SDL-1.2: Implement X mirroring for quads

src/gfx/sdl-1.2/inc/gfx/port.h

@@ -11,7 +11,7 @@ extern "C"
 
 struct sprite
 {
-    SDL_Surface *s;
+    SDL_Surface *s, *s_x;
     short x, y, w, h;
     unsigned char u, v;
     bool transparent;
@@ -24,8 +24,9 @@ struct quad
     short y0, y1, y2, y3;
     unsigned char u0, u1, u2, u3;
     unsigned char v0, v1, v2, v3;
+    short w, h;
     bool transparent;
-    SDL_Surface *s;
+    SDL_Surface *s, *s_x;
 };
 
 struct rect

src/gfx/sdl-1.2/src/quad.c

@@ -7,29 +7,38 @@
 int quad_from_sprite(const struct sprite *const s, struct quad *const q)
 {
     q->s = s->s;
+    q->s_x = s->s_x;
     q->u0 = q->u2 = s->u;
     q->v0 = q->v1 = s->v;
     q->u1 = q->u3 = s->u + s->w - 1;
     q->v2 = q->v3 = s->v + s->h - 1;
+    q->w = s->w;
+    q->h = s->h;
     return 0;
 }
 
 void quad_sort(struct quad *const q)
 {
+    const bool xflip = q->x0 > q->x1;
+
     SDL_Rect r =
     {
-        .x = q->x0,
+        .x = xflip ? q->x1 : q->x0,
         .y = q->y0
     };
 
+    const short w = q->u1 - q->u0 + 1, h = q->v2 - q->v0 + 1;
+
     SDL_Rect clip =
     {
-        .x = q->u0,
+        .x = xflip ? q->w - q->u0 - w: q->u0,
         .y = q->v0,
-        .w = q->u1 - q->u0 + 1,
+        .w = w,
-        .h= q->v2 - q->v0 + 1
+        .h = h
     };
 
-    if (SDL_BlitSurface(q->s, &clip, gfx_screen(), &r))
+    SDL_Surface *const s = xflip ? q->s_x : q->s;
+
+    if (SDL_BlitSurface(s, &clip, gfx_screen(), &r))
         fprintf(stderr, "SDL_BlitSurface: %s\n", SDL_GetError());
 }

src/gfx/sdl-1.2/src/sprite.c

@@ -3,6 +3,7 @@
 #include <header.h>
 #include <sdl-1.2/gfx_private.h>
 #include <SDL/SDL.h>
+#include <SDL/SDL_rotozoom.h>
 #include <errno.h>
 #include <stddef.h>
 #include <stdlib.h>
@@ -19,20 +20,32 @@ int sprite_clone(const struct sprite *const src, struct sprite *const dst)
     return 0;
 }
 
+static int set_transparent(SDL_Surface *const s)
+{
+    /* Magenta as transparent. */
+    const Uint32 map = SDL_MapRGB(s->format, 255, 0, 255);
+    const int ret = SDL_SetColorKey(s, SDL_SRCCOLORKEY | SDL_RLEACCEL, map);
+
+    if (ret)
+        fprintf(stderr, "SDL_SetColorKey: %s\n", SDL_GetError());
+
+    return ret;
+}
+
 int sprite_screen_resize_ev(struct sprite *const s)
 {
     int ret = -1;
-    SDL_Surface *const old = s->s;
+    SDL_Surface *const old = s->s, *const old_x = s->s_x;
 
     /* Magenta as transparent. */
-    if (s->transparent
+    if (s->transparent && (set_transparent(old) || set_transparent(old_x)))
-        && SDL_SetColorKey(old, SDL_SRCCOLORKEY | SDL_RLEACCEL,
+        goto end;
-            SDL_MapRGB(old->format, 255, 0, 255)))
+    else if (!(s->s = SDL_DisplayFormat(old)))
     {
-        fprintf(stderr, "SDL_SetColorKey: %s\n", SDL_GetError());
+        fprintf(stderr, "SDL_DisplayFormat: %s\n", SDL_GetError());
         goto end;
     }
-    else if (!(s->s = SDL_DisplayFormat(old)))
+    else if (!(s->s_x = SDL_DisplayFormat(old_x)))
     {
         fprintf(stderr, "SDL_DisplayFormat: %s\n", SDL_GetError());
         goto end;
@@ -42,6 +55,7 @@ int sprite_screen_resize_ev(struct sprite *const s)
 
 end:
     SDL_FreeSurface(old);
+    SDL_FreeSurface(old_x);
     return ret;
 }
 
@@ -57,31 +71,35 @@ static int load_bitmap(struct sprite *const s, FILE *const f)
 {
     int ret = -1;
     SDL_RWops *ops = NULL;
-    SDL_Surface *ts = NULL;
+    SDL_Surface *ts = NULL, *zs = NULL;
 
     if (!(ops = SDL_RWFromFP(f, 0)))
     {
         fprintf(stderr, "SDL_RWFromFP: %s\n", SDL_GetError());
         goto end;
     }
-    if (!(ts = SDL_LoadBMP_RW(ops, 0)))
+    else if (!(ts = SDL_LoadBMP_RW(ops, 0)))
     {
         fprintf(stderr, "SDL_LoadBMP_RW: %s\n", SDL_GetError());
         goto end;
     }
-    /* Magenta as transparent. */
+    else if (!(zs = zoomSurface(ts, -1, 1, 0)))
-    else if (s->transparent
-        && SDL_SetColorKey(ts, SDL_SRCCOLORKEY | SDL_RLEACCEL,
-            SDL_MapRGB(ts->format, 255, 0, 255)))
     {
-        fprintf(stderr, "SDL_SetColorKey: %s\n", SDL_GetError());
+        fprintf(stderr, "zoomSurface: %s\n", SDL_GetError());
         goto end;
     }
+    else if (s->transparent && (set_transparent(ts) || set_transparent(zs)))
+        goto end;
     else if (!(s->s = SDL_DisplayFormat(ts)))
     {
         fprintf(stderr, "SDL_DisplayFormat: %s\n", SDL_GetError());
         goto end;
     }
+    else if (!(s->s_x = SDL_DisplayFormat(zs)))
+    {
+        fprintf(stderr, "SDL_DisplayFormat: %s\n", SDL_GetError());
+        goto end;
+    }
 
     gfx_register_sprite(s);
     s->w = ts->w;