MakeWH(kWidth, kLength);
 207     }
 208     // UL, UR, LR, LL
 209     SkVector radii[4] = { { 0.0f, 0.0f }, { 0.0f, 0.0f }, { 0.0f, 0.0f }, { 0.0f, 0.0f } };
 210     radii[left] = SkVector::Make(SkIntToScalar(kWidth), SkIntToScalar(kWidth));
 211     radii[right] = SkVector::Make(SkIntToScalar(kWidth), SkIntToScalar(kWidth));
 212     SkRRect rr;
 213     rr.setRectRadii(offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY), radii);
 214
 215     dist -= 10.0f;
 216     SkRRect occRR;
 217     occRR.setRectRadii(offset_center_to(r, center.fX + dist*v.fX, center.fY + dist*v.fY), radii);
 218     draw_rrect(canvas, rr, occRR);
 219 }
 220
 221 namespace skiagm {
 222
 223 class OccludedRRectBlurGM : public GM {
 224 public:
 225     OccludedRRectBlurGM() {
 226         this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
 227     }
 228
 229 protected:
 230
 231     SkString onShortName() override {
 232         return SkString("occludedrrectblur");
 233     }
 234
 235     SkISize onISize() override {
 236         return SkISize::Make(kWidth, kHeight);
 237     }
 238
 239     void onDraw(SkCanvas* canvas) override {
 240         const SkPoint center = SkPoint::Make(kWidth/2, kHeight/2);
 241
 242         // outer-most big RR
 243         {
 244             SkIRect r = SkIRect::MakeWH(420, 420);
 245             SkRRect rr = SkRRect::MakeRectXY(offset_center_to(r, center.fX, center.fY), 64, 64);
 246             draw_rrect(canvas, rr, rr);
 247
 248 #if 1
 249             // TODO: remove this. Until we actually start skipping the middle draw we need this
 250             // to provide contrast
 251             SkPaint temp;
 252             temp.setColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
 253             r.inset(32, 32);
 254             canvas->drawRect(offset_center_to(r, center.fX, center.fY), temp);
 255 #endif
 256         }
 257
 258         // center circle
 259         {
 260             SkIRect r = SkIRect::MakeWH(32, 32);
 261             SkRRect rr = SkRRect::MakeOval(offset_center_to(r, center.fX, center.fY));
 262             draw_rrect(canvas, rr, rr);
 263         }
 264
 265         draw_45(canvas, SkRRect::kUpperLeft_Corner, 64, center);
 266         draw_45(canvas, SkRRect::kUpperRight_Corner, 64, center);
 267         draw_45(canvas, SkRRect::kLowerRight_Corner, 64, center);
 268         draw_45(canvas, SkRRect::kLowerLeft_Corner, 64, center);
 269
 270         draw_90(canvas, SkVector::Make(-1.0f, 0.0f), 64, center);
 271         draw_90(canvas, SkVector::Make(0.0f, -1.0f), 64, center);
 272         draw_90(canvas, SkVector::Make(1.0f, 0.0f), 64, center);
 273         draw_90(canvas, SkVector::Make(0.0f, 1.0f), 64, center);
 274
 275         constexpr SkScalar kRoot3Over2 = 0.8660254037844386f;
 276
 277         draw_30_60(canvas, SkRRect::kLowerLeft_Corner,
 278                    SkVector::Make(0.5f, kRoot3Over2), 120, center);
 279         draw_30_60(canvas, SkRRect::kUpperRight_Corner,
 280                    SkVector::Make(kRoot3Over2, 0.5f), 120, center);
 281
 282         draw_30_60(canvas, SkRRect::kUpperLeft_Corner,
 283                    SkVector::Make(-0.5f, kRoot3Over2), 120, center);
 284         draw_30_60(canvas, SkRRect::kLowerRight_Corner,
 285                    SkVector::Make(-kRoot3Over2, 0.5f), 120, center);
 286
 287         draw_30_60(canvas, SkRRect::kLowerLeft_Corner,
 288                    SkVector::Make(-0.5f, -kRoot3Over2), 120, center);
 289         draw_30_60(canvas, SkRRect::kUpperRight_Corner,
 290                    SkVector::Make(-kRoot3Over2, -0.5f), 120, center);
 291
 292         draw_30_60(canvas, SkRRect::kUpperLeft_Corner,
 293                    SkVector::Make(0.5f, -kRoot3Over2), 120, center);
 294         draw_30_60(canvas, SkRRect::kLowerRight_Corner,
 295                    SkVector::Make(kRoot3Over2, -0.5f), 120, center);
 296
 297         draw_45_simple(canvas, SkVector::Make(-SK_ScalarRoot2Over2, -SK_ScalarRoot2Over2),
 298                        210, center);
 299         draw_45_simple(canvas, SkVector::Make(SK_ScalarRoot2Over2, -SK_ScalarRoot2Over2),
 300                        210, center);
 301         draw_45_simple(canvas, SkVector::Make(SK_ScalarRoot2Over2, SK_ScalarRoot2Over2),
 302                        210, center);
 303         draw_45_simple(canvas, SkVector::Make(-SK_ScalarRoot2Over2, SK_ScalarRoot2Over2),
 304                        210, center);
 305
 306         draw_90_simple(canvas, SkVector::Make(-1.0f, 0.0f), 160, center);
 307         draw_90_simple(canvas, SkVector::Make(0.0f, -1.0f), 160, center);
 308         draw_90_simple(canvas, SkVector::Make(1.0f, 0.0f), 160, center);
 309         draw_90_simple(canvas, SkVector::Make(0.0f, 1.0f), 160, center);
 310     }
 311
 312 private:
 313     static constexpr int kWidth = 440;
 314     static constexpr int kHeight = 440;
 315
 316     typedef GM INHERITED;
 317 };
 318
 319 //////////////////////////////////////////////////////////////////////////////
 320
 321 DEF_GM(return new OccludedRRectBlurGM;)
 322 }