[AD] possible bug in draw_sprite_h_flip C version while clipping

["Cool Bool" <coolbool@xxxxxxxxxx>]

The sprite does not clip right,
I think sxbeg and w are not calculated right, I have included my unoptimized
fix. The code below shows what I mean.

with regards,
Deepak T(coolbool@xxxxxxxxxx)

#include <allegro.h>

// #define novideo
// Driver can be GFX_VGA, GFX_GDI, GFX_SAFE, GFX_AUTODETECT
// #define driver GFX_GDI
// #define driver GFX_VGA
 #define driver GFX_AUTODETECT

#define resw 640
#define resh 480
#define colordepth 16

#if colordepth==16
#include "d:\allegro\src\c\cdefs16.h"
#elif colordepth==15
#include "d:\allegro\src\c\cdefs15.h"
#elif colordepth==24
#include "d:\allegro\src\c\cdefs24.h"
#elif colordepth==32
#include "d:\allegro\src\c\cdefs32.h"
#endif

// #define nomouse
// #define nokeyboard

/* _linear_draw_sprite_h_flip:
 *  Draws a sprite to a linear bitmap, flipping horizontally.
 */
void draw_sprite_h_flipc(BITMAP *dst, BITMAP *src, int dx, int dy)
{
   int x, y, w, h;
   int dxbeg, dybeg;
   int sxbeg, sybeg;

   if (dst->clip) {
      int tmp;

 // possible bug here
      tmp = dst->cl - dx;
      sxbeg = ((tmp < 0) ? 0 : tmp);
      dxbeg = sxbeg + dx;

      tmp = dst->cr - dx;
      w = ((tmp > src->w) ? src->w : tmp) - sxbeg;
/*
 // fix
  sxbeg = 0;
  // crop from left
  if (dx <= 0) {
   dxbeg = 0;
   w = src->w + dx;
  }
  // inside the dst
  else {
   dxbeg = dx;
   w = src->w;
  }
  // crop from right
  tmp = dxbeg + w;
  if (tmp > dst->cr) {
   sxbeg = tmp - dst->cr;
   w = w - (tmp -dst->cr);
  }
*/
      if (w <= 0)
  return;

      dxbeg += w - 1;

      tmp = dst->ct - dy;
      sybeg = ((tmp < 0) ? 0 : tmp);
      dybeg = sybeg + dy;

      tmp = dst->cb - dy;
      h = ((tmp > src->h) ? src->h : tmp) - sybeg;
      if (h <= 0)
  return;
   }
   else {
      w = src->w;
      h = src->h;
      sxbeg = 0;
      sybeg = 0;
      dxbeg = dx + w - 1;
      dybeg = dy;
   }

   if (dst->id & (BMP_ID_VIDEO | BMP_ID_SYSTEM)) {
      bmp_select(dst);

      for (y = 0; y < h; y++) {
  PIXEL_PTR s = OFFSET_PIXEL_PTR(src->line[sybeg + y], sxbeg);
  PIXEL_PTR d = OFFSET_PIXEL_PTR(bmp_write_line(dst, dybeg + y), dxbeg);

  for (x = w - 1; x >= 0; INC_PIXEL_PTR(s), DEC_PIXEL_PTR(d), x--) {
     unsigned long c = GET_MEMORY_PIXEL(s);
     if (!IS_SPRITE_MASK(src, c)) {
        PUT_PIXEL(d, c);
     }
  }
      }

      bmp_unwrite_line(dst);
   }
   else {
      for (y = 0; y < h; y++) {
  PIXEL_PTR s = OFFSET_PIXEL_PTR(src->line[sybeg + y], sxbeg);
  PIXEL_PTR d = OFFSET_PIXEL_PTR(dst->line[dybeg + y], dxbeg);

  for (x = w - 1; x >= 0; INC_PIXEL_PTR(s), DEC_PIXEL_PTR(d), x--) {
     unsigned long c = GET_MEMORY_PIXEL(s);
     if (!IS_SPRITE_MASK(src, c)) {
        PUT_MEMORY_PIXEL(d, c);
     }
  }
      }
   }
}

int main()
{
  BITMAP *bmp, *buffer;

  allegro_init();

 #ifndef nokeyboard
  // set up the keyboard handler
 install_keyboard();
 #endif

 #ifndef nomouse
 // set up the mouse
 install_mouse();
 #endif

 #if driver==GFX_VGA
  #define resw 320
  #define resh 200
    #define colordepth 8
 #endif

 set_color_depth(colordepth);

 #ifndef novideo
  // set a graphics mode
  if (set_gfx_mode(driver, resw, resh, 0, 0) != 0) {
    set_gfx_mode(GFX_TEXT, 0, 0, 0, 0);
    allegro_message("Unable to set %dx%dx%d graphic mode\n%s\n",
   resw, resh, colordepth, allegro_error);
    return 1;
  }
 #endif

  // set the color palette
 #if colordepth<9
  set_palette(desktop_palette);
 #endif

 #ifndef novideo
  // clear the screen to white
  clear_to_color(screen, makecol(255, 255, 255));
 #endif

  // CODE
 bmp = load_bitmap("test.bmp", NULL);
 buffer = create_bitmap(resw, resh);
        if ((!bmp) || (!buffer)) return 1;
        clear(buffer);
        draw_sprite(buffer, bmp, 0, 0);
 draw_sprite_h_flipc(buffer, bmp, bmp->w/-2, bmp->h+10);
        blit(buffer, screen, 0, 0, 0, 0, buffer->w, buffer->h);
 readkey();
 destroy_bitmap(bmp);
 destroy_bitmap(buffer);
  return 0;
}
END_OF_MAIN();