fox32rom: Start implementing a basic string formatting system

background.asm

@@ -73,6 +73,37 @@ draw_font_tile_to_background:
     pop r5
     ret
 
+; draw text to the background, using printf-style formatting
+; inputs:
+; r0: pointer to null-terminated string
+; r1: X coordinate
+; r2: Y coordinate
+; r3: foreground color
+; r4: background color
+; r10-r15: optional format values
+; outputs:
+; r1: X coordinate of end of text
+draw_format_str_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_format_str_generic
+
+    pop r9
+    pop r8
+    pop r7
+    pop r6
+    pop r5
+    ret
+
 ; draw text to the background
 ; inputs:
 ; r0: pointer to null-terminated string

draw_text.asm

@@ -81,6 +81,114 @@ draw_font_tile_generic_x_loop_end:
     pop r0
     ret
 
+; draw text to a framebuffer, using printf-style formatting
+; inputs:
+; r0: pointer to null-terminated string
+; r1: X coordinate
+; r2: Y coordinate
+; r3: foreground color
+; r4: background color
+; r5: pointer to font graphics
+; r6: font width
+; r7: font height
+; r8: pointer to framebuffer
+; r9: framebuffer width
+; r10-r15: optional format values
+; outputs:
+; r1: X coordinate of end of text
+draw_format_str_generic:
+    push r0
+    push r1
+    push r2
+    push r5
+    push r6
+    push r7
+    push r8
+    push r9
+    push r16
+    push r17
+
+    mov r16, 0               ; current format specifier counter
+draw_format_str_generic_loop:
+    cmp.8 [r0], 0
+    ifz jmp draw_format_str_generic_end
+    cmp.8 [r0], '\'
+    ifz jmp draw_format_str_generic_found_format_specifier
+
+    ; if this is not a format specifier or the end of the string, print the character
+    push r0
+    movz.8 r0, [r0]
+    call draw_font_tile_generic
+    pop r0
+    add r1, r6               ; add the font width to the X coordinate
+
+    inc r0
+    jmp draw_format_str_generic_loop
+draw_format_str_generic_found_format_specifier:
+    inc r0
+
+    ; unsigned decimal
+    cmp.8 [r0], 'u'
+    ifz call draw_format_str_generic_unsigned_decimal
+
+    inc r0
+    jmp draw_format_str_generic_loop
+draw_format_str_generic_unsigned_decimal:
+    call draw_format_str_generic_get_parameter
+    push r0
+    mov r0, r17
+    call draw_decimal_generic
+    pop r0
+    inc r16
+    ret
+draw_format_str_generic_get_parameter:
+    ; load the correct format parameter into r17
+    ; this is messy, but i don't know of any other way to do this at the moment
+    cmp r16, 0
+    ifz jmp draw_format_str_generic_get_parameter_0
+    cmp r16, 1
+    ifz jmp draw_format_str_generic_get_parameter_1
+    cmp r16, 2
+    ifz jmp draw_format_str_generic_get_parameter_2
+    cmp r16, 3
+    ifz jmp draw_format_str_generic_get_parameter_3
+    cmp r16, 4
+    ifz jmp draw_format_str_generic_get_parameter_4
+    cmp r16, 5
+    ifz jmp draw_format_str_generic_get_parameter_5
+    mov r17, 0
+    ret
+draw_format_str_generic_get_parameter_0:
+    mov r17, r10
+    ret
+draw_format_str_generic_get_parameter_1:
+    mov r17, r11
+    ret
+draw_format_str_generic_get_parameter_2:
+    mov r17, r12
+    ret
+draw_format_str_generic_get_parameter_3:
+    mov r17, r13
+    ret
+draw_format_str_generic_get_parameter_4:
+    mov r17, r14
+    ret
+draw_format_str_generic_get_parameter_5:
+    mov r17, r15
+    ret
+draw_format_str_generic_end:
+    pop r17
+    pop r16
+    pop r9
+    pop r8
+    pop r7
+    pop r6
+    pop r5
+    pop r2
+    pop r1
+    pop r0
+    ret
+
 ; draw text to a framebuffer
 ; inputs:
 ; r0: pointer to null-terminated string

fox32rom.def

@@ -10,26 +10,29 @@ get_next_event:                           jmp [0xF0040014]
 
 ; generic drawing jump table
 draw_str_generic:                         jmp [0xF0041000]
-draw_decimal_generic:                     jmp [0xF0041004]
-draw_font_tile_generic:                   jmp [0xF0041008]
-draw_filled_rectangle_generic:            jmp [0xF004100C]
+draw_format_str_generic:                  jmp [0xF0041004]
+draw_decimal_generic:                     jmp [0xF0041008]
+draw_font_tile_generic:                   jmp [0xF004100C]
+draw_filled_rectangle_generic:            jmp [0xF0041010]
 
 ; background jump table entries
 fill_background:                          jmp [0xF0042000]
 draw_str_to_background:                   jmp [0xF0042004]
-draw_decimal_to_background:               jmp [0xF0042008]
-draw_font_tile_to_background:             jmp [0xF004200C]
-draw_filled_rectangle_to_background:      jmp [0xF0042010]
+draw_format_str_to_background:            jmp [0xF0042008]
+draw_decimal_to_background:               jmp [0xF004200C]
+draw_font_tile_to_background:             jmp [0xF0042010]
+draw_filled_rectangle_to_background:      jmp [0xF0042014]
 
 ; overlay jump table entries
 fill_overlay:                             jmp [0xF0043000]
 draw_str_to_overlay:                      jmp [0xF0043004]
-draw_decimal_to_overlay:                  jmp [0xF0043008]
-draw_font_tile_to_overlay:                jmp [0xF004300C]
-draw_filled_rectangle_to_overlay:         jmp [0xF0043010]
-find_overlay_covering_position:           jmp [0xF0043014]
-check_if_overlay_covers_position:         jmp [0xF0043018]
-check_if_enabled_overlay_covers_position: jmp [0xF004301C]
+draw_format_str_to_overlay:               jmp [0xF0043008]
+draw_decimal_to_overlay:                  jmp [0xF004300C]
+draw_font_tile_to_overlay:                jmp [0xF0043010]
+draw_filled_rectangle_to_overlay:         jmp [0xF0043014]
+find_overlay_covering_position:           jmp [0xF0043018]
+check_if_overlay_covers_position:         jmp [0xF004301C]
+check_if_enabled_overlay_covers_position: jmp [0xF0043020]
 
 ; menu bar jump table entries
 menu_bar_click_event:                     jmp [0xF0044000]

main.asm

@@ -201,6 +201,7 @@ get_rom_version:
     ; generic drawing jump table
     org.pad 0xF0041000
     data.32 draw_str_generic
+    data.32 draw_format_str_generic
     data.32 draw_decimal_generic
     data.32 draw_font_tile_generic
     data.32 draw_filled_rectangle_generic
@@ -209,6 +210,7 @@ get_rom_version:
     org.pad 0xF0042000
     data.32 fill_background
     data.32 draw_str_to_background
+    data.32 draw_format_str_to_background
     data.32 draw_decimal_to_background
     data.32 draw_font_tile_to_background
     data.32 draw_filled_rectangle_to_background
@@ -217,6 +219,7 @@ get_rom_version:
     org.pad 0xF0043000
     data.32 fill_overlay
     data.32 draw_str_to_overlay
+    data.32 draw_format_str_to_overlay
     data.32 draw_decimal_to_overlay
     data.32 draw_font_tile_to_overlay
     data.32 draw_filled_rectangle_to_overlay

overlay.asm

@@ -96,6 +96,43 @@ draw_font_tile_to_overlay:
     pop r5
     ret
 
+; draw text to an overlay, using printf-style formatting
+; inputs:
+; r0: pointer to null-terminated string
+; r1: X coordinate
+; r2: Y coordinate
+; r3: foreground color
+; r4: background color
+; r5: overlay number
+; r10-r15: optional format values
+; outputs:
+; r1: X coordinate of end of text
+draw_format_str_to_overlay:
+    push r5
+    push r6
+    push r7
+    push r8
+    push r9
+
+    mov r6, r5
+    or r6, 0x80000100        ; bitwise or the overlay number with the command to get the overlay size
+    or r5, 0x80000200        ; bitwise or the overlay number with the command to get the framebuffer pointer
+    in r8, r5                ; r8: overlay framebuffer poiner
+    in r9, r6
+    and r9, 0x0000FFFF       ; r9: overlay width
+
+    mov r5, standard_font_data
+    movz.16 r6, [standard_font_width]
+    movz.16 r7, [standard_font_height]
+    call draw_format_str_generic
+
+    pop r9
+    pop r8
+    pop r7
+    pop r6
+    pop r5
+    ret
+
 ; draw text to an overlay
 ; inputs:
 ; r0: pointer to null-terminated string