mirror of https://github.com/nmlgc/ReC98.git
52 lines
1.1 KiB
NASM
52 lines
1.1 KiB
NASM
|
; Draws the hardcoded spark sprite with the given ID, with ([x], [vram_y])
|
||
|
|
; pointing to the top-left point. Assumptions:
|
||
|
|
; • The GRCG is active, and set to the intended color
|
||
|
|
; • [sprite_id] ≤ SPARK_SPRITES
|
||
|
|
|
||
|
|
; void pascal near spark_render(int x, int vram_y, int sprite_id);
|
||
|
|
spark_render proc near
|
||
|
|
@@sprite_id = word ptr 4
|
||
|
|
@@vram_y = word ptr 6
|
||
|
|
@@x = word ptr 8
|
||
|
|
|
||
|
|
push bp
|
||
|
|
mov bp, sp
|
||
|
|
push si
|
||
|
|
push di
|
||
|
|
mov ax, GRAM_400
|
||
|
|
mov es, ax
|
||
|
|
mov bx, [bp+@@x]
|
||
|
|
mov ax, bx
|
||
|
|
sar ax, 3 ; x /= 8
|
||
|
|
mov dx, [bp+@@vram_y]
|
||
|
|
shl dx, 6 ; [vram_y] * 64
|
||
|
|
add ax, dx
|
||
|
|
shr dx, 2 ; (([vram_y] * 64) / 4) = [vram_y] * 16
|
||
|
|
add ax, dx
|
||
|
|
mov di, ax ; ([vram_y] * 64) + ([vram_y] * 16) = [vram_y * ROW_SIZE]
|
||
|
|
mov ax, bx
|
||
|
|
and ax, 7 ; [x] & 7
|
||
|
|
shl ax, 7 ; *= SPARK_SIZE * SPARK_SPRITES (offset of X-shifted sprite)
|
||
|
|
mov dx, [bp+@@sprite_id]
|
||
|
|
shl dx, 4 ; sprite_ptr = [sprite_id] * SPARK_SIZE
|
||
|
|
add ax, dx
|
||
|
|
add ax, offset sSPARKS
|
||
|
|
mov si, ax
|
||
|
|
mov cx, SPARK_H
|
||
|
|
|
||
|
|
@@blit_loop:
|
||
|
|
movsw
|
||
|
|
add di, (ROW_SIZE - SPARK_VRAM_W)
|
||
|
|
cmp di, (ROW_SIZE * RES_Y)
|
||
|
|
jl short @@next_row
|
||
|
|
sub di, (ROW_SIZE * RES_Y)
|
||
|
|
|
||
|
|
@@next_row:
|
||
|
|
loop @@blit_loop
|
||
|
|
pop di
|
||
|
|
pop si
|
||
|
|
pop bp
|
||
|
|
retn 6
|
||
|
|
spark_render endp
|
||
|
|
even
|