X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=ld45_start_nothing;a=blobdiff_plain;f=src%2Fgfx.asm;fp=src%2Fgfx.asm;h=a3f2d39ea2efc34d2c2d8f328bad797a814bb3d9;hp=d35213935a64775454a4b5145621837a550a34a2;hb=6a16a1c526937ee551f968901cb949d55e35ecda;hpb=778d7ca8d282c31b4067f6a6e06df7be72822ea1

diff --git a/src/gfx.asm b/src/gfx.asm
index d352139..a3f2d39 100644
--- a/src/gfx.asm
+++ b/src/gfx.asm
@@ -28,8 +28,21 @@ init_gfx:
 	; video mode 13h (320x200 8bpp)
 	mov ax, 13h
 	int 10h
-
 	call clear
+
+	; setup the spritesheet palette
+	mov si, sprsheet_cmap
+	xor cl, cl
+.cmaploop:
+	mov al, cl
+	mov ah, [si]
+	mov bl, [si + 1]
+	mov bh, [si + 2]
+	add si, 3
+	call set_palette_entry
+	dec cl
+	jnz .cmaploop
+	
 	ret
 
 clear:
@@ -86,3 +99,51 @@ set_palette_entry:
 	out dx, al
 	pop dx
 	ret
+
+	; slow_sprite(short id, short x, short y)
+	; assumptions: 32x32, one after the other, 0 is transparent
+	; XXX sprsheet needs to go to its own segment
+slow_sprite:
+	push bp
+	mov bp, sp
+	pusha
+
+	mov ax, FRAMEBUF_SEG
+	mov es, ax
+	mov ax, [bp + 8]	; ax <- y
+	sub ax, 16		; ax <- y - 16 (center sprite vertically)
+	mov bx, ax
+	shl ax, 8
+	shl bx, 6
+	add ax, bx		; ax <- (y - 16) * 320
+	mov di, [bp + 6]	; di <- x
+	sub di, 16		; di <- x - 16 (center sprite horizontally)
+	add di, ax		; di <- (y - 16) * 320 + (x - 16)
+
+	mov si, sprsheet_tiles
+	; calculate sprite id offset (each spr is 32*32=1k)
+	mov ax, [bp + 4]
+	shl ax, 10
+	add si, ax
+
+	mov cx, 32
+.yloop:
+	xor bx, bx
+.xloop:
+	mov al, [si]
+	cmp al, 0
+	;jz .skip_pixel
+	mov [es:di + bx], al
+.skip_pixel:
+	inc si
+	inc bx
+	cmp bx, 32
+	jnz .xloop
+
+	add di, 320
+	dec cx
+	jnz .yloop
+
+	popa
+	pop bp
+	ret