Gameboy Development Forum

I read the PanDocs about windows and I've got my answer... Apparently I can't display a custom sized window since it cover all the background so I will just use sprites. Never use them before, I'm a bit scared.

So technically, I can make a custom sized window ?

I mean, if I place my window at the bottom of the screen and make it flash by enable/disable the window on [rLCDC], it will work ?

I want it to work like the picture below (the window is in the red rectangle)

Last edited by Glad (2016-01-10 11:59:34)

So I load a 20*18 tiles window and put the upper lft corner at the bottom of my screen and it will work ?

So I've been able to move my windows at the bottom like I wanted but there's some glitchs at the top now...

For displaying the BG, I put this in [rLCDC] : %11010001

And when I need my window to pop, I write this in [rLCDC] : %1111001

I've read the pandoc and the gameboy programming guide but I can't find out where I'm wrong !
Maybe It's a problem with the bit 4 for the BG and window tile data selection...

here is the two function for displaying the main menu screen and the window :

Main_Menu:

di
call LCD_Off
xor A
ld [rSCX],A
ld [rSCY],A
ld HL, Menu_Tiles
ld DE,$95 * $10            ;Chargement de 146 tiles
call Load_Tiles_Into_VRAM

ld HL,Menu_Map
call Screen_Load_0_20x18

ld A,%11010001             ;BG On -
ld [rLCDC],A
ei
call Fade_In_Black

ret

SECTION "Press_Start_Window",HOME

Press_Start_Window:
di
call LCD_Off
ld A,7
ld [rWX],A
ld A, $6D
ld [rWY],A
ld HL, Press_Start_Tiles
ld DE,$1B * $10            ;Chargement de 27 tiles
call Load_Tiles_Into_VRAM

ld HL,Press_Start_Map
call Screen_Load_1_20x18

ld A,%11110001             ;Window+BG On
ld [rLCDC],A
ei

ret

and here's the sub fonctions for loading the screen and loading the window

Screen_Load_0_20x18:
   ld DE,18                   ;this many y-lines.
   ld BC,_SCRN0-(12)          ;background tile map 0. subtracting 12, as it'll be added in again soon.
.y_line_loop
   push DE                    ;Storing the Y-Line coord for later.
   ld DE,12                   ;first, we need to increase _SCRN0 location by 12*16, and ignore all the tiles off screen
.inc_bgmap_location
   inc BC
   dec DE
   ld A,E
   or D
   jp nz,.inc_bgmap_location
   
   ld DE,20          ;x-length, 20 tiles at 16 bytes each
.x_line_loop
   ld A,[HL+]        ;where the magic happens
   ld [BC],A
   inc BC
   dec DE
   ld A,E
   or D
   jp nz,.x_line_loop

   pop DE            ;after we've got done loading an x-line, we need to check our y-line
   dec DE
   ld A,E
   or D
   jp nz,.y_line_loop
   ret

     SECTION "20x18 Screen Load 1",HOME
   ;Used for loading a map into the BG map area at $9800 that is 20x18 tiles.
   ;HL must be at the start of the tile data.
   ;Assumes rSCX & rSCY are at 0,0.
Screen_Load_1_20x18:
   ld DE,18                   ;this many y-lines.
   ld BC,_SCRN1-(12)          ;background tile map 1. subtracting 12, as it'll be added in again soon.
.y_line_loop_w
   push DE           ;Storing the Y-Line coord for later.
   ld DE,12          ;first, we need to increase _SCRN1 location by 12*16, and ignore all the tiles off screen
.inc_winmap_location
   inc BC
   dec DE
   ld A,E
   or D
   jp nz,.inc_winmap_location
   
   ld DE,20          ;x-length, 20 tiles at 16 bytes each
.x_line_loop_w
   ld A,[HL+]        ;where the magic happens
   ld [BC],A
   inc BC
   dec DE
   ld A,E
   or D
   jp nz,.x_line_loop_w

   pop DE            ;after we've got done loading an x-line, we need to check our y-line
   dec DE
   ld A,E
   or D
   jp nz,.y_line_loop_w
   ret

I use some sample of your SuperHappyFunBubbleTime project for doing this !

Last edited by Glad (2016-01-10 21:51:04)

Thank you very much L0k1 ! I will try to load all the tiles together and see if it's change something. If it don't I will go for the sprites !

Awesome! Happy you got it working.

grumpily gets back to working on his own bugs

Last edited by l0k1 (2016-01-12 03:26:31)