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(int src, int dst, int *clip)
  56 {
  57         u64 tmp;
  58
  59         if (dst == 0)
  60                 return 0;
  61
  62         /* Only clip what we have. Keeps the result bounded. */
  63         *clip = min(*clip, dst);
  64
  65         tmp = mul_u32_u32(src, dst - *clip);
  66
  67         /*
  68          * Round toward 1.0 when clipping so that we don't accidentally
  69          * change upscaling to downscaling or vice versa.
  70          */
  71         if (src < (dst << 16))
  72                 return DIV_ROUND_UP_ULL(tmp, dst);
  73         else
  74                 return DIV_ROUND_DOWN_ULL(tmp, dst);
  75 }
  76
  77 /**
  78  * drm_rect_clip_scaled - perform a scaled clip operation
  79  * @src: source window rectangle
  80  * @dst: destination window rectangle
  81  * @clip: clip rectangle
  82  *
  83  * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
  84  * the corresponding amounts, retaining the vertical and horizontal scaling
  85  * factors from @src to @dst.
  86  *
  87  * RETURNS:
  88  *
  89  * %true if rectangle @dst is still visible after being clipped,
  90  * %false otherwise.
  91  */
  92 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
  93                           const struct drm_rect *clip)
  94 {
  95         int diff;
  96
  97         diff = clip->x1 - dst->x1;
  98         if (diff > 0) {
  99                 u32 new_src_w = clip_scaled(drm_rect_width(src),
 100                                             drm_rect_width(dst), &diff);
 101
 102                 src->x1 = src->x2 - new_src_w;
 103                 dst->x1 += diff;
 104         }
 105         diff = clip->y1 - dst->y1;
 106         if (diff > 0) {
 107                 u32 new_src_h = clip_scaled(drm_rect_height(src),
 108                                             drm_rect_height(dst), &diff);
 109
 110                 src->y1 = src->y2 - new_src_h;
 111                 dst->y1 += diff;
 112         }
 113         diff = dst->x2 - clip->x2;
 114         if (diff > 0) {
 115                 u32 new_src_w = clip_scaled(drm_rect_width(src),
 116                                             drm_rect_width(dst), &diff);
 117
 118                 src->x2 = src->x1 + new_src_w;
 119                 dst->x2 -= diff;
 120         }
 121         diff = dst->y2 - clip->y2;
 122         if (diff > 0) {
 123                 u32 new_src_h = clip_scaled(drm_rect_height(src),
 124                                             drm_rect_height(dst), &diff);
 125
 126                 src->y2 = src->y1 + new_src_h;
 127                 dst->y2 -= diff;
 128         }
 129
 130         return drm_rect_visible(dst);
 131 }
 132 EXPORT_SYMBOL(drm_rect_clip_scaled);
 133
 134 static int drm_calc_scale(int src, int dst)
 135 {
 136         int scale = 0;
 137
 138         if (WARN_ON(src < 0 || dst < 0))
 139                 return -EINVAL;
 140
 141         if (dst == 0)
 142                 return 0;
 143
 144         if (src > (dst << 16))
 145                 return DIV_ROUND_UP(src, dst);
 146         else
 147                 scale = src / dst;
 148
 149         return scale;
 150 }
 151
 152 /**
 153  * drm_rect_calc_hscale - calculate the horizontal scaling factor
 154  * @src: source window rectangle
 155  * @dst: destination window rectangle
 156  * @min_hscale: minimum allowed horizontal scaling factor
 157  * @max_hscale: maximum allowed horizontal scaling factor
 158  *
 159  * Calculate the horizontal scaling factor as
 160  * (@src width) / (@dst width).
 161  *
 162  * If the scale is below 1 << 16, round down. If the scale is above
 163  * 1 << 16, round up. This will calculate the scale with the most
 164  * pessimistic limit calculation.
 165  *
 166  * RETURNS:
 167  * The horizontal scaling factor, or errno of out of limits.
 168  */
 169 int drm_rect_calc_hscale(const struct drm_rect *src,
 170                          const struct drm_rect *dst,
 171                          int min_hscale, int max_hscale)
 172 {
 173         int src_w = drm_rect_width(src);
 174         int dst_w = drm_rect_width(dst);
 175         int hscale = drm_calc_scale(src_w, dst_w);
 176
 177         if (hscale < 0 || dst_w == 0)
 178                 return hscale;
 179
 180         if (hscale < min_hscale || hscale > max_hscale)
 181                 return -ERANGE;
 182
 183         return hscale;
 184 }
 185 EXPORT_SYMBOL(drm_rect_calc_hscale);
 186
 187 /**
 188  * drm_rect_calc_vscale - calculate the vertical scaling factor
 189  * @src: source window rectangle
 190  * @dst: destination window rectangle
 191  * @min_vscale: minimum allowed vertical scaling factor
 192  * @max_vscale: maximum allowed vertical scaling factor
 193  *
 194  * Calculate the vertical scaling factor as
 195  * (@src height) / (@dst height).
 196  *
 197  * If the scale is below 1 << 16, round down. If the scale is above
 198  * 1 << 16, round up. This will calculate the scale with the most
 199  * pessimistic limit calculation.
 200  *
 201  * RETURNS:
 202  * The vertical scaling factor, or errno of out of limits.
 203  */
 204 int drm_rect_calc_vscale(const struct drm_rect *src,
 205                          const struct drm_rect *dst,
 206                          int min_vscale, int max_vscale)
 207 {
 208         int src_h = drm_rect_height(src);
 209         int dst_h = drm_rect_height(dst);
 210         int vscale = drm_calc_scale(src_h, dst_h);
 211
 212         if (vscale < 0 || dst_h == 0)
 213                 return vscale;
 214
 215         if (vscale < min_vscale || vscale > max_vscale)
 216                 return -ERANGE;
 217
 218         return vscale;
 219 }
 220 EXPORT_SYMBOL(drm_rect_calc_vscale);
 221
 222 /**
 223  * drm_rect_debug_print - print the rectangle information
 224  * @prefix: prefix string
 225  * @r: rectangle to print
 226  * @fixed_point: rectangle is in 16.16 fixed point format
 227  */
 228 void drm_rect_debug_print(const char *prefix, const struct drm_rect *r, bool fixed_point)
 229 {
 230         if (fixed_point)
 231                 DRM_DEBUG_KMS("%s" DRM_RECT_FP_FMT "\n", prefix, DRM_RECT_FP_ARG(r));
 232         else
 233                 DRM_DEBUG_KMS("%s" DRM_RECT_FMT "\n", prefix, DRM_RECT_ARG(r));
 234 }
 235 EXPORT_SYMBOL(drm_rect_debug_print);
 236
 237 /**
 238  * drm_rect_rotate - Rotate the rectangle
 239  * @r: rectangle to be rotated
 240  * @width: Width of the coordinate space
 241  * @height: Height of the coordinate space
 242  * @rotation: Transformation to be applied
 243  *
 244  * Apply @rotation to the coordinates of rectangle @r.
 245  *
 246  * @width and @height combined with @rotation define
 247  * the location of the new origin.
 248  *
 249  * @width correcsponds to the horizontal and @height
 250  * to the vertical axis of the untransformed coordinate
 251  * space.
 252  */
 253 void drm_rect_rotate(struct drm_rect *r,
 254                      int width, int height,
 255                      unsigned int rotation)
 256 {
 257         struct drm_rect tmp;
 258
 259         if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
 260                 tmp = *r;
 261
 262                 if (rotation & DRM_MODE_REFLECT_X) {
 263                         r->x1 = width - tmp.x2;
 264                         r->x2 = width - tmp.x1;
 265                 }
 266
 267                 if (rotation & DRM_MODE_REFLECT_Y) {
 268                         r->y1 = height - tmp.y2;
 269                         r->y2 = height - tmp.y1;
 270                 }
 271         }
 272
 273         switch (rotation & DRM_MODE_ROTATE_MASK) {
 274         case DRM_MODE_ROTATE_0:
 275                 break;
 276         case DRM_MODE_ROTATE_90:
 277                 tmp = *r;
 278                 r->x1 = tmp.y1;
 279                 r->x2 = tmp.y2;
 280                 r->y1 = width - tmp.x2;
 281                 r->y2 = width - tmp.x1;
 282                 break;
 283         case DRM_MODE_ROTATE_180:
 284                 tmp = *r;
 285                 r->x1 = width - tmp.x2;
 286                 r->x2 = width - tmp.x1;
 287                 r->y1 = height - tmp.y2;
 288                 r->y2 = height - tmp.y1;
 289                 break;
 290         case DRM_MODE_ROTATE_270:
 291                 tmp = *r;
 292                 r->x1 = height - tmp.y2;
 293                 r->x2 = height - tmp.y1;
 294                 r->y1 = tmp.x1;
 295                 r->y2 = tmp.x2;
 296                 break;
 297         default:
 298                 break;
 299         }
 300 }
 301 EXPORT_SYMBOL(drm_rect_rotate);
 302
 303 /**
 304  * drm_rect_rotate_inv - Inverse rotate the rectangle
 305  * @r: rectangle to be rotated
 306  * @width: Width of the coordinate space
 307  * @height: Height of the coordinate space
 308  * @rotation: Transformation whose inverse is to be applied
 309  *
 310  * Apply the inverse of @rotation to the coordinates
 311  * of rectangle @r.
 312  *
 313  * @width and @height combined with @rotation define
 314  * the location of the new origin.
 315  *
 316  * @width correcsponds to the horizontal and @height
 317  * to the vertical axis of the original untransformed
 318  * coordinate space, so that you never have to flip
 319  * them when doing a rotatation and its inverse.
 320  * That is, if you do ::
 321  *
 322  *     drm_rect_rotate(&r, width, height, rotation);
 323  *     drm_rect_rotate_inv(&r, width, height, rotation);
 324  *
 325  * you will always get back the original rectangle.
 326  */
 327 void drm_rect_rotate_inv(struct drm_rect *r,
 328                          int width, int height,
 329                          unsigned int rotation)
 330 {
 331         struct drm_rect tmp;
 332
 333         switch (rotation & DRM_MODE_ROTATE_MASK) {
 334         case DRM_MODE_ROTATE_0:
 335                 break;
 336         case DRM_MODE_ROTATE_90:
 337                 tmp = *r;
 338                 r->x1 = width - tmp.y2;
 339                 r->x2 = width - tmp.y1;
 340                 r->y1 = tmp.x1;
 341                 r->y2 = tmp.x2;
 342                 break;
 343         case DRM_MODE_ROTATE_180:
 344                 tmp = *r;
 345                 r->x1 = width - tmp.x2;
 346                 r->x2 = width - tmp.x1;
 347                 r->y1 = height - tmp.y2;
 348                 r->y2 = height - tmp.y1;
 349                 break;
 350         case DRM_MODE_ROTATE_270:
 351                 tmp = *r;
 352                 r->x1 = tmp.y1;
 353                 r->x2 = tmp.y2;
 354                 r->y1 = height - tmp.x2;
 355                 r->y2 = height - tmp.x1;
 356                 break;
 357         default:
 358                 break;
 359         }
 360
 361         if (rotation & (DRM_MODE_REFLECT_X | DRM_MODE_REFLECT_Y)) {
 362                 tmp = *r;
 363
 364                 if (rotation & DRM_MODE_REFLECT_X) {
 365                         r->x1 = width - tmp.x2;
 366                         r->x2 = width - tmp.x1;
 367                 }
 368
 369                 if (rotation & DRM_MODE_REFLECT_Y) {
 370                         r->y1 = height - tmp.y2;
 371                         r->y2 = height - tmp.y1;
 372                 }
 373         }
 374 }
 375 EXPORT_SYMBOL(drm_rect_rotate_inv);