From 290fe3c6727ce61652276d0e01357d25ea050366 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Tue, 31 Jul 2018 20:15:18 +0300
Subject: [PATCH] sprites in progress

---
 src/sprite.c |   67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/sprite.h |   13 +++++++-----
 2 files changed, 75 insertions(+), 5 deletions(-)
 create mode 100644 src/sprite.c

diff --git a/src/sprite.c b/src/sprite.c
new file mode 100644
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
--- 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_ */
-- 
1.7.10.4