1 /* $NetBSD: drm_rect.c,v 1.4 2021/12/19 01:15:00 riastradh Exp $ */ 2 3 /* 4 * Copyright (C) 2011-2013 Intel Corporation 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 * SOFTWARE. 24 */ 25 26 #include <sys/cdefs.h> 27 __KERNEL_RCSID(0, "$NetBSD: drm_rect.c,v 1.4 2021/12/19 01:15:00 riastradh Exp $"); 28 29 #include <linux/errno.h> 30 #include <linux/export.h> 31 #include <linux/kernel.h> 32 #include <linux/math64.h> 33 34 #include <drm/drm_mode.h> 35 #include <drm/drm_print.h> 36 #include <drm/drm_rect.h> 37 38 /** 39 * drm_rect_intersect - intersect two rectangles 40 * @r1: first rectangle 41 * @r2: second rectangle 42 * 43 * Calculate the intersection of rectangles @r1 and @r2. 44 * @r1 will be overwritten with the intersection. 45 * 46 * RETURNS: 47 * %true if rectangle @r1 is still visible after the operation, 48 * %false otherwise. 49 */ 50 bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2) 51 { 52 r1->x1 = max(r1->x1, r2->x1); 53 r1->y1 = max(r1->y1, r2->y1); 54 r1->x2 = min(r1->x2, r2->x2); 55 r1->y2 = min(r1->y2, r2->y2); 56 57 return drm_rect_visible(r1); 58 } 59 EXPORT_SYMBOL(drm_rect_intersect); 60 61 static u32 clip_scaled(int src, int dst, int *clip) 62 { 63 u64 tmp; 64 65 if (dst == 0) 66 return 0; 67 68 /* Only clip what we have. Keeps the result bounded. */ 69 *clip = min(*clip, dst); 70 71 tmp = mul_u32_u32(src, dst - *clip); 72 73 /* 74 * Round toward 1.0 when clipping so that we don't accidentally 75 * change upscaling to downscaling or vice versa. 76 */ 77 if (src < (dst << 16)) 78 return DIV_ROUND_UP_ULL(tmp, dst); 79 else 80 return DIV_ROUND_DOWN_ULL(tmp, dst); 81 } 82 83 /** 84 * drm_rect_clip_scaled - perform a scaled clip operation 85 * @src: source window rectangle 86 * @dst: destination window rectangle 87 * @clip: clip rectangle 88 * 89 * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the 90 * the corresponding amounts, retaining the vertical and horizontal scaling 91 * factors from @src to @dst. 92 * 93 * RETURNS: 94 * 95 * %true if rectangle @dst is still visible after being clipped, 96 * %false otherwise. 97 */ 98 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst, 99 const struct drm_rect *clip) 100 { 101 int diff; 102 103 diff = clip->x1 - dst->x1; 104 if (diff > 0) { 105 u32 new_src_w = clip_scaled(drm_rect_width(src), 106 drm_rect_width(dst), &diff); 107 108 src->x1 = src->x2 - new_src_w; 109 dst->x1 += diff; 110 } 111 diff = clip->y1 - dst->y1; 112 if (diff > 0) { 113 u32 new_src_h = clip_scaled(drm_rect_height(src), 114 drm_rect_height(dst), &diff); 115 116 src->y1 = src->y2 - new_src_h; 117 dst->y1 += diff; 118 } 119 diff = dst->x2 - clip->x2; 120 if (diff > 0) { 121 u32 new_src_w = clip_scaled(drm_rect_width(src), 122 drm_rect_width(dst), &diff); 123 124 src->x2 = src->x1 + new_src_w; 125 dst->x2 -= diff; 126 } 127 diff = dst->y2 - clip->y2; 128 if (diff > 0) { 129 u32 new_src_h = clip_scaled(drm_rect_height(src), 130 drm_rect_height(dst), &diff); 131 132 src->y2 = src->y1 + new_src_h; 133 dst->y2 -= diff; 134 } 135 136 return drm_rect_visible(dst); 137 } 138 EXPORT_SYMBOL(drm_rect_clip_scaled); 139 140 static int drm_calc_scale(int src, int dst) 141 { 142 int scale = 0; 143 144 if (WARN_ON(src < 0 || dst < 0)) 145 return -EINVAL; 146 147 if (dst == 0) 148 return 0; 149 150 if (src > (dst << 16)) 151 return DIV_ROUND_UP(src, dst); 152 else 153 scale = src / dst; 154 155 return scale; 156 } 157 158 /** 159 * drm_rect_calc_hscale - calculate the horizontal scaling factor 160 * @src: source window rectangle 161 * @dst: destination window rectangle 162 * @min_hscale: minimum allowed horizontal scaling factor 163 * @max_hscale: maximum allowed horizontal scaling factor 164 * 165 * Calculate the horizontal scaling factor as 166 * (@src width) / (@dst width). 167 * 168 * If the scale is below 1 << 16, round down. If the scale is above 169 * 1 << 16, round up. This will calculate the scale with the most 170 * pessimistic limit calculation. 171 * 172 * RETURNS: 173 * The horizontal scaling factor, or errno of out of limits. 174 */ 175 int drm_rect_calc_hscale(const struct drm_rect *src, 176 const struct drm_rect *dst, 177 int min_hscale, int max_hscale) 178 { 179 int src_w = drm_rect_width(src); 180 int dst_w = drm_rect_width(dst); 181 int hscale = drm_calc_scale(src_w, dst_w); 182 183 if (hscale < 0 || dst_w == 0) 184 return hscale; 185 186 if (hscale < min_hscale || hscale > max_hscale) 187 return -ERANGE; 188 189 return hscale; 190 } 191 EXPORT_SYMBOL(drm_rect_calc_hscale); 192 193 /** 194 * drm_rect_calc_vscale - calculate the vertical scaling factor 195 * @src: source window rectangle 196 * @dst: destination window rectangle 197 * @min_vscale: minimum allowed vertical scaling factor 198 * @max_vscale: maximum allowed vertical scaling factor 199 * 200 * Calculate the vertical scaling factor as 201 * (@src height) / (@dst height). 202 * 203 * If the scale is below 1 << 16, round down. If the scale is above 204 * 1 << 16, round up. This will calculate the scale with the most 205 * pessimistic limit calculation. 206 * 207 * RETURNS: 208 * The vertical scaling factor, or errno of out of limits. 209 */ 210 int drm_rect_calc_vscale(const struct drm_rect *src, 211 const struct drm_rect *dst, 212 int min_vscale, int max_vscale) 213 { 214 int src_h = drm_rect_height(src); 215 int dst_h = drm_rect_height(dst); 216 int vscale = drm_calc_scale(src_h, dst_h); 217 218 if (vscale < 0 || dst_h == 0) 219 return vscale; 220 221 if (vscale < min_vscale || vscale > max_vscale) 222 return -ERANGE; 223 224 return vscale; 225 } 226 EXPORT_SYMBOL(drm_rect_calc_vscale); 227 228 /** 229 * drm_rect_debug_print - print the rectangle information 230 * @prefix: prefix string 231 * @r: rectangle to print 232 * @fixed_point: rectangle is in 16.16 fixed point format 233 */ 234 void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point) 235 { 236 if (fixed_point) 237 DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r)); 238 else 239 DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r)); 240 } 241 EXPORT_SYMBOL(drm_rect_debug_print); 242 243 /** 244 * drm_rect_rotate - Rotate the rectangle 245 * @r: rectangle to be rotated 246 * @width: Width of the coordinate space 247 * @height: Height of the coordinate space 248 * @rotation: Transformation to be applied 249 * 250 * Apply @rotation to the coordinates of rectangle @r. 251 * 252 * @width and @height combined with @rotation define 253 * the location of the new origin. 254 * 255 * @width correcsponds to the horizontal and @height 256 * to the vertical axis of the untransformed coordinate 257 * space. 258 */ 259 void drm_rect_rotate(struct drm_rect *r, 260 int width, int height, 261 unsigned int rotation) 262 { 263 struct drm_rect tmp; 264 265 if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) { 266 tmp = *r; 267 268 if (rotation & DRM_MODE_REFLECT_X) { 269 r->x1 = width - tmp.x2; 270 r->x2 = width - tmp.x1; 271 } 272 273 if (rotation & DRM_MODE_REFLECT_Y) { 274 r->y1 = height - tmp.y2; 275 r->y2 = height - tmp.y1; 276 } 277 } 278 279 switch (rotation & DRM_MODE_ROTATE_MASK) { 280 case DRM_MODE_ROTATE_0: 281 break; 282 case DRM_MODE_ROTATE_90: 283 tmp = *r; 284 r->x1 = tmp.y1; 285 r->x2 = tmp.y2; 286 r->y1 = width - tmp.x2; 287 r->y2 = width - tmp.x1; 288 break; 289 case DRM_MODE_ROTATE_180: 290 tmp = *r; 291 r->x1 = width - tmp.x2; 292 r->x2 = width - tmp.x1; 293 r->y1 = height - tmp.y2; 294 r->y2 = height - tmp.y1; 295 break; 296 case DRM_MODE_ROTATE_270: 297 tmp = *r; 298 r->x1 = height - tmp.y2; 299 r->x2 = height - tmp.y1; 300 r->y1 = tmp.x1; 301 r->y2 = tmp.x2; 302 break; 303 default: 304 break; 305 } 306 } 307 EXPORT_SYMBOL(drm_rect_rotate); 308 309 /** 310 * drm_rect_rotate_inv - Inverse rotate the rectangle 311 * @r: rectangle to be rotated 312 * @width: Width of the coordinate space 313 * @height: Height of the coordinate space 314 * @rotation: Transformation whose inverse is to be applied 315 * 316 * Apply the inverse of @rotation to the coordinates 317 * of rectangle @r. 318 * 319 * @width and @height combined with @rotation define 320 * the location of the new origin. 321 * 322 * @width correcsponds to the horizontal and @height 323 * to the vertical axis of the original untransformed 324 * coordinate space, so that you never have to flip 325 * them when doing a rotatation and its inverse. 326 * That is, if you do :: 327 * 328 * drm_rect_rotate(&r, width, height, rotation); 329 * drm_rect_rotate_inv(&r, width, height, rotation); 330 * 331 * you will always get back the original rectangle. 332 */ 333 void drm_rect_rotate_inv(struct drm_rect *r, 334 int width, int height, 335 unsigned int rotation) 336 { 337 struct drm_rect tmp; 338 339 switch (rotation & DRM_MODE_ROTATE_MASK) { 340 case DRM_MODE_ROTATE_0: 341 break; 342 case DRM_MODE_ROTATE_90: 343 tmp = *r; 344 r->x1 = width - tmp.y2; 345 r->x2 = width - tmp.y1; 346 r->y1 = tmp.x1; 347 r->y2 = tmp.x2; 348 break; 349 case DRM_MODE_ROTATE_180: 350 tmp = *r; 351 r->x1 = width - tmp.x2; 352 r->x2 = width - tmp.x1; 353 r->y1 = height - tmp.y2; 354 r->y2 = height - tmp.y1; 355 break; 356 case DRM_MODE_ROTATE_270: 357 tmp = *r; 358 r->x1 = tmp.y1; 359 r->x2 = tmp.y2; 360 r->y1 = height - tmp.x2; 361 r->y2 = height - tmp.x1; 362 break; 363 default: 364 break; 365 } 366 367 if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) { 368 tmp = *r; 369 370 if (rotation & DRM_MODE_REFLECT_X) { 371 r->x1 = width - tmp.x2; 372 r->x2 = width - tmp.x1; 373 } 374 375 if (rotation & DRM_MODE_REFLECT_Y) { 376 r->y1 = height - tmp.y2; 377 r->y2 = height - tmp.y1; 378 } 379 } 380 } 381 EXPORT_SYMBOL(drm_rect_rotate_inv); 382