553 lines
10 KiB
ArmAsm
553 lines
10 KiB
ArmAsm
;=====================================================================
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;= ROUTINES
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;=====================================================================
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clear_screens:
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;===================================
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; Clear top/bottom of page 0
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;===================================
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lda #$0
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sta DRAW_PAGE
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jsr clear_top
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jsr clear_bottom
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;===================================
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; Clear top/bottom of page 1
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;===================================
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lda #$4
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sta DRAW_PAGE
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jsr clear_top
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jsr clear_bottom
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rts
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;==========
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; page_flip
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;==========
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page_flip:
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lda DISP_PAGE ; 3
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beq page_flip_show_1 ; 2nt/3
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page_flip_show_0:
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bit PAGE0 ; 4
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lda #4 ; 2
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sta DRAW_PAGE ; DRAW_PAGE=1 ; 3
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lda #0 ; 2
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sta DISP_PAGE ; DISP_PAGE=0 ; 3
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rts ; 6
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page_flip_show_1:
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bit PAGE1 ; 4
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sta DRAW_PAGE ; DRAW_PAGE=0 ; 3
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lda #1 ; 2
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sta DISP_PAGE ; DISP_PAGE=1 ; 3
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rts ; 6
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;====================
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; DISP_PAGE=0 26
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; DISP_PAGE=1 24
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;======================
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; memset
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;======================
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; a=value
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; x=length
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; MEMPTRL/MEMPTRH is address
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memset:
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ldy #0
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memset_loop:
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sta MEMPTRL,Y
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iny
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dex
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bne memset_loop
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rts
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;==========================================================
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; set_gr_page0
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;==========================================================
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;
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set_gr_page0:
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;lda #4
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;sta GR_PAGE
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bit PAGE0 ; set page 0
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bit LORES ; Lo-res graphics
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bit TEXTGR ; mixed gr/text mode
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bit SET_GR ; set graphics
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rts
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;==========================================================
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; Wait until keypressed
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;==========================================================
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;
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wait_until_keypressed:
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lda KEYPRESS ; check if keypressed
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bpl wait_until_keypressed ; if not, loop
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jmp figure_out_key
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;==========================================================
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; Get Key
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;==========================================================
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;
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get_key:
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check_paddle_button:
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; check for paddle button
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bit PADDLE_BUTTON0 ; 4
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bpl no_button ; 2nt/3
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lda #' '+128 ; 2
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jmp save_key ; 3
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no_button:
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lda KEYPRESS ; 3
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bpl no_key ; 2nt/3
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figure_out_key:
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cmp #' '+128 ; the mask destroys space ; 2
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beq save_key ; so handle it specially ; 2nt/3
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and #$5f ; mask, to make upper-case ; 2
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check_right_arrow:
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cmp #$15 ; 2
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bne check_left_arrow ; 2nt/3
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lda #'D' ; 2
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check_left_arrow:
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cmp #$08 ; 2
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bne check_up_arrow ; 2nt/3
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lda #'A' ; 2
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check_up_arrow:
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cmp #$0B ; 2
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bne check_down_arrow ; 2nt/3
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lda #'W' ; 2
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check_down_arrow:
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cmp #$0A ; 2
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bne check_escape ; 2nt/3
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lda #'S' ; 2
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check_escape:
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cmp #$1B ; 2
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bne save_key ; 2nt/3
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lda #'Q' ; 2
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jmp save_key ; 3
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no_key:
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bit PADDLE_STATUS ; 3
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bpl no_key_store ; 2nt/3
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; check for paddle action
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; code from http://web.pdx.edu/~heiss/technotes/aiie/tn.aiie.06.html
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inc PADDLE_STATUS ; 5
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lda PADDLE_STATUS ; 3
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and #$03 ; 2
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beq check_paddles ; 2nt/3
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jmp no_key_store ; 3
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check_paddles:
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lda PADDLE_STATUS ; 3
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and #$80 ; 2
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sta PADDLE_STATUS ; 3
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ldx #$0 ; 2
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LDA PTRIG ;TRIGGER PADDLES ; 4
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LDY #0 ;INIT COUNTER ; 2
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NOP ;COMPENSATE FOR 1ST COUNT ; 2
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NOP ; 2
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PREAD2: LDA PADDL0,X ;COUNT EVERY 11 uSEC. ; 4
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BPL RTS2D ;BRANCH WHEN TIMED OUT ; 2nt/3
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INY ;INCREMENT COUNTER ; 2
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BNE PREAD2 ;CONTINUE COUNTING ; 2nt/3
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DEY ;COUNTER OVERFLOWED ; 2
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RTS2D: ;RETURN W/VALUE 0-255
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cpy #96 ; 2
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bmi paddle_left ; 2nt/3
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cpy #160 ; 2
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bmi no_key_store ; 2nt/3
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lda #'D' ; 2
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jmp save_key ; 3
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paddle_left:
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lda #'A' ; 2
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jmp save_key ; 3
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no_key_store:
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lda #0 ; no key, so save a zero ; 2
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save_key:
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sta LASTKEY ; save the key to our buffer ; 2
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bit KEYRESET ; clear the keyboard buffer ; 4
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rts ; 6
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;============
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; 33=nokey
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; 48=worstkey
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;=============================================
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; put_sprite
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;=============================================
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; Sprite to display in INH,INL
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; Location is XPOS,YPOS
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; Note, only works if YPOS is multiple of two?
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put_sprite:
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ldy #0 ; byte 0 is xsize ; 2
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lda (INL),Y ; 5
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sta CH ; xsize is in CH ; 3
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iny ; 2
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lda (INL),Y ; byte 1 is ysize ; 5
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sta CV ; ysize is in CV ; 3
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iny ; 2
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lda YPOS ; make a copy of ypos ; 3
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sta TEMPY ; as we modify it ; 3
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;===========
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; 28
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put_sprite_loop:
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sty TEMP ; save sprite pointer ; 3
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ldy TEMPY ; 3
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lda gr_offsets,Y ; lookup low-res memory address ; 5
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clc ; 2
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adc XPOS ; add in xpos ; 3
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sta OUTL ; store out low byte of addy ; 3
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lda gr_offsets+1,Y ; look up high byte ; 5
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adc DRAW_PAGE ; ; 3
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sta OUTH ; and store it out ; 3
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ldy TEMP ; restore sprite pointer ; 3
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; OUTH:OUTL now points at right place
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ldx CH ; load xsize into x ; 3
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;===========
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; 36
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put_sprite_pixel:
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lda (INL),Y ; get sprite colors ; 5
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iny ; increment sprite pointer ; 2
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sty TEMP ; save sprite pointer ; 3
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ldy #$0 ; 2
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; check if completely transparent
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; if so, skip
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cmp #$0 ; if all zero, transparent ; 2
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beq put_sprite_done_draw ; don't draw it ; 2nt/3
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; FIXME: use BIT? ;==============
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; 17
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sta COLOR ; save color for later ; 3
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; check if top pixel transparent
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and #$f0 ; check if top nibble zero ; 2
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bne put_sprite_bottom ; if not skip ahead ; 2nt/3
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lda #$f0 ; setup mask ; 2
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sta MASK ; 3
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bmi put_sprite_mask ; 2nt/3
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put_sprite_bottom:
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lda COLOR ; re-load color ; 3
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and #$0f ; check if bottom nibble zero ; 2
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bne put_sprite_all ; if not, skip ahead ; 2nt/3
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lda #$0f ; 2
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sta MASK ; setup mask ; 3
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put_sprite_mask:
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lda (OUTL),Y ; get color at output ; 5
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and MASK ; mask off unneeded part ; 3
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ora COLOR ; or the color in ; 3
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sta (OUTL),Y ; store it back ; 5
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jmp put_sprite_done_draw ; we are done ; 3
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put_sprite_all:
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lda COLOR ; load color ; 3
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sta (OUTL),Y ; and write it out ; 5
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put_sprite_done_draw:
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ldy TEMP ; restore sprite pointer ; 3
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inc OUTL ; increment output pointer ; 5
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dex ; decrement x counter ; 2
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bne put_sprite_pixel ; if not done, keep looping ; 2nt/3
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inc TEMPY ; each line has two y vars ; 5
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inc TEMPY ; 5
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dec CV ; decemenet total y count ; 5
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bne put_sprite_loop ; loop if not done ; 2nt/3
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rts ; return ; 6
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;================================
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; htab_vtab
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;================================
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; move to CH/CV
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htab_vtab:
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lda CV
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asl
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tay
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lda gr_offsets,Y ; lookup low-res memory address
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clc
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adc CH ; add in xpos
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sta BASL ; store out low byte of addy
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lda gr_offsets+1,Y ; look up high byte
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adc DRAW_PAGE ;
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sta BASH ; and store it out
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; BASH:BASL now points at right place
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rts
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;================================
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; move_and_print
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;================================
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; move to CH/CV
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move_and_print:
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jsr htab_vtab
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;================================
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; print_string
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;================================
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print_string:
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ldy #0
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print_string_loop:
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lda (OUTL),Y
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beq done_print_string
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ora #$80
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sta (BASL),Y
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iny
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bne print_string_loop
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done_print_string:
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rts
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;====================
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; point_to_end_string
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;====================
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point_to_end_string:
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iny
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tya
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clc
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adc OUTL
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sta OUTL
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lda #0
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adc OUTH
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sta OUTH
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rts
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;================================
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; print_both_pages
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;================================
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print_both_pages:
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lda DRAW_PAGE
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pha
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lda #0
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sta DRAW_PAGE
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jsr move_and_print
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lda #4
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sta DRAW_PAGE
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jsr move_and_print
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pla
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sta DRAW_PAGE
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rts ; oops forgot this initially
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; explains the weird vertical stripes on the screen
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;================================
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; hlin_setup
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;================================
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; put address in GBASL/GBASH
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; Ycoord in A, Xcoord in Y
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hlin_setup:
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sty TEMPY ; 3
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tay ; y=A ; 2
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lda gr_offsets,Y ; lookup low-res memory address ; 4
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clc ; 2
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adc TEMPY ; 3
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sta GBASL ; 3
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iny ; 2
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lda gr_offsets,Y ; 4
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adc DRAW_PAGE ; add in draw page offset ; 3
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sta GBASH ; 3
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rts ; 6
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;===========
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; 35
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;================================
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; hlin_double:
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;================================
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; HLIN Y, V2 AT A
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; Y, X, A trashed
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; start at Y, draw up to and including X
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hlin_double:
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;int hlin_double(int page, int x1, int x2, int at) {
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jsr hlin_setup ; 41
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sec ; 2
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lda V2 ; 3
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sbc TEMPY ; 3
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tax ; 2
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inx ; 2
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;===========
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; 53
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; fallthrough
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;=================================
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; hlin_double_continue: width
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;=================================
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; width in X
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hlin_double_continue:
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ldy #0 ; 2
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lda COLOR ; 3
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hlin_double_loop:
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sta (GBASL),Y ; 6
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inc GBASL ; 5
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dex ; 2
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bne hlin_double_loop ; 2nt/3
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rts ; 6
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;=============
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; 53+5+X*16+5
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;================================
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; hlin_single:
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;================================
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; HLIN Y, V2 AT A
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; Y, X, A trashed
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hlin_single:
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jsr hlin_setup
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sec
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lda V2
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sbc TEMPY
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tax
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; fallthrough
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;=================================
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; hlin_single_continue: width
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;=================================
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; width in X
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hlin_single_continue:
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hlin_single_top:
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lda COLOR
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and #$f0
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sta COLOR
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hlin_single_top_loop:
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ldy #0
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lda (GBASL),Y
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and #$0f
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ora COLOR
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sta (GBASL),Y
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inc GBASL
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dex
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bne hlin_single_top_loop
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rts
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hlin_single_bottom:
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lda COLOR
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and #$0f
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sta COLOR
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hlin_single_bottom_loop:
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ldy #0
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lda (GBASL),Y
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and #$f0
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sta (GBASL),Y
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inc GBASL
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dex
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bne hlin_single_bottom_loop
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rts
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;=============================
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; clear_top
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;=============================
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clear_top:
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lda #$00
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;=============================
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; clear_top_a
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;=============================
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clear_top_a:
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sta COLOR
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; VLIN Y, V2 AT A
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lda #40
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sta V2
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lda #0
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clear_top_loop:
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ldy #0
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pha
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jsr hlin_double
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pla
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clc
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adc #$2
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cmp #40
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bne clear_top_loop
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rts
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clear_bottom:
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lda #$a0 ; NORMAL space
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sta COLOR
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lda #40
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sta V2
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clear_bottom_loop:
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ldy #0
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pha
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jsr hlin_double
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pla
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clc
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adc #$2
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cmp #48
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bne clear_bottom_loop
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rts
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; move these to zero page for slight speed increase?
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gr_offsets:
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.word $400,$480,$500,$580,$600,$680,$700,$780
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.word $428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
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.word $450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0
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