reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2006 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef SkMatrix_DEFINED |
| 18 | #define SkMatrix_DEFINED |
| 19 | |
| 20 | #include "SkRect.h" |
| 21 | |
| 22 | class SkString; |
| 23 | |
| 24 | /** \class SkMatrix |
| 25 | |
| 26 | The SkMatrix class holds a 3x3 matrix for transforming coordinates. |
| 27 | SkMatrix does not have a constructor, so it must be explicitly initialized |
| 28 | using either reset() - to construct an identity matrix, or one of the set |
| 29 | functions (e.g. setTranslate, setRotate, etc.). |
| 30 | */ |
| 31 | class SkMatrix { |
| 32 | public: |
| 33 | /** Enum of bit fields for the mask return by getType(). |
| 34 | Use this to identify the complexity of the matrix. |
| 35 | */ |
| 36 | enum TypeMask { |
| 37 | kIdentity_Mask = 0, |
| 38 | kTranslate_Mask = 0x01, //!< set if the matrix has translation |
| 39 | kScale_Mask = 0x02, //!< set if the matrix has X or Y scale |
| 40 | kAffine_Mask = 0x04, //!< set if the matrix skews or rotates |
| 41 | kPerspective_Mask = 0x08 //!< set if the matrix is in perspective |
| 42 | }; |
| 43 | |
| 44 | /** Returns a mask bitfield describing the types of transformations |
| 45 | that the matrix will perform. This information is used by routines |
| 46 | like mapPoints, to optimize its inner loops to only perform as much |
| 47 | arithmetic as is necessary. |
| 48 | */ |
| 49 | TypeMask getType() const { |
| 50 | if (fTypeMask & kUnknown_Mask) { |
| 51 | fTypeMask = this->computeTypeMask(); |
| 52 | } |
| 53 | // only return the public masks |
| 54 | return (TypeMask)(fTypeMask & 0xF); |
| 55 | } |
| 56 | |
| 57 | /** Returns true if the matrix is identity. |
| 58 | */ |
| 59 | bool isIdentity() const { |
| 60 | return this->getType() == 0; |
| 61 | } |
| 62 | |
| 63 | /** Returns true if will map a rectangle to another rectangle. This can be |
| 64 | true if the matrix is identity, scale-only, or rotates a multiple of |
| 65 | 90 degrees. |
| 66 | */ |
| 67 | bool rectStaysRect() const { |
| 68 | if (fTypeMask & kUnknown_Mask) { |
| 69 | fTypeMask = this->computeTypeMask(); |
| 70 | } |
| 71 | return (fTypeMask & kRectStaysRect_Mask) != 0; |
| 72 | } |
| 73 | |
| 74 | enum { |
| 75 | kMScaleX, |
| 76 | kMSkewX, |
| 77 | kMTransX, |
| 78 | kMSkewY, |
| 79 | kMScaleY, |
| 80 | kMTransY, |
| 81 | kMPersp0, |
| 82 | kMPersp1, |
| 83 | kMPersp2 |
| 84 | }; |
| 85 | |
| 86 | SkScalar operator[](int index) const { |
| 87 | SkASSERT((unsigned)index < 9); |
| 88 | return fMat[index]; |
| 89 | } |
| 90 | |
| 91 | SkScalar get(int index) const { |
| 92 | SkASSERT((unsigned)index < 9); |
| 93 | return fMat[index]; |
| 94 | } |
| 95 | |
| 96 | SkScalar getScaleX() const { return fMat[kMScaleX]; } |
| 97 | SkScalar getScaleY() const { return fMat[kMScaleY]; } |
| 98 | SkScalar getSkewY() const { return fMat[kMSkewY]; } |
| 99 | SkScalar getSkewX() const { return fMat[kMSkewX]; } |
| 100 | SkScalar getTranslateX() const { return fMat[kMTransX]; } |
| 101 | SkScalar getTranslateY() const { return fMat[kMTransY]; } |
| 102 | SkScalar getPerspX() const { return fMat[kMPersp0]; } |
| 103 | SkScalar getPerspY() const { return fMat[kMPersp1]; } |
| 104 | |
| 105 | void set(int index, SkScalar value) { |
| 106 | SkASSERT((unsigned)index < 9); |
| 107 | fMat[index] = value; |
| 108 | this->setTypeMask(kUnknown_Mask); |
| 109 | } |
| 110 | |
| 111 | void setScaleX(SkScalar v) { this->set(kMScaleX, v); } |
| 112 | void setScaleY(SkScalar v) { this->set(kMScaleY, v); } |
| 113 | void setSkewY(SkScalar v) { this->set(kMSkewY, v); } |
| 114 | void setSkewX(SkScalar v) { this->set(kMSkewX, v); } |
| 115 | void setTranslateX(SkScalar v) { this->set(kMTransX, v); } |
| 116 | void setTranslateY(SkScalar v) { this->set(kMTransY, v); } |
| 117 | void setPerspX(SkScalar v) { this->set(kMPersp0, v); } |
| 118 | void setPerspY(SkScalar v) { this->set(kMPersp1, v); } |
| 119 | |
| 120 | /** Set the matrix to identity |
| 121 | */ |
| 122 | void reset(); |
| 123 | |
| 124 | /** Set the matrix to translate by (dx, dy). |
| 125 | */ |
| 126 | void setTranslate(SkScalar dx, SkScalar dy); |
| 127 | /** Set the matrix to scale by sx and sy, with a pivot point at (px, py). |
| 128 | The pivot point is the coordinate that should remain unchanged by the |
| 129 | specified transformation. |
| 130 | */ |
| 131 | void setScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py); |
| 132 | /** Set the matrix to scale by sx and sy. |
| 133 | */ |
| 134 | void setScale(SkScalar sx, SkScalar sy); |
| 135 | /** Set the matrix to rotate by the specified number of degrees, with a |
| 136 | pivot point at (px, py). The pivot point is the coordinate that should |
| 137 | remain unchanged by the specified transformation. |
| 138 | */ |
| 139 | void setRotate(SkScalar degrees, SkScalar px, SkScalar py); |
| 140 | /** Set the matrix to rotate about (0,0) by the specified number of degrees. |
| 141 | */ |
| 142 | void setRotate(SkScalar degrees); |
| 143 | /** Set the matrix to rotate by the specified sine and cosine values, with |
| 144 | a pivot point at (px, py). The pivot point is the coordinate that |
| 145 | should remain unchanged by the specified transformation. |
| 146 | */ |
| 147 | void setSinCos(SkScalar sinValue, SkScalar cosValue, |
| 148 | SkScalar px, SkScalar py); |
| 149 | /** Set the matrix to rotate by the specified sine and cosine values. |
| 150 | */ |
| 151 | void setSinCos(SkScalar sinValue, SkScalar cosValue); |
| 152 | /** Set the matrix to skew by sx and sy, with a pivot point at (px, py). |
| 153 | The pivot point is the coordinate that should remain unchanged by the |
| 154 | specified transformation. |
| 155 | */ |
| 156 | void setSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py); |
| 157 | /** Set the matrix to skew by sx and sy. |
| 158 | */ |
| 159 | void setSkew(SkScalar kx, SkScalar ky); |
| 160 | /** Set the matrix to the concatenation of the two specified matrices, |
| 161 | returning true if the the result can be represented. Either of the |
| 162 | two matrices may also be the target matrix. *this = a * b; |
| 163 | */ |
| 164 | bool setConcat(const SkMatrix& a, const SkMatrix& b); |
| 165 | |
| 166 | /** Preconcats the matrix with the specified translation. |
| 167 | M' = M * T(dx, dy) |
| 168 | */ |
| 169 | bool preTranslate(SkScalar dx, SkScalar dy); |
| 170 | /** Preconcats the matrix with the specified scale. |
| 171 | M' = M * S(sx, sy, px, py) |
| 172 | */ |
| 173 | bool preScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py); |
| 174 | /** Preconcats the matrix with the specified scale. |
| 175 | M' = M * S(sx, sy) |
| 176 | */ |
| 177 | bool preScale(SkScalar sx, SkScalar sy); |
| 178 | /** Preconcats the matrix with the specified rotation. |
| 179 | M' = M * R(degrees, px, py) |
| 180 | */ |
| 181 | bool preRotate(SkScalar degrees, SkScalar px, SkScalar py); |
| 182 | /** Preconcats the matrix with the specified rotation. |
| 183 | M' = M * R(degrees) |
| 184 | */ |
| 185 | bool preRotate(SkScalar degrees); |
| 186 | /** Preconcats the matrix with the specified skew. |
| 187 | M' = M * K(kx, ky, px, py) |
| 188 | */ |
| 189 | bool preSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py); |
| 190 | /** Preconcats the matrix with the specified skew. |
| 191 | M' = M * K(kx, ky) |
| 192 | */ |
| 193 | bool preSkew(SkScalar kx, SkScalar ky); |
| 194 | /** Preconcats the matrix with the specified matrix. |
| 195 | M' = M * other |
| 196 | */ |
| 197 | bool preConcat(const SkMatrix& other); |
| 198 | |
| 199 | /** Postconcats the matrix with the specified translation. |
| 200 | M' = T(dx, dy) * M |
| 201 | */ |
| 202 | bool postTranslate(SkScalar dx, SkScalar dy); |
| 203 | /** Postconcats the matrix with the specified scale. |
| 204 | M' = S(sx, sy, px, py) * M |
| 205 | */ |
| 206 | bool postScale(SkScalar sx, SkScalar sy, SkScalar px, SkScalar py); |
| 207 | /** Postconcats the matrix with the specified scale. |
| 208 | M' = S(sx, sy) * M |
| 209 | */ |
| 210 | bool postScale(SkScalar sx, SkScalar sy); |
| 211 | /** Postconcats the matrix by dividing it by the specified integers. |
| 212 | M' = S(1/divx, 1/divy, 0, 0) * M |
| 213 | */ |
| 214 | bool postIDiv(int divx, int divy); |
| 215 | /** Postconcats the matrix with the specified rotation. |
| 216 | M' = R(degrees, px, py) * M |
| 217 | */ |
| 218 | bool postRotate(SkScalar degrees, SkScalar px, SkScalar py); |
| 219 | /** Postconcats the matrix with the specified rotation. |
| 220 | M' = R(degrees) * M |
| 221 | */ |
| 222 | bool postRotate(SkScalar degrees); |
| 223 | /** Postconcats the matrix with the specified skew. |
| 224 | M' = K(kx, ky, px, py) * M |
| 225 | */ |
| 226 | bool postSkew(SkScalar kx, SkScalar ky, SkScalar px, SkScalar py); |
| 227 | /** Postconcats the matrix with the specified skew. |
| 228 | M' = K(kx, ky) * M |
| 229 | */ |
| 230 | bool postSkew(SkScalar kx, SkScalar ky); |
| 231 | /** Postconcats the matrix with the specified matrix. |
| 232 | M' = other * M |
| 233 | */ |
| 234 | bool postConcat(const SkMatrix& other); |
| 235 | |
| 236 | enum ScaleToFit { |
| 237 | /** |
| 238 | * Scale in X and Y independently, so that src matches dst exactly. |
| 239 | * This may change the aspect ratio of the src. |
| 240 | */ |
| 241 | kFill_ScaleToFit, |
| 242 | /** |
| 243 | * Compute a scale that will maintain the original src aspect ratio, |
| 244 | * but will also ensure that src fits entirely inside dst. At least one |
| 245 | * axis (X or Y) will fit exactly. kStart aligns the result to the |
| 246 | * left and top edges of dst. |
| 247 | */ |
| 248 | kStart_ScaleToFit, |
| 249 | /** |
| 250 | * Compute a scale that will maintain the original src aspect ratio, |
| 251 | * but will also ensure that src fits entirely inside dst. At least one |
| 252 | * axis (X or Y) will fit exactly. The result is centered inside dst. |
| 253 | */ |
| 254 | kCenter_ScaleToFit, |
| 255 | /** |
| 256 | * Compute a scale that will maintain the original src aspect ratio, |
| 257 | * but will also ensure that src fits entirely inside dst. At least one |
| 258 | * axis (X or Y) will fit exactly. kEnd aligns the result to the |
| 259 | * right and bottom edges of dst. |
| 260 | */ |
| 261 | kEnd_ScaleToFit |
| 262 | }; |
| 263 | |
| 264 | /** Set the matrix to the scale and translate values that map the source |
| 265 | rectangle to the destination rectangle, returning true if the the result |
| 266 | can be represented. |
| 267 | @param src the source rectangle to map from. |
| 268 | @param dst the destination rectangle to map to. |
| 269 | @param stf the ScaleToFit option |
| 270 | @return true if the matrix can be represented by the rectangle mapping. |
| 271 | */ |
| 272 | bool setRectToRect(const SkRect& src, const SkRect& dst, ScaleToFit stf); |
| 273 | |
| 274 | /** Set the matrix such that the specified src points would map to the |
| 275 | specified dst points. count must be within [0..4]. |
| 276 | @param src The array of src points |
| 277 | @param dst The array of dst points |
| 278 | @param count The number of points to use for the transformation |
| 279 | @return true if the matrix was set to the specified transformation |
| 280 | */ |
| 281 | bool setPolyToPoly(const SkPoint src[], const SkPoint dst[], int count); |
| 282 | |
| 283 | /** If this matrix can be inverted, return true and if inverse is not null, |
| 284 | set inverse to be the inverse of this matrix. If this matrix cannot be |
| 285 | inverted, ignore inverse and return false |
| 286 | */ |
| 287 | bool invert(SkMatrix* inverse) const; |
| 288 | |
| 289 | /** Apply this matrix to the array of points specified by src, and write |
| 290 | the transformed points into the array of points specified by dst. |
| 291 | dst[] = M * src[] |
| 292 | @param dst Where the transformed coordinates are written. It must |
| 293 | contain at least count entries |
| 294 | @param src The original coordinates that are to be transformed. It |
| 295 | must contain at least count entries |
| 296 | @param count The number of points in src to read, and then transform |
| 297 | into dst. |
| 298 | */ |
| 299 | void mapPoints(SkPoint dst[], const SkPoint src[], int count) const; |
| 300 | |
| 301 | /** Apply this matrix to the array of points, overwriting it with the |
| 302 | transformed values. |
| 303 | dst[] = M * pts[] |
| 304 | @param pts The points to be transformed. It must contain at least |
| 305 | count entries |
| 306 | @param count The number of points in pts. |
| 307 | */ |
| 308 | void mapPoints(SkPoint pts[], int count) const { |
| 309 | this->mapPoints(pts, pts, count); |
| 310 | } |
| 311 | |
| 312 | void mapXY(SkScalar x, SkScalar y, SkPoint* result) const { |
| 313 | SkASSERT(result); |
| 314 | this->getMapXYProc()(*this, x, y, result); |
| 315 | } |
| 316 | |
| 317 | /** Apply this matrix to the array of vectors specified by src, and write |
| 318 | the transformed vectors into the array of vectors specified by dst. |
| 319 | This is similar to mapPoints, but ignores any translation in the matrix. |
| 320 | @param dst Where the transformed coordinates are written. It must |
| 321 | contain at least count entries |
| 322 | @param src The original coordinates that are to be transformed. It |
| 323 | must contain at least count entries |
| 324 | @param count The number of vectors in src to read, and then transform |
| 325 | into dst. |
| 326 | */ |
| 327 | void mapVectors(SkVector dst[], const SkVector src[], int count) const; |
| 328 | |
| 329 | /** Apply this matrix to the array of vectors specified by src, and write |
| 330 | the transformed vectors into the array of vectors specified by dst. |
| 331 | This is similar to mapPoints, but ignores any translation in the matrix. |
| 332 | @param vecs The vectors to be transformed. It must contain at least |
| 333 | count entries |
| 334 | @param count The number of vectors in vecs. |
| 335 | */ |
| 336 | void mapVectors(SkVector vecs[], int count) const { |
| 337 | this->mapVectors(vecs, vecs, count); |
| 338 | } |
| 339 | |
| 340 | /** Apply this matrix to the src rectangle, and write the transformed |
| 341 | rectangle into dst. This is accomplished by transforming the 4 corners |
| 342 | of src, and then setting dst to the bounds of those points. |
| 343 | @param dst Where the transformed rectangle is written. |
| 344 | @param src The original rectangle to be transformed. |
| 345 | @return the result of calling rectStaysRect() |
| 346 | */ |
| 347 | bool mapRect(SkRect* dst, const SkRect& src) const; |
| 348 | |
| 349 | /** Apply this matrix to the rectangle, and write the transformed rectangle |
| 350 | back into it. This is accomplished by transforming the 4 corners of |
| 351 | rect, and then setting it to the bounds of those points |
| 352 | @param rect The rectangle to transform. |
| 353 | @return the result of calling rectStaysRect() |
| 354 | */ |
| 355 | bool mapRect(SkRect* rect) const { |
| 356 | return this->mapRect(rect, *rect); |
| 357 | } |
| 358 | |
| 359 | /** Return the mean radius of a circle after it has been mapped by |
| 360 | this matrix. NOTE: in perspective this value assumes the circle |
| 361 | has its center at the origin. |
| 362 | */ |
| 363 | SkScalar mapRadius(SkScalar radius) const; |
| 364 | |
| 365 | typedef void (*MapXYProc)(const SkMatrix& mat, SkScalar x, SkScalar y, |
| 366 | SkPoint* result); |
| 367 | |
| 368 | static MapXYProc GetMapXYProc(TypeMask mask) { |
| 369 | SkASSERT((mask & ~kAllMasks) == 0); |
| 370 | return gMapXYProcs[mask & kAllMasks]; |
| 371 | } |
| 372 | |
| 373 | MapXYProc getMapXYProc() const { |
| 374 | return GetMapXYProc(this->getType()); |
| 375 | } |
| 376 | |
| 377 | typedef void (*MapPtsProc)(const SkMatrix& mat, SkPoint dst[], |
| 378 | const SkPoint src[], int count); |
| 379 | |
| 380 | static MapPtsProc GetMapPtsProc(TypeMask mask) { |
| 381 | SkASSERT((mask & ~kAllMasks) == 0); |
| 382 | return gMapPtsProcs[mask & kAllMasks]; |
| 383 | } |
| 384 | |
| 385 | MapPtsProc getMapPtsProc() const { |
| 386 | return GetMapPtsProc(this->getType()); |
| 387 | } |
| 388 | |
| 389 | /** If the matrix can be stepped in X (not complex perspective) |
| 390 | then return true and if step[XY] is not null, return the step[XY] value. |
| 391 | If it cannot, return false and ignore step. |
| 392 | */ |
| 393 | bool fixedStepInX(SkScalar y, SkFixed* stepX, SkFixed* stepY) const; |
| 394 | |
| 395 | friend bool operator==(const SkMatrix& a, const SkMatrix& b) { |
| 396 | return memcmp(a.fMat, b.fMat, sizeof(a.fMat)) == 0; |
| 397 | } |
| 398 | |
| 399 | friend bool operator!=(const SkMatrix& a, const SkMatrix& b) { |
| 400 | return memcmp(a.fMat, b.fMat, sizeof(a.fMat)) != 0; |
| 401 | } |
| 402 | |
| 403 | void dump() const; |
| 404 | void toDumpString(SkString*) const; |
| 405 | |
| 406 | #ifdef SK_DEBUG |
| 407 | /** @cond UNIT_TEST */ |
| 408 | |
| 409 | static void UnitTest(); |
| 410 | /** @endcond */ |
| 411 | #endif |
| 412 | |
| 413 | private: |
| 414 | enum { |
| 415 | /** Set if the matrix will map a rectangle to another rectangle. This |
| 416 | can be true if the matrix is scale-only, or rotates a multiple of |
| 417 | 90 degrees. This bit is not set if the matrix is identity. |
| 418 | |
| 419 | This bit will be set on identity matrices |
| 420 | */ |
| 421 | kRectStaysRect_Mask = 0x10, |
| 422 | |
| 423 | kUnknown_Mask = 0x80, |
| 424 | |
| 425 | kAllMasks = kTranslate_Mask | |
| 426 | kScale_Mask | |
| 427 | kAffine_Mask | |
| 428 | kPerspective_Mask | |
| 429 | kRectStaysRect_Mask |
| 430 | }; |
| 431 | |
| 432 | SkScalar fMat[9]; |
| 433 | mutable uint8_t fTypeMask; |
| 434 | |
| 435 | uint8_t computeTypeMask() const; |
| 436 | |
| 437 | void setTypeMask(int mask) { |
| 438 | // allow kUnknown or a valid mask |
| 439 | SkASSERT(kUnknown_Mask == mask || (mask & kAllMasks) == mask); |
| 440 | fTypeMask = SkToU8(mask); |
| 441 | } |
| 442 | |
| 443 | void clearTypeMask(int mask) { |
| 444 | // only allow a valid mask |
| 445 | SkASSERT((mask & kAllMasks) == mask); |
| 446 | fTypeMask &= ~mask; |
| 447 | } |
| 448 | |
| 449 | static bool Poly2Proc(const SkPoint[], SkMatrix*, const SkPoint& scale); |
| 450 | static bool Poly3Proc(const SkPoint[], SkMatrix*, const SkPoint& scale); |
| 451 | static bool Poly4Proc(const SkPoint[], SkMatrix*, const SkPoint& scale); |
| 452 | |
| 453 | static void Identity_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 454 | static void Trans_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 455 | static void Scale_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 456 | static void ScaleTrans_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 457 | static void Rot_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 458 | static void RotTrans_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 459 | static void Persp_xy(const SkMatrix&, SkScalar, SkScalar, SkPoint*); |
| 460 | |
| 461 | static const MapXYProc gMapXYProcs[]; |
| 462 | |
| 463 | static void Identity_pts(const SkMatrix&, SkPoint[], const SkPoint[], int); |
| 464 | static void Trans_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], int); |
| 465 | static void Scale_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], int); |
| 466 | static void ScaleTrans_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], |
| 467 | int count); |
| 468 | static void Rot_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], int); |
| 469 | static void RotTrans_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], |
| 470 | int count); |
| 471 | static void Persp_pts(const SkMatrix&, SkPoint dst[], const SkPoint[], int); |
| 472 | |
| 473 | static const MapPtsProc gMapPtsProcs[]; |
| 474 | |
| 475 | friend class SkPerspIter; |
| 476 | }; |
| 477 | |
| 478 | #endif |
| 479 | |