SkRRect.h revision f1f66c0c8623805fdb88f09c0d87cbdd1745e12b
1/* 2 * Copyright 2012 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#ifndef SkRRect_DEFINED 9#define SkRRect_DEFINED 10 11#include "SkRect.h" 12#include "SkPoint.h" 13 14class SkPath; 15class SkMatrix; 16 17// Path forward: 18// core work 19// add validate method (all radii positive, all radii sums < rect size, etc.) 20// add contains(SkRect&) - for clip stack 21// add contains(SkRRect&) - for clip stack 22// add heart rect computation (max rect inside RR) 23// add 9patch rect computation 24// add growToInclude(SkPath&) 25// analysis 26// use growToInclude to fit skp round rects & generate stats (RRs vs. real paths) 27// check on # of rectorus's the RRs could handle 28// rendering work 29// update SkPath.addRRect() to only use quads 30// add GM and bench 31// further out 32// detect and triangulate RRectorii rather than falling back to SW in Ganesh 33// 34 35/** \class SkRRect 36 37 The SkRRect class represents a rounded rect with a potentially different 38 radii for each corner. It does not have a constructor so must be 39 initialized with one of the initialization functions (e.g., setEmpty, 40 setRectRadii, etc.) 41 42 This class is intended to roughly match CSS' border-*-*-radius capabilities. 43 This means: 44 If either of a corner's radii are 0 the corner will be square. 45 Negative radii are not allowed (they are clamped to zero). 46 If the corner curves overlap they will be proportionally reduced to fit. 47*/ 48class SK_API SkRRect { 49public: 50 /** 51 * Enum to capture the various possible subtypes of RR. Accessed 52 * by type(). The subtypes become progressively less restrictive. 53 */ 54 enum Type { 55 // !< Internal indicator that the sub type must be computed. 56 kUnknown_Type = -1, 57 58 // !< The RR is empty 59 kEmpty_Type, 60 61 //!< The RR is actually a (non-empty) rect (i.e., at least one radius 62 //!< at each corner is zero) 63 kRect_Type, 64 65 //!< The RR is actually a (non-empty) oval (i.e., all x radii are equal 66 //!< and >= width/2 and all the y radii are equal and >= height/2 67 kOval_Type, 68 69 //!< The RR is non-empty and all the x radii are equal & all y radii 70 //!< are equal but it is not an oval (i.e., there are lines between 71 //!< the curves) nor a rect (i.e., both radii are non-zero) 72 kSimple_Type, 73 74 //!< A fully general (non-empty) RR. Some of the x and/or y radii are 75 //!< different from the others and there must be one corner where 76 //!< both radii are non-zero. 77 kComplex_Type, 78 }; 79 80 /** 81 * Returns the RR's sub type. 82 */ 83 Type getType() const { 84 SkDEBUGCODE(this->validate();) 85 86 if (kUnknown_Type == fType) { 87 this->computeType(); 88 } 89 SkASSERT(kUnknown_Type != fType); 90 return fType; 91 } 92 93 Type type() const { return this->getType(); } 94 95 inline bool isEmpty() const { return kEmpty_Type == this->getType(); } 96 inline bool isRect() const { return kRect_Type == this->getType(); } 97 inline bool isOval() const { return kOval_Type == this->getType(); } 98 inline bool isSimple() const { return kSimple_Type == this->getType(); } 99 inline bool isSimpleCircular() const { 100 return this->isSimple() && fRadii[0].fX == fRadii[0].fY; 101 } 102 inline bool isComplex() const { return kComplex_Type == this->getType(); } 103 104 SkScalar width() const { return fRect.width(); } 105 SkScalar height() const { return fRect.height(); } 106 107 /** 108 * Set this RR to the empty rectangle (0,0,0,0) with 0 x & y radii. 109 */ 110 void setEmpty() { 111 fRect.setEmpty(); 112 memset(fRadii, 0, sizeof(fRadii)); 113 fType = kEmpty_Type; 114 115 SkDEBUGCODE(this->validate();) 116 } 117 118 /** 119 * Set this RR to match the supplied rect. All radii will be 0. 120 */ 121 void setRect(const SkRect& rect) { 122 if (rect.isEmpty()) { 123 this->setEmpty(); 124 return; 125 } 126 127 fRect = rect; 128 memset(fRadii, 0, sizeof(fRadii)); 129 fType = kRect_Type; 130 131 SkDEBUGCODE(this->validate();) 132 } 133 134 /** 135 * Set this RR to match the supplied oval. All x radii will equal half the 136 * width and all y radii will equal half the height. 137 */ 138 void setOval(const SkRect& oval) { 139 if (oval.isEmpty()) { 140 this->setEmpty(); 141 return; 142 } 143 144 SkScalar xRad = SkScalarHalf(oval.width()); 145 SkScalar yRad = SkScalarHalf(oval.height()); 146 147 fRect = oval; 148 for (int i = 0; i < 4; ++i) { 149 fRadii[i].set(xRad, yRad); 150 } 151 fType = kOval_Type; 152 153 SkDEBUGCODE(this->validate();) 154 } 155 156 /** 157 * Initialize the RR with the same radii for all four corners. 158 */ 159 void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad); 160 161 /** 162 * Initialize the RR with potentially different radii for all four corners. 163 */ 164 void setRectRadii(const SkRect& rect, const SkVector radii[4]); 165 166 // The radii are stored in UL, UR, LR, LL order. 167 enum Corner { 168 kUpperLeft_Corner, 169 kUpperRight_Corner, 170 kLowerRight_Corner, 171 kLowerLeft_Corner 172 }; 173 174 const SkRect& rect() const { return fRect; } 175 const SkVector& radii(Corner corner) const { return fRadii[corner]; } 176 const SkRect& getBounds() const { return fRect; } 177 178 /** 179 * When a rrect is simple, all of its radii are equal. This returns one 180 * of those radii. This call requires the rrect to be non-complex. 181 */ 182 const SkVector& getSimpleRadii() const { 183 SkASSERT(!this->isComplex()); 184 return fRadii[0]; 185 } 186 187 friend bool operator==(const SkRRect& a, const SkRRect& b) { 188 return a.fRect == b.fRect && 189 SkScalarsEqual(a.fRadii[0].asScalars(), 190 b.fRadii[0].asScalars(), 8); 191 } 192 193 friend bool operator!=(const SkRRect& a, const SkRRect& b) { 194 return a.fRect != b.fRect || 195 !SkScalarsEqual(a.fRadii[0].asScalars(), 196 b.fRadii[0].asScalars(), 8); 197 } 198 199 /** 200 * Call inset on the bounds, and adjust the radii to reflect what happens 201 * in stroking: If the corner is sharp (no curvature), leave it alone, 202 * otherwise we grow/shrink the radii by the amount of the inset. If a 203 * given radius becomes negative, it is pinned to 0. 204 * 205 * It is valid for dst == this. 206 */ 207 void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const; 208 209 void inset(SkScalar dx, SkScalar dy) { 210 this->inset(dx, dy, this); 211 } 212 213 /** 214 * Call outset on the bounds, and adjust the radii to reflect what happens 215 * in stroking: If the corner is sharp (no curvature), leave it alone, 216 * otherwise we grow/shrink the radii by the amount of the inset. If a 217 * given radius becomes negative, it is pinned to 0. 218 * 219 * It is valid for dst == this. 220 */ 221 void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const { 222 this->inset(-dx, -dy, dst); 223 } 224 void outset(SkScalar dx, SkScalar dy) { 225 this->inset(-dx, -dy, this); 226 } 227 228 /** 229 * Translate the rrect by (dx, dy). 230 */ 231 void offset(SkScalar dx, SkScalar dy) { 232 fRect.offset(dx, dy); 233 } 234 235 /** 236 * Returns true if 'rect' is wholy inside the RR, and both 237 * are not empty. 238 */ 239 bool contains(const SkRect& rect) const; 240 241 SkDEBUGCODE(void validate() const;) 242 243 enum { 244 kSizeInMemory = 12 * sizeof(SkScalar) 245 }; 246 247 /** 248 * Write the rrect into the specified buffer. This is guaranteed to always 249 * write kSizeInMemory bytes, and that value is guaranteed to always be 250 * a multiple of 4. Return kSizeInMemory. 251 */ 252 size_t writeToMemory(void* buffer) const; 253 254 /** 255 * Reads the rrect from the specified buffer 256 * 257 * If the specified buffer is large enough, this will read kSizeInMemory bytes, 258 * and that value is guaranteed to always be a multiple of 4. 259 * 260 * @param buffer Memory to read from 261 * @param length Amount of memory available in the buffer 262 * @return number of bytes read (must be a multiple of 4) or 263 * 0 if there was not enough memory available 264 */ 265 size_t readFromMemory(const void* buffer, size_t length); 266 267 /** 268 * Transform by the specified matrix, and put the result in dst. 269 * 270 * @param matrix SkMatrix specifying the transform. Must only contain 271 * scale and/or translate, or this call will fail. 272 * @param dst SkRRect to store the result. It is an error to use this, 273 * which would make this function no longer const. 274 * @return true on success, false on failure. If false, dst is unmodified. 275 */ 276 bool transform(const SkMatrix& matrix, SkRRect* dst) const; 277 278private: 279 SkRect fRect; 280 // Radii order is UL, UR, LR, LL. Use Corner enum to index into fRadii[] 281 SkVector fRadii[4]; 282 mutable Type fType; 283 // TODO: add padding so we can use memcpy for flattening and not copy 284 // uninitialized data 285 286 void computeType() const; 287 bool checkCornerContainment(SkScalar x, SkScalar y) const; 288 289 // to access fRadii directly 290 friend class SkPath; 291}; 292 293#endif 294