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);