97 lines
1.1 KiB
ArmAsm
97 lines
1.1 KiB
ArmAsm
; VGI Triangles
|
|
|
|
SKIP = TEMP0
|
|
|
|
;========================
|
|
; VGI vertical triangle
|
|
;========================
|
|
|
|
VGI_TCOLOR = P0
|
|
VGI_VX = P1
|
|
VGI_VY = P2
|
|
VGI_TXL = P3
|
|
VGI_TXR = P4
|
|
VGI_TYB = P5
|
|
|
|
vgi_vertical_triangle:
|
|
lda VGI_TCOLOR
|
|
lsr
|
|
lsr
|
|
lsr
|
|
lsr
|
|
sta SKIP
|
|
|
|
lda VGI_TCOLOR
|
|
and #$f
|
|
tax
|
|
lda COLORTBL,X
|
|
sta HGR_COLOR
|
|
|
|
vtri_loop:
|
|
ldy #0
|
|
ldx VGI_VX
|
|
lda VGI_VY
|
|
|
|
jsr HPLOT0 ; plot at (Y,X), (A)
|
|
|
|
|
|
ldx #0
|
|
ldy VGI_TYB
|
|
lda VGI_TXL
|
|
|
|
jsr HGLIN ; line to (X,A),(Y)
|
|
|
|
lda VGI_TXL
|
|
clc
|
|
adc SKIP
|
|
sta VGI_TXL
|
|
; inc VGI_TXL
|
|
; lda VGI_TXL
|
|
cmp VGI_TXR
|
|
bcc vtri_loop
|
|
|
|
done_vtri:
|
|
jmp vgi_loop ; bra
|
|
|
|
|
|
|
|
;========================
|
|
; VGI horizontal triangle
|
|
;========================
|
|
|
|
; VGI_TCOLOR = P0
|
|
; VGI_VX = P1
|
|
; VGI_VY = P2
|
|
VGI_THYT = P3
|
|
VGI_THYB = P4
|
|
VGI_THXR = P5
|
|
|
|
vgi_horizontal_triangle:
|
|
|
|
ldx VGI_TCOLOR
|
|
lda COLORTBL,X
|
|
sta HGR_COLOR
|
|
|
|
htri_loop:
|
|
ldy #0
|
|
ldx VGI_VX
|
|
lda VGI_VY
|
|
|
|
jsr HPLOT0 ; plot at (Y,X), (A)
|
|
|
|
|
|
ldx #0
|
|
ldy VGI_THYT
|
|
lda VGI_THXR
|
|
|
|
jsr HGLIN ; line to (X,A),(Y)
|
|
|
|
inc VGI_THYT
|
|
lda VGI_THYT
|
|
cmp VGI_THYB
|
|
bcc htri_loop
|
|
|
|
done_htri:
|
|
jmp vgi_loop
|
|
|