5f5771e823
Instead of having lots of duplicate code for drawing text to overlays and the background, move all of the actual drawing logic to a generic routine that can be used to draw text to *any* type of framebuffer.
127 lines
2.6 KiB
NASM
127 lines
2.6 KiB
NASM
; background routines
|
|
|
|
const BACKGROUND_FRAMEBUFFER: 0x80000000 ; pointer to background framebuffer
|
|
|
|
; fill the whole background with a color
|
|
; inputs:
|
|
; r0: color
|
|
; outputs:
|
|
; none
|
|
fill_background:
|
|
push r1
|
|
push r31
|
|
|
|
mov r1, BACKGROUND_FRAMEBUFFER
|
|
mov r31, 0x0004B000 ; 640*480
|
|
fill_background_loop:
|
|
mov [r1], r0
|
|
add r1, 4
|
|
loop fill_background_loop
|
|
|
|
pop r31
|
|
pop r1
|
|
ret
|
|
|
|
; draw a filled rectangle to the background
|
|
; inputs:
|
|
; r0: X coordinate of top-left
|
|
; r1: Y coordinate of top-left
|
|
; r2: X size
|
|
; r3: Y size
|
|
; r4: color
|
|
; outputs:
|
|
; none
|
|
draw_filled_rectangle_to_background:
|
|
push r0
|
|
push r1
|
|
push r2
|
|
push r3
|
|
push r4
|
|
push r5
|
|
push r6
|
|
|
|
; calculate pointer to the framebuffer
|
|
mul r1, 2560 ; y * 2560 (640 * 4 = 2560)
|
|
mul r0, 4 ; x * 4
|
|
add r0, r1 ; y * 2560 + (x * 4)
|
|
add r0, BACKGROUND_FRAMEBUFFER ; r0: pointer to framebuffer
|
|
|
|
mov r6, r2
|
|
mul r6, 4 ; multiply the X size by 4, since 4 bytes per pixel
|
|
|
|
draw_filled_rectangle_to_background_y_loop:
|
|
mov r5, r2 ; x counter
|
|
draw_filled_rectangle_to_background_x_loop:
|
|
mov [r0], r4
|
|
add r0, 4 ; increment framebuffer pointer
|
|
dec r5
|
|
ifnz jmp draw_filled_rectangle_to_background_x_loop ; loop if there are still more X pixels to draw
|
|
|
|
sub r0, r6 ; return to the beginning of this line
|
|
add r0, 2560 ; 640*4, increment to the next line
|
|
dec r3
|
|
ifnz jmp draw_filled_rectangle_to_background_y_loop ; loop if there are still more Y pixels to draw
|
|
|
|
pop r6
|
|
pop r5
|
|
pop r4
|
|
pop r3
|
|
pop r2
|
|
pop r1
|
|
pop r0
|
|
ret
|
|
|
|
; draw a single font tile to the background
|
|
; inputs:
|
|
; r0: tile number
|
|
; r1: X coordinate
|
|
; r2: Y coordinate
|
|
; r3: foreground color
|
|
; r4: background color
|
|
; outputs:
|
|
; none
|
|
draw_font_tile_to_background:
|
|
push r5
|
|
push r6
|
|
push r7
|
|
push r8
|
|
push r9
|
|
|
|
mov r5, standard_font_data
|
|
movz.16 r6, [standard_font_width]
|
|
movz.16 r7, [standard_font_height]
|
|
mov r8, BACKGROUND_FRAMEBUFFER
|
|
mov r9, 640
|
|
call draw_font_tile_generic
|
|
|
|
pop r9
|
|
pop r8
|
|
pop r7
|
|
pop r6
|
|
pop r5
|
|
ret
|
|
|
|
; draw text to the background
|
|
; inputs:
|
|
; r0: pointer to null-terminated string
|
|
; r1: X coordinate
|
|
; r2: Y coordinate
|
|
; r3: foreground color
|
|
; r4: background color
|
|
; outputs:
|
|
; r1: X coordinate of end of text
|
|
draw_str_to_background:
|
|
push r0
|
|
push r5
|
|
mov r5, r0
|
|
draw_str_to_background_loop:
|
|
movz.8 r0, [r5]
|
|
call draw_font_tile_to_background
|
|
inc r5
|
|
add r1, 8
|
|
cmp.8 [r5], 0x00
|
|
ifnz jmp draw_str_to_background_loop
|
|
pop r5
|
|
pop r0
|
|
ret
|