sprites in progress

diff --git a/src/sprite.c b/src/sprite.c
new file mode 100644 (file)
index 0000000..3a00881
--- /dev/null
+++ b/src/sprite.c
@@ -0,0 +1,67 @@
+#include <string.h>
+#include "sprite.h"
+
+#define MAX_SPRITES    32
+
+static int scount;
+static sprite *spr[MAX_SPRITES];
+static sprite *hwspr[4];       /* 4 channels because we support only attached sprites */
+
+void begin_sprites(void)
+{
+       scount = 0;
+       memset(hwspr_used, 0, sizeof hwspr_used);
+}
+
+void end_sprites(void)
+{
+       int i, j;
+
+       /* sort sprites by increasing start position */
+       for(i=0; i<scount; i++) {
+               for(j=i+1; j<scount; j++) {
+                       if(spr[j]->y < spr[i]->y) {
+                               struct sprite *tmp = spr[i];
+                               spr[i] = spr[j];
+                               spr[j] = tmp;
+                       }
+               }
+       }
+
+       /* set sprite positions and populate copperlist to draw
+        * hardware sprites
+        */
+       for(i=0; i<scount; i++) {
+               struct sprite *s = spr[i];
+               uint16_t sx = 0x80 + s->x;
+               uint16_t sy = 0x2c + s->y;
+               uint16_t vstop = sy + s->height;
+
+               int chan = -1;
+               for(j=0; j<4; j++) {
+                       if(!hwspr[j] || hwspr[j]->y + hwspr[j]->height < s->y) {
+                               chan = j;
+                               hwspr[j] = s;
+                       }
+               }
+               if(chan == -1) continue;
+
+               for(j=0; j<s->hwslices; j++) {
+                       s->hwspr[idx][0] = s->hwspr[idx + 1][0] = (sx >> 1) | (sy << 8);
+                       s->hwspr[idx][1] = s->hwspr[idx + 1][1] = (vstop << 8) |
+                               ((vstop >> 7) & 2) | (sx & 1) | 0x80;
+               }
+       }
+}
+
+void draw_sprite(struct sprite *s, int x, int y)
+{
+       if(s->img) {
+               /* blitter sprite */
+       } else {
+               /* hw sprites */
+               spr[scount++] = s;
+               s->x = x - origx;
+               s->y = y - origy;
+       }
+}

diff --git a/src/sprite.h b/src/sprite.h
index bd85467..0428ed0 100644 (file)
--- a/src/sprite.h
+++ b/src/sprite.h
@@ -1,20 +1,23 @@
 #ifndef SPRITE_H_
 #define SPRITE_H_
 
+#include <stdint.h>
+
 struct sprite {
-       int width, height;
-       int origx, origy;
+       int16_t x, y;
+       uint16_t width, height;
+       int16_t origx, origy;
 
        /* img/mask used for blitter sprites */
        void *img, *mask;
 
        /* hardware sprite data */
-       int hwslices;
        uint16_t *hwspr[8];
+       uint8_t hwslices;
 };
 
-void begin_sprites();
-void end_sprites();
+void begin_sprites(void);
+void end_sprites(void);
 void draw_sprite(struct sprite *s, int x, int y);
 
 #endif /* SPRITE_H_ */