drivers/gpu/drm/drm_rect.c

   1 /*
   2  * Copyright (C) 2011-2013 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  21  * SOFTWARE.
  22  */
  23
  24 #include <linux/errno.h>
  25 #include <linux/export.h>
  26 #include <linux/kernel.h>
  27
  28 #include <drm/drm_mode.h>
  29 #include <drm/drm_print.h>
  30 #include <drm/drm_rect.h>
  31
  32 /**
  33  * drm_rect_intersect - intersect two rectangles
  34  * @r1: first rectangle
  35  * @r2: second rectangle
  36  *
  37  * Calculate the intersection of rectangles @r1 and @r2.
  38  * @r1 will be overwritten with the intersection.
  39  *
  40  * RETURNS:
  41  * %true if rectangle @r1 is still visible after the operation,
  42  * %false otherwise.
  43  */
  44 bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
  45 {
  46         r1->x1 = max(r1->x1, r2->x1);
  47         r1->y1 = max(r1->y1, r2->y1);
  48         r1->x2 = min(r1->x2, r2->x2);
  49         r1->y2 = min(r1->y2, r2->y2);
  50
  51         return drm_rect_visible(r1);
  52 }
  53 EXPORT_SYMBOL(drm_rect_intersect);
  54
  55 static u32 clip_scaled(u32 src, u32 dst, u32 clip)
  56 {
  57         u64 tmp = mul_u32_u32(src, dst - clip);
  58
  59         /*
  60          * Round toward 1.0 when clipping so that we don't accidentally
  61          * change upscaling to downscaling or vice versa.
  62          */
  63         if (src < (dst << 16))
  64                 return DIV_ROUND_UP_ULL(tmp, dst);
  65         else
  66                 return DIV_ROUND_DOWN_ULL(tmp, dst);
  67 }
  68
  69 /**
  70  * drm_rect_clip_scaled - perform a scaled clip operation
  71  * @src: source window rectangle
  72  * @dst: destination window rectangle
  73  * @clip: clip rectangle
  74  *
  75  * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
  76  * same amounts multiplied by @hscale and @vscale.
  77  *
  78  * RETURNS:
  79  * %true if rectangle @dst is still visible after being clipped,
  80  * %false otherwise
  81  */
  82 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
  83                           const struct drm_rect *clip)
  84 {
  85         int diff;
  86
  87         diff = clip->x1 - dst->x1;
  88         if (diff > 0) {
  89                 u32 new_src_w = clip_scaled(drm_rect_width(src),
  90                                             drm_rect_width(dst), diff);
  91
  92                 src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX);
  93                 dst->x1 = clip->x1;
  94         }
  95         diff = clip->y1 - dst->y1;
  96         if (diff > 0) {
  97                 u32 new_src_h = clip_scaled(drm_rect_height(src),
  98                                             drm_rect_height(dst), diff);
  99
 100                 src->y1 = clamp_t(int64_t, src->y2 - new_src_h, INT_MIN, INT_MAX);
 101                 dst->y1 = clip->y1;
 102         }
 103         diff = dst->x2 - clip->x2;
 104         if (diff > 0) {
 105                 u32 new_src_w = clip_scaled(drm_rect_width(src),
 106                                             drm_rect_width(dst), diff);
 107
 108                 src->x2 = clamp_t(int64_t, src->x1 + new_src_w, INT_MIN, INT_MAX);
 109                 dst->x2 = clip->x2;
 110         }
 111         diff = dst->y2 - clip->y2;
 112         if (diff > 0) {
 113                 u32 new_src_h = clip_scaled(drm_rect_height(src),
 114                                             drm_rect_height(dst), diff);
 115
 116                 src->y2 = clamp_t(int64_t, src->y1 + new_src_h, INT_MIN, INT_MAX);
 117                 dst->y2 = clip->y2;
 118         }
 119
 120         return drm_rect_visible(dst);
 121 }
 122 EXPORT_SYMBOL(drm_rect_clip_scaled);
 123
 124 static int drm_calc_scale(int src, int dst)
 125 {
 126         int scale = 0;
 127
 128         if (WARN_ON(src < 0 || dst < 0))
 129                 return -EINVAL;
 130
 131         if (dst == 0)
 132                 return 0;
 133
 134         if (src > (dst << 16))
 135                 return DIV_ROUND_UP(src, dst);
 136         else
 137                 scale = src / dst;
 138
 139         return scale;
 140 }
 141
 142 /**
 143  * drm_rect_calc_hscale - calculate the horizontal scaling factor
 144  * @src: source window rectangle
 145  * @dst: destination window rectangle
 146  * @min_hscale: minimum allowed horizontal scaling factor
 147  * @max_hscale: maximum allowed horizontal scaling factor
 148  *
 149  * Calculate the horizontal scaling factor as
 150  * (@src width) / (@dst width).
 151  *
 152  * If the scale is below 1 << 16, round down. If the scale is above
 153  * 1 << 16, round up. This will calculate the scale with the most
 154  * pessimistic limit calculation.
 155  *
 156  * RETURNS:
 157  * The horizontal scaling factor, or errno of out of limits.
 158  */
 159 int drm_rect_calc_hscale(const struct drm_rect *src,
 160                          const struct drm_rect *dst,
 161                          int min_hscale, int max_hscale)
 162 {
 163         int src_w = drm_rect_width(src);
 164         int dst_w = drm_rect_width(dst);
 165         int hscale = drm_calc_scale(src_w, dst_w);
 166
 167         if (hscale < 0 || dst_w == 0)
 168                 return hscale;
 169
 170         if (hscale < min_hscale || hscale > max_hscale)
 171                 return -ERANGE;
 172
 173         return hscale;
 174 }
 175 EXPORT_SYMBOL(drm_rect_calc_hscale);
 176
 177 /**
 178  * drm_rect_calc_vscale - calculate the vertical scaling factor
 179  * @src: source window rectangle
 180  * @dst: destination window rectangle
 181  * @min_vscale: minimum allowed vertical scaling factor
 182  * @max_vscale: maximum allowed vertical scaling factor
 183  *
 184  * Calculate the vertical scaling factor as
 185  * (@src height) / (@dst height).
 186  *
 187  * If the scale is below 1 << 16, round down. If the scale is above
 188  * 1 << 16, round up. This will calculate the scale with the most
 189  * pessimistic limit calculation.
 190  *
 191  * RETURNS:
 192  * The vertical scaling factor, or errno of out of limits.
 193  */
 194 int drm_rect_calc_vscale(const struct drm_rect *src,
 195                          const struct drm_rect *dst,
 196                          int min_vscale, int max_vscale)
 197 {
 198         int src_h = drm_rect_height(src);
 199         int dst_h = drm_rect_height(dst);
 200         int vscale = drm_calc_scale(src_h, dst_h);
 201
 202         if (vscale < 0 || dst_h == 0)
 203                 return vscale;
 204
 205         if (vscale < min_vscale || vscale > max_vscale)
 206                 return -ERANGE;
 207
 208         return vscale;
 209 }
 210 EXPORT_SYMBOL(drm_rect_calc_vscale);
 211
 212 /**
 213  * drm_rect_debug_print - print the rectangle information
 214  * @prefix: prefix string
 215  * @r: rectangle to print
 216  * @fixed_point: rectangle is in 16.16 fixed point format
 217  */
 218 void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
 219 {
 220         if (fixed_point)
 221                 DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
 222         else
 223                 DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
 224 }
 225 EXPORT_SYMBOL(drm_rect_debug_print);
 226
 227 /**
 228  * drm_rect_rotate - Rotate the rectangle
 229  * @r: rectangle to be rotated
 230  * @width: Width of the coordinate space
 231  * @height: Height of the coordinate space
 232  * @rotation: Transformation to be applied
 233  *
 234  * Apply @rotation to the coordinates of rectangle @r.
 235  *
 236  * @width and @height combined with @rotation define
 237  * the location of the new origin.
 238  *
 239  * @width correcsponds to the horizontal and @height
 240  * to the vertical axis of the untransformed coordinate
 241  * space.
 242  */
 243 void drm_rect_rotate(struct drm_rect *r,
 244                      int width, int height,
 245                      unsigned int rotation)
 246 {
 247         struct drm_rect tmp;
 248
 249         if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
 250                 tmp = *r;
 251
 252                 if (rotation & DRM_MODE_REFLECT_X) {
 253                         r->x1 = width - tmp.x2;
 254                         r->x2 = width - tmp.x1;
 255                 }
 256
 257                 if (rotation & DRM_MODE_REFLECT_Y) {
 258                         r->y1 = height - tmp.y2;
 259                         r->y2 = height - tmp.y1;
 260                 }
 261         }
 262
 263         switch (rotation & DRM_MODE_ROTATE_MASK) {
 264         case DRM_MODE_ROTATE_0:
 265                 break;
 266         case DRM_MODE_ROTATE_90:
 267                 tmp = *r;
 268                 r->x1 = tmp.y1;
 269                 r->x2 = tmp.y2;
 270                 r->y1 = width - tmp.x2;
 271                 r->y2 = width - tmp.x1;
 272                 break;
 273         case DRM_MODE_ROTATE_180:
 274                 tmp = *r;
 275                 r->x1 = width - tmp.x2;
 276                 r->x2 = width - tmp.x1;
 277                 r->y1 = height - tmp.y2;
 278                 r->y2 = height - tmp.y1;
 279                 break;
 280         case DRM_MODE_ROTATE_270:
 281                 tmp = *r;
 282                 r->x1 = height - tmp.y2;
 283                 r->x2 = height - tmp.y1;
 284                 r->y1 = tmp.x1;
 285                 r->y2 = tmp.x2;
 286                 break;
 287         default:
 288                 break;
 289         }
 290 }
 291 EXPORT_SYMBOL(drm_rect_rotate);
 292
 293 /**
 294  * drm_rect_rotate_inv - Inverse rotate the rectangle
 295  * @r: rectangle to be rotated
 296  * @width: Width of the coordinate space
 297  * @height: Height of the coordinate space
 298  * @rotation: Transformation whose inverse is to be applied
 299  *
 300  * Apply the inverse of @rotation to the coordinates
 301  * of rectangle @r.
 302  *
 303  * @width and @height combined with @rotation define
 304  * the location of the new origin.
 305  *
 306  * @width correcsponds to the horizontal and @height
 307  * to the vertical axis of the original untransformed
 308  * coordinate space, so that you never have to flip
 309  * them when doing a rotatation and its inverse.
 310  * That is, if you do ::
 311  *
 312  *     drm_rect_rotate(&r, width, height, rotation);
 313  *     drm_rect_rotate_inv(&r, width, height, rotation);
 314  *
 315  * you will always get back the original rectangle.
 316  */
 317 void drm_rect_rotate_inv(struct drm_rect *r,
 318                          int width, int height,
 319                          unsigned int rotation)
 320 {
 321         struct drm_rect tmp;
 322
 323         switch (rotation & DRM_MODE_ROTATE_MASK) {
 324         case DRM_MODE_ROTATE_0:
 325                 break;
 326         case DRM_MODE_ROTATE_90:
 327                 tmp = *r;
 328                 r->x1 = width - tmp.y2;
 329                 r->x2 = width - tmp.y1;
 330                 r->y1 = tmp.x1;
 331                 r->y2 = tmp.x2;
 332                 break;
 333         case DRM_MODE_ROTATE_180:
 334                 tmp = *r;
 335                 r->x1 = width - tmp.x2;
 336                 r->x2 = width - tmp.x1;
 337                 r->y1 = height - tmp.y2;
 338                 r->y2 = height - tmp.y1;
 339                 break;
 340         case DRM_MODE_ROTATE_270:
 341                 tmp = *r;
 342                 r->x1 = tmp.y1;
 343                 r->x2 = tmp.y2;
 344                 r->y1 = height - tmp.x2;
 345                 r->y2 = height - tmp.x1;
 346                 break;
 347         default:
 348                 break;
 349         }
 350
 351         if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
 352                 tmp = *r;
 353
 354                 if (rotation & DRM_MODE_REFLECT_X) {
 355                         r->x1 = width - tmp.x2;
 356                         r->x2 = width - tmp.x1;
 357                 }
 358
 359                 if (rotation & DRM_MODE_REFLECT_Y) {
 360                         r->y1 = height - tmp.y2;
 361                         r->y2 = height - tmp.y1;
 362                 }
 363         }
 364 }
 365 EXPORT_SYMBOL(drm_rect_rotate_inv);