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 SkPoint_DEFINED |
| 18 | #define SkPoint_DEFINED |
| 19 | |
| 20 | #include "SkMath.h" |
| 21 | #include "SkScalar.h" |
| 22 | |
| 23 | /** \struct SkIPoint |
| 24 | |
| 25 | SkIPoint holds two 32 bit integer coordinates |
| 26 | */ |
| 27 | struct SkIPoint { |
| 28 | int32_t fX, fY; |
| 29 | |
| 30 | /** Set the x and y values of the point. */ |
| 31 | void set(int32_t x, int32_t y) { fX = x; fY = y; } |
| 32 | |
| 33 | /** Rotate the point clockwise, writing the new point into dst |
| 34 | It is legal for dst == this |
| 35 | */ |
| 36 | void rotateCW(SkIPoint* dst) const; |
| 37 | |
| 38 | /** Rotate the point clockwise, writing the new point back into the point |
| 39 | */ |
| 40 | |
| 41 | void rotateCW() { this->rotateCW(this); } |
| 42 | |
| 43 | /** Rotate the point counter-clockwise, writing the new point into dst. |
| 44 | It is legal for dst == this |
| 45 | */ |
| 46 | void rotateCCW(SkIPoint* dst) const; |
| 47 | |
| 48 | /** Rotate the point counter-clockwise, writing the new point back into |
| 49 | the point |
| 50 | */ |
| 51 | void rotateCCW() { this->rotateCCW(this); } |
| 52 | |
| 53 | /** Negate the X and Y coordinates of the point. |
| 54 | */ |
| 55 | void negate() { fX = -fX; fY = -fY; } |
| 56 | |
| 57 | /** Return a new point whose X and Y coordinates are the negative of the |
| 58 | original point's |
| 59 | */ |
| 60 | SkIPoint operator-() const { |
| 61 | SkIPoint neg; |
| 62 | neg.fX = -fX; |
| 63 | neg.fY = -fY; |
| 64 | return neg; |
| 65 | } |
| 66 | |
| 67 | /** Add v's coordinates to this point's */ |
| 68 | void operator+=(const SkIPoint& v) { |
| 69 | fX += v.fX; |
| 70 | fY += v.fY; |
| 71 | } |
| 72 | |
| 73 | /** Subtract v's coordinates from this point's */ |
| 74 | void operator-=(const SkIPoint& v) { |
| 75 | fX -= v.fX; |
| 76 | fY -= v.fY; |
| 77 | } |
| 78 | |
| 79 | /** Returns true if the point's coordinates equal (x,y) */ |
| 80 | bool equals(int32_t x, int32_t y) const { |
| 81 | return fX == x && fY == y; |
| 82 | } |
| 83 | |
| 84 | friend bool operator==(const SkIPoint& a, const SkIPoint& b) { |
| 85 | return a.fX == b.fX && a.fY == b.fY; |
| 86 | } |
| 87 | |
| 88 | friend bool operator!=(const SkIPoint& a, const SkIPoint& b) { |
| 89 | return a.fX != b.fX || a.fY != b.fY; |
| 90 | } |
| 91 | |
| 92 | /** Returns a new point whose coordinates are the difference between |
| 93 | a and b (i.e. a - b) |
| 94 | */ |
| 95 | friend SkIPoint operator-(const SkIPoint& a, const SkIPoint& b) { |
| 96 | SkIPoint v; |
| 97 | v.set(a.fX - b.fX, a.fY - b.fY); |
| 98 | return v; |
| 99 | } |
| 100 | |
| 101 | /** Returns a new point whose coordinates are the sum of a and b (a + b) |
| 102 | */ |
| 103 | friend SkIPoint operator+(const SkIPoint& a, const SkIPoint& b) { |
| 104 | SkIPoint v; |
| 105 | v.set(a.fX + b.fX, a.fY + b.fY); |
| 106 | return v; |
| 107 | } |
| 108 | |
| 109 | /** Returns the dot product of a and b, treating them as 2D vectors |
| 110 | */ |
| 111 | static int32_t DotProduct(const SkIPoint& a, const SkIPoint& b) { |
| 112 | return a.fX * b.fX + a.fY * b.fY; |
| 113 | } |
| 114 | |
| 115 | /** Returns the cross product of a and b, treating them as 2D vectors |
| 116 | */ |
| 117 | static int32_t CrossProduct(const SkIPoint& a, const SkIPoint& b) { |
| 118 | return a.fX * b.fY - a.fY * b.fX; |
| 119 | } |
| 120 | }; |
| 121 | |
| 122 | struct SkPoint { |
| 123 | SkScalar fX, fY; |
| 124 | |
| 125 | /** Set the point's X and Y coordinates */ |
| 126 | void set(SkScalar x, SkScalar y) { fX = x; fY = y; } |
| 127 | |
| 128 | /** Set the point's X and Y coordinates by automatically promoting (x,y) to |
| 129 | SkScalar values. |
| 130 | */ |
| 131 | void iset(int32_t x, int32_t y) { |
| 132 | fX = SkIntToScalar(x); |
| 133 | fY = SkIntToScalar(y); |
| 134 | } |
| 135 | |
| 136 | /** Set the point's X and Y coordinates by automatically promoting p's |
| 137 | coordinates to SkScalar values. |
| 138 | */ |
| 139 | void iset(const SkIPoint& p) { |
| 140 | fX = SkIntToScalar(p.fX); |
| 141 | fY = SkIntToScalar(p.fY); |
| 142 | } |
| 143 | |
| 144 | /** Return the euclidian distance from (0,0) to the point |
| 145 | */ |
| 146 | SkScalar length() const { return SkPoint::Length(fX, fY); } |
| 147 | |
| 148 | /** Set the point (vector) to be unit-length in the same direction as it |
| 149 | currently is, and return its old length. If the old length is |
| 150 | degenerately small (nearly zero), do nothing and return false, otherwise |
| 151 | return true. |
| 152 | */ |
| 153 | bool normalize(); |
| 154 | |
| 155 | /** Set the point (vector) to be unit-length in the same direction as the |
| 156 | x,y params. If the vector (x,y) has a degenerate length (i.e. nearly 0) |
| 157 | then return false and do nothing, otherwise return true. |
| 158 | */ |
| 159 | bool setNormalize(SkScalar x, SkScalar y); |
| 160 | |
| 161 | /** Scale the point (vector) to have the specified length, and return that |
| 162 | length. If the original length is degenerately small (nearly zero), |
| 163 | do nothing and return false, otherwise return true. |
| 164 | */ |
| 165 | bool setLength(SkScalar length); |
| 166 | |
| 167 | /** Set the point (vector) to have the specified length in the same |
| 168 | direction as (x,y). If the vector (x,y) has a degenerate length |
| 169 | (i.e. nearly 0) then return false and do nothing, otherwise return true. |
| 170 | */ |
| 171 | bool setLength(SkScalar x, SkScalar y, SkScalar length); |
| 172 | |
| 173 | /** Scale the point's coordinates by scale, writing the answer into dst. |
| 174 | It is legal for dst == this. |
| 175 | */ |
| 176 | void scale(SkScalar scale, SkPoint* dst) const; |
| 177 | |
| 178 | /** Scale the point's coordinates by scale, writing the answer back into |
| 179 | the point. |
| 180 | */ |
| 181 | void scale(SkScalar scale) { this->scale(scale, this); } |
| 182 | |
| 183 | /** Rotate the point clockwise by 90 degrees, writing the answer into dst. |
| 184 | It is legal for dst == this. |
| 185 | */ |
| 186 | void rotateCW(SkPoint* dst) const; |
| 187 | |
| 188 | /** Rotate the point clockwise by 90 degrees, writing the answer back into |
| 189 | the point. |
| 190 | */ |
| 191 | void rotateCW() { this->rotateCW(this); } |
| 192 | |
| 193 | /** Rotate the point counter-clockwise by 90 degrees, writing the answer |
| 194 | into dst. It is legal for dst == this. |
| 195 | */ |
| 196 | void rotateCCW(SkPoint* dst) const; |
| 197 | |
| 198 | /** Rotate the point counter-clockwise by 90 degrees, writing the answer |
| 199 | back into the point. |
| 200 | */ |
| 201 | void rotateCCW() { this->rotateCCW(this); } |
| 202 | |
| 203 | /** Negate the point's coordinates |
| 204 | */ |
| 205 | void negate() { |
| 206 | fX = -fX; |
| 207 | fY = -fY; |
| 208 | } |
| 209 | |
| 210 | /** Returns a new point whose coordinates are the negative of the point's |
| 211 | */ |
| 212 | SkPoint operator-() const { |
| 213 | SkPoint neg; |
| 214 | neg.fX = -fX; |
| 215 | neg.fY = -fY; |
| 216 | return neg; |
| 217 | } |
| 218 | |
| 219 | /** Add v's coordinates to the point's |
| 220 | */ |
| 221 | void operator+=(const SkPoint& v) { |
| 222 | fX += v.fX; |
| 223 | fY += v.fY; |
| 224 | } |
| 225 | |
| 226 | /** Subtract v's coordinates from the point's |
| 227 | */ |
| 228 | void operator-=(const SkPoint& v) { |
| 229 | fX -= v.fX; |
| 230 | fY -= v.fY; |
| 231 | } |
| 232 | |
| 233 | /** Returns true if the point's coordinates equal (x,y) |
| 234 | */ |
| 235 | bool equals(SkScalar x, SkScalar y) const { return fX == x && fY == y; } |
| 236 | |
| 237 | friend bool operator==(const SkPoint& a, const SkPoint& b) { |
| 238 | return a.fX == b.fX && a.fY == b.fY; |
| 239 | } |
| 240 | |
| 241 | friend bool operator!=(const SkPoint& a, const SkPoint& b) { |
| 242 | return a.fX != b.fX || a.fY != b.fY; |
| 243 | } |
| 244 | |
| 245 | /** Returns a new point whose coordinates are the difference between |
| 246 | a's and b's (a - b) |
| 247 | */ |
| 248 | friend SkPoint operator-(const SkPoint& a, const SkPoint& b) { |
| 249 | SkPoint v; |
| 250 | v.set(a.fX - b.fX, a.fY - b.fY); |
| 251 | return v; |
| 252 | } |
| 253 | |
| 254 | /** Returns a new point whose coordinates are the sum of a's and b's (a + b) |
| 255 | */ |
| 256 | friend SkPoint operator+(const SkPoint& a, const SkPoint& b) { |
| 257 | SkPoint v; |
| 258 | v.set(a.fX + b.fX, a.fY + b.fY); |
| 259 | return v; |
| 260 | } |
| 261 | |
| 262 | /** Returns the euclidian distance from (0,0) to (x,y) |
| 263 | */ |
| 264 | static SkScalar Length(SkScalar x, SkScalar y); |
| 265 | |
| 266 | /** Returns the euclidian distance between a and b |
| 267 | */ |
| 268 | static SkScalar Distance(const SkPoint& a, const SkPoint& b) { |
| 269 | return Length(a.fX - b.fX, a.fY - b.fY); |
| 270 | } |
| 271 | |
| 272 | /** Returns the dot product of a and b, treating them as 2D vectors |
| 273 | */ |
| 274 | static SkScalar DotProduct(const SkPoint& a, const SkPoint& b) { |
| 275 | return SkScalarMul(a.fX, b.fX) + SkScalarMul(a.fY, b.fY); |
| 276 | } |
| 277 | |
| 278 | /** Returns the cross product of a and b, treating them as 2D vectors |
| 279 | */ |
| 280 | static SkScalar CrossProduct(const SkPoint& a, const SkPoint& b) { |
| 281 | return SkScalarMul(a.fX, b.fY) - SkScalarMul(a.fY, b.fX); |
| 282 | } |
| 283 | }; |
| 284 | |
| 285 | typedef SkPoint SkVector; |
| 286 | |
| 287 | #endif |
| 288 | |