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 #include <drm/drm_rect.h>
  28
  29 /**
  30  * drm_rect_intersect - intersect two rectangles
  31  * @r1: first rectangle
  32  * @r2: second rectangle
  33  *
  34  * Calculate the intersection of rectangles @r1 and @r2.
  35  * @r1 will be overwritten with the intersection.
  36  *
  37  * RETURNS:
  38  * %true if rectangle @r1 is still visible after the operation,
  39  * %false otherwise.
  40  */
  41 bool drm_rect_intersect(struct drm_rect *r1, const struct drm_rect *r2)
  42 {
  43         r1->x1 = max(r1->x1, r2->x1);
  44         r1->y1 = max(r1->y1, r2->y1);
  45         r1->x2 = min(r1->x2, r2->x2);
  46         r1->y2 = min(r1->y2, r2->y2);
  47
  48         return drm_rect_visible(r1);
  49 }
  50 EXPORT_SYMBOL(drm_rect_intersect);
  51
  52 /**
  53  * drm_rect_clip_scaled - perform a scaled clip operation
  54  * @src: source window rectangle
  55  * @dst: destination window rectangle
  56  * @clip: clip rectangle
  57  * @hscale: horizontal scaling factor
  58  * @vscale: vertical scaling factor
  59  *
  60  * Clip rectangle @dst by rectangle @clip. Clip rectangle @src by the
  61  * same amounts multiplied by @hscale and @vscale.
  62  *
  63  * RETURNS:
  64  * %true if rectangle @dst is still visible after being clipped,
  65  * %false otherwise
  66  */
  67 bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst,
  68                           const struct drm_rect *clip,
  69                           int hscale, int vscale)
  70 {
  71         int diff;
  72
  73         diff = clip->x1 - dst->x1;
  74         if (diff > 0) {
  75                 int64_t tmp = src->x1 + (int64_t) diff * hscale;
  76                 src->x1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
  77         }
  78         diff = clip->y1 - dst->y1;
  79         if (diff > 0) {
  80                 int64_t tmp = src->y1 + (int64_t) diff * vscale;
  81                 src->y1 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
  82         }
  83         diff = dst->x2 - clip->x2;
  84         if (diff > 0) {
  85                 int64_t tmp = src->x2 - (int64_t) diff * hscale;
  86                 src->x2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
  87         }
  88         diff = dst->y2 - clip->y2;
  89         if (diff > 0) {
  90                 int64_t tmp = src->y2 - (int64_t) diff * vscale;
  91                 src->y2 = clamp_t(int64_t, tmp, INT_MIN, INT_MAX);
  92         }
  93
  94         return drm_rect_intersect(dst, clip);
  95 }
  96 EXPORT_SYMBOL(drm_rect_clip_scaled);
  97
  98 static int drm_calc_scale(int src, int dst)
  99 {
 100         int scale = 0;
 101
 102         if (src < 0 || dst < 0)
 103                 return -EINVAL;
 104
 105         if (dst == 0)
 106                 return 0;
 107
 108         scale = src / dst;
 109
 110         return scale;
 111 }
 112
 113 /**
 114  * drm_rect_calc_hscale - calculate the horizontal scaling factor
 115  * @src: source window rectangle
 116  * @dst: destination window rectangle
 117  * @min_hscale: minimum allowed horizontal scaling factor
 118  * @max_hscale: maximum allowed horizontal scaling factor
 119  *
 120  * Calculate the horizontal scaling factor as
 121  * (@src width) / (@dst width).
 122  *
 123  * RETURNS:
 124  * The horizontal scaling factor, or errno of out of limits.
 125  */
 126 int drm_rect_calc_hscale(const struct drm_rect *src,
 127                          const struct drm_rect *dst,
 128                          int min_hscale, int max_hscale)
 129 {
 130         int src_w = drm_rect_width(src);
 131         int dst_w = drm_rect_width(dst);
 132         int hscale = drm_calc_scale(src_w, dst_w);
 133
 134         if (hscale < 0 || dst_w == 0)
 135                 return hscale;
 136
 137         if (hscale < min_hscale || hscale > max_hscale)
 138                 return -ERANGE;
 139
 140         return hscale;
 141 }
 142 EXPORT_SYMBOL(drm_rect_calc_hscale);
 143
 144 /**
 145  * drm_rect_calc_vscale - calculate the vertical scaling factor
 146  * @src: source window rectangle
 147  * @dst: destination window rectangle
 148  * @min_vscale: minimum allowed vertical scaling factor
 149  * @max_vscale: maximum allowed vertical scaling factor
 150  *
 151  * Calculate the vertical scaling factor as
 152  * (@src height) / (@dst height).
 153  *
 154  * RETURNS:
 155  * The vertical scaling factor, or errno of out of limits.
 156  */
 157 int drm_rect_calc_vscale(const struct drm_rect *src,
 158                          const struct drm_rect *dst,
 159                          int min_vscale, int max_vscale)
 160 {
 161         int src_h = drm_rect_height(src);
 162         int dst_h = drm_rect_height(dst);
 163         int vscale = drm_calc_scale(src_h, dst_h);
 164
 165         if (vscale < 0 || dst_h == 0)
 166                 return vscale;
 167
 168         if (vscale < min_vscale || vscale > max_vscale)
 169                 return -ERANGE;
 170
 171         return vscale;
 172 }
 173 EXPORT_SYMBOL(drm_rect_calc_vscale);
 174
 175 /**
 176  * drm_calc_hscale_relaxed - calculate the horizontal scaling factor
 177  * @src: source window rectangle
 178  * @dst: destination window rectangle
 179  * @min_hscale: minimum allowed horizontal scaling factor
 180  * @max_hscale: maximum allowed horizontal scaling factor
 181  *
 182  * Calculate the horizontal scaling factor as
 183  * (@src width) / (@dst width).
 184  *
 185  * If the calculated scaling factor is below @min_vscale,
 186  * decrease the height of rectangle @dst to compensate.
 187  *
 188  * If the calculated scaling factor is above @max_vscale,
 189  * decrease the height of rectangle @src to compensate.
 190  *
 191  * RETURNS:
 192  * The horizontal scaling factor.
 193  */
 194 int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
 195                                  struct drm_rect *dst,
 196                                  int min_hscale, int max_hscale)
 197 {
 198         int src_w = drm_rect_width(src);
 199         int dst_w = drm_rect_width(dst);
 200         int hscale = drm_calc_scale(src_w, dst_w);
 201
 202         if (hscale < 0 || dst_w == 0)
 203                 return hscale;
 204
 205         if (hscale < min_hscale) {
 206                 int max_dst_w = src_w / min_hscale;
 207
 208                 drm_rect_adjust_size(dst, max_dst_w - dst_w, 0);
 209
 210                 return min_hscale;
 211         }
 212
 213         if (hscale > max_hscale) {
 214                 int max_src_w = dst_w * max_hscale;
 215
 216                 drm_rect_adjust_size(src, max_src_w - src_w, 0);
 217
 218                 return max_hscale;
 219         }
 220
 221         return hscale;
 222 }
 223 EXPORT_SYMBOL(drm_rect_calc_hscale_relaxed);
 224
 225 /**
 226  * drm_rect_calc_vscale_relaxed - calculate the vertical scaling factor
 227  * @src: source window rectangle
 228  * @dst: destination window rectangle
 229  * @min_vscale: minimum allowed vertical scaling factor
 230  * @max_vscale: maximum allowed vertical scaling factor
 231  *
 232  * Calculate the vertical scaling factor as
 233  * (@src height) / (@dst height).
 234  *
 235  * If the calculated scaling factor is below @min_vscale,
 236  * decrease the height of rectangle @dst to compensate.
 237  *
 238  * If the calculated scaling factor is above @max_vscale,
 239  * decrease the height of rectangle @src to compensate.
 240  *
 241  * RETURNS:
 242  * The vertical scaling factor.
 243  */
 244 int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
 245                                  struct drm_rect *dst,
 246                                  int min_vscale, int max_vscale)
 247 {
 248         int src_h = drm_rect_height(src);
 249         int dst_h = drm_rect_height(dst);
 250         int vscale = drm_calc_scale(src_h, dst_h);
 251
 252         if (vscale < 0 || dst_h == 0)
 253                 return vscale;
 254
 255         if (vscale < min_vscale) {
 256                 int max_dst_h = src_h / min_vscale;
 257
 258                 drm_rect_adjust_size(dst, 0, max_dst_h - dst_h);
 259
 260                 return min_vscale;
 261         }
 262
 263         if (vscale > max_vscale) {
 264                 int max_src_h = dst_h * max_vscale;
 265
 266                 drm_rect_adjust_size(src, 0, max_src_h - src_h);
 267
 268                 return max_vscale;
 269         }
 270
 271         return vscale;
 272 }
 273 EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);