git.gag.com Git - fw/altos/blob - src/draw/ao_copy.c

   1 /*
   2  * Copyright © 2016 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  */
  14
  15 #include "ao.h"
  16 #include "ao_draw.h"
  17 #include "ao_draw_int.h"
  18
  19 #define bound(val,max,other) do {               \
  20                 if (val < 0) {                  \
  21                         other -= val;           \
  22                         val = 0;                \
  23                 }                               \
  24                 if (val > max) {                \
  25                         other -= (val - max);   \
  26                         val = max;              \
  27                 }                               \
  28         } while (0)
  29
  30 #define bound2(a, max_a, b, max_b) do {         \
  31                 bound(a, max_a, b);             \
  32                 bound(b, max_b, a);             \
  33         } while (0)
  34
  35 void
  36 ao_copy(const struct ao_bitmap  *dst,
  37         int16_t                 dst_x,
  38         int16_t                 dst_y,
  39         int16_t                 width,
  40         int16_t                 height,
  41         const struct ao_bitmap  *src,
  42         int16_t                 src_x,
  43         int16_t                 src_y,
  44         uint8_t                 rop)
  45 {
  46         int16_t         dst_x2 = dst_x + width, dst_y2 = dst_y + height;
  47         int16_t         src_x2 = src_x + width, src_y2 = src_y + height;
  48         uint8_t         reverse = 0;
  49         uint8_t         upsidedown = 0;
  50
  51         bound2(dst_x, dst->width, src_x, src->width);
  52         bound2(dst_x2, dst->width, src_x2, src->width);
  53         bound2(dst_y, dst->height, src_y, src->height);
  54         bound2(dst_y2, dst->height, src_y2, src->height);
  55
  56         if (dst == src) {
  57                 reverse = (dst_x > src_x);
  58                 upsidedown = (dst_y > src_y);
  59         }
  60
  61         if (dst_x < dst_x2 && dst_y < dst_y2) {
  62                 ao_blt(src->base + src_y * src->stride,
  63                        src->stride,
  64                        src_x,
  65                        dst->base + dst_y * dst->stride,
  66                        dst->stride,
  67                        dst_x,
  68                        dst_x2 - dst_x,
  69                        dst_y2 - dst_y,
  70                        rop,
  71                        reverse,
  72                        upsidedown);
  73         }
  74 }
  75