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Merge pull request #300 from boriel/feature/allow_setting_PLOT_coords
Allow shifting X,Y screen coords
2 parents c5e997b + 2b83d5d commit e2f7546

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10 files changed

+687
-1901
lines changed

10 files changed

+687
-1901
lines changed

‎library-asm/circle.asm‎

Lines changed: 186 additions & 182 deletions
Original file line numberDiff line numberDiff line change
@@ -8,206 +8,210 @@
88
; Draws a circle at X, Y of radius R
99
; X, Y on the Stack, R in accumulator (Byte)
1010

11-
PROC
12-
LOCAL __CIRCLE_ERROR
13-
LOCAL __CIRCLE_LOOP
14-
LOCAL __CIRCLE_NEXT
11+
PROC
12+
LOCAL __CIRCLE_ERROR
13+
LOCAL __CIRCLE_LOOP
14+
LOCAL __CIRCLE_NEXT
1515

1616
__CIRCLE_ERROR:
1717
jp __OUT_OF_SCREEN_ERR
18-
;; __CIRCLE_ERROR EQU __OUT_OF_SCREEN_ERR
19-
;; __CIRCLE_ERROR:
20-
;; ; Jumps here if out of screen
21-
;; scf ; Always sets carry Flag
22-
;;
23-
;; ld a, ERROR_OutOfScreen
24-
;; ld (ERR_NR), a
25-
;; ret
2618
CIRCLE:
2719
;; Entry point
28-
pop hl ; Return Address
29-
pop de ; D = Y
30-
ex (sp), hl ; __CALLEE__ convention
31-
ld e, h ; E = X
32-
33-
34-
ld h, a ; H = R
35-
add a, d
36-
sub 192
37-
jr nc, __CIRCLE_ERROR
38-
39-
ld a, d
40-
sub h
41-
jr c, __CIRCLE_ERROR
42-
43-
ld a, e
44-
sub h
45-
jr c, __CIRCLE_ERROR
46-
47-
ld a, h
48-
add a, e
49-
jr c, __CIRCLE_ERROR
20+
pop hl ; Return Address
21+
pop de ; D = Y
22+
ex (sp), hl ; __CALLEE__ convention
23+
ld e, h ; E = X
24+
ld h, a ; H = R
25+
26+
#ifdef SCREEN_Y_OFFSET
27+
ld a, SCREEN_Y_OFFSET
28+
add a, d
29+
ld d, a
30+
#endif
31+
32+
#ifdef SCREEN_X_OFFSET
33+
ld a, SCREEN_X_OFFSET
34+
add a, e
35+
ld e, a
36+
#endif
37+
38+
ld a, h
39+
add a, d
40+
sub 192
41+
jr nc, __CIRCLE_ERROR
42+
43+
ld a, d
44+
sub h
45+
jr c, __CIRCLE_ERROR
46+
47+
ld a, e
48+
sub h
49+
jr c, __CIRCLE_ERROR
50+
51+
ld a, h
52+
add a, e
53+
jr c, __CIRCLE_ERROR
5054

5155

5256
; __FASTCALL__ Entry: D, E = Y, X point of the center
5357
; A = Radious
5458
__CIRCLE:
55-
push de
56-
ld a, h
57-
exx
58-
pop de ; D'E' = x0, y0
59-
ld h, a ; H' = r
60-
61-
ld c, e
62-
ld a, h
63-
add a, d
64-
ld b, a
65-
call __CIRCLE_PLOT ; PLOT (x0, y0 + r)
66-
67-
ld b, d
68-
ld a, h
69-
add a, e
70-
ld c, a
71-
call __CIRCLE_PLOT ; PLOT (x0 + r, y0)
72-
73-
ld c, e
74-
ld a, d
75-
sub h
76-
ld b, a
77-
call __CIRCLE_PLOT ; PLOT (x0, y0 - r)
78-
79-
ld b, d
80-
ld a, e
81-
sub h
82-
ld c, a
83-
call __CIRCLE_PLOT ; PLOT (x0 - r, y0)
84-
85-
exx
86-
ld b, 0 ; B = x = 0
87-
ld c, h ; C = y = Radius
88-
ld hl, 1
89-
or a
90-
sbc hl, bc ; HL = f = 1 - radius
91-
92-
ex de, hl
93-
ld hl, 0
94-
or a
95-
sbc hl, bc ; HL = -radius
96-
add hl, hl ; HL = -2 * radius
97-
ex de, hl ; DE = -2 * radius = ddF_y, HL = f
98-
99-
xor a ; A = ddF_x = 0
100-
ex af, af' ; Saves it
59+
push de
60+
ld a, h
61+
exx
62+
pop de ; D'E' = x0, y0
63+
ld h, a ; H' = r
64+
65+
ld c, e
66+
ld a, h
67+
add a, d
68+
ld b, a
69+
call __CIRCLE_PLOT ; PLOT (x0, y0 + r)
70+
71+
ld b, d
72+
ld a, h
73+
add a, e
74+
ld c, a
75+
call __CIRCLE_PLOT ; PLOT (x0 + r, y0)
76+
77+
ld c, e
78+
ld a, d
79+
sub h
80+
ld b, a
81+
call __CIRCLE_PLOT ; PLOT (x0, y0 - r)
82+
83+
ld b, d
84+
ld a, e
85+
sub h
86+
ld c, a
87+
call __CIRCLE_PLOT ; PLOT (x0 - r, y0)
88+
89+
exx
90+
ld b, 0 ; B = x = 0
91+
ld c, h ; C = y = Radius
92+
ld hl, 1
93+
or a
94+
sbc hl, bc ; HL = f = 1 - radius
95+
96+
ex de, hl
97+
ld hl, 0
98+
or a
99+
sbc hl, bc ; HL = -radius
100+
add hl, hl ; HL = -2 * radius
101+
ex de, hl ; DE = -2 * radius = ddF_y, HL = f
102+
103+
xor a ; A = ddF_x = 0
104+
ex af, af' ; Saves it
101105

102106
__CIRCLE_LOOP:
103-
ld a, b
104-
cp c
105-
ret nc ; Returns when x >= y
107+
ld a, b
108+
cp c
109+
ret nc ; Returns when x >= y
106110

107-
bit 7, h ; HL >= 0? : if (f >= 0)...
108-
jp nz, __CIRCLE_NEXT
111+
bit 7, h ; HL >= 0? : if (f >= 0)...
112+
jp nz, __CIRCLE_NEXT
109113

110-
dec c ; y--
111-
inc de
112-
inc de ; ddF_y += 2
114+
dec c ; y--
115+
inc de
116+
inc de ; ddF_y += 2
113117

114-
add hl, de ; f += ddF_y
118+
add hl, de ; f += ddF_y
115119

116120
__CIRCLE_NEXT:
117-
inc b ; x++
118-
ex af, af'
119-
add a, 2 ; 1 Cycle faster than inc a, inc a
120-
121-
inc hl ; f++
122-
push af
123-
add a, l
124-
ld l, a
125-
ld a, h
126-
adc a, 0 ; f = f + ddF_x
127-
ld h, a
128-
pop af
129-
ex af, af'
130-
131-
push bc
132-
exx
133-
pop hl ; H'L' = Y, X
134-
135-
ld a, d
136-
add a, h
137-
ld b, a ; B = y0 + y
138-
ld a, e
139-
add a, l
140-
ld c, a ; C = x0 + x
141-
call __CIRCLE_PLOT ; plot(x0 + x, y0 + y)
142-
143-
ld a, d
144-
add a, h
145-
ld b, a ; B = y0 + y
146-
ld a, e
147-
sub l
148-
ld c, a ; C = x0 - x
149-
call __CIRCLE_PLOT ; plot(x0 - x, y0 + y)
150-
151-
ld a, d
152-
sub h
153-
ld b, a ; B = y0 - y
154-
ld a, e
155-
add a, l
156-
ld c, a ; C = x0 + x
157-
call __CIRCLE_PLOT ; plot(x0 + x, y0 - y)
158-
159-
ld a, d
160-
sub h
161-
ld b, a ; B = y0 - y
162-
ld a, e
163-
sub l
164-
ld c, a ; C = x0 - x
165-
call __CIRCLE_PLOT ; plot(x0 - x, y0 - y)
166-
167-
ld a, d
168-
add a, l
169-
ld b, a ; B = y0 + x
170-
ld a, e
171-
add a, h
172-
ld c, a ; C = x0 + y
173-
call __CIRCLE_PLOT ; plot(x0 + y, y0 + x)
174-
175-
ld a, d
176-
add a, l
177-
ld b, a ; B = y0 + x
178-
ld a, e
179-
sub h
180-
ld c, a ; C = x0 - y
181-
call __CIRCLE_PLOT ; plot(x0 - y, y0 + x)
182-
183-
ld a, d
184-
sub l
185-
ld b, a ; B = y0 - x
186-
ld a, e
187-
add a, h
188-
ld c, a ; C = x0 + y
189-
call __CIRCLE_PLOT ; plot(x0 + y, y0 - x)
190-
191-
ld a, d
192-
sub l
193-
ld b, a ; B = y0 - x
194-
ld a, e
195-
sub h
196-
ld c, a ; C = x0 + y
197-
call __CIRCLE_PLOT ; plot(x0 - y, y0 - x)
198-
199-
exx
200-
jp __CIRCLE_LOOP
121+
inc b ; x++
122+
ex af, af'
123+
add a, 2 ; 1 Cycle faster than inc a, inc a
124+
125+
inc hl ; f++
126+
push af
127+
add a, l
128+
ld l, a
129+
ld a, h
130+
adc a, 0 ; f = f + ddF_x
131+
ld h, a
132+
pop af
133+
ex af, af'
134+
135+
push bc
136+
exx
137+
pop hl ; H'L' = Y, X
138+
139+
ld a, d
140+
add a, h
141+
ld b, a ; B = y0 + y
142+
ld a, e
143+
add a, l
144+
ld c, a ; C = x0 + x
145+
call __CIRCLE_PLOT ; plot(x0 + x, y0 + y)
146+
147+
ld a, d
148+
add a, h
149+
ld b, a ; B = y0 + y
150+
ld a, e
151+
sub l
152+
ld c, a ; C = x0 - x
153+
call __CIRCLE_PLOT ; plot(x0 - x, y0 + y)
154+
155+
ld a, d
156+
sub h
157+
ld b, a ; B = y0 - y
158+
ld a, e
159+
add a, l
160+
ld c, a ; C = x0 + x
161+
call __CIRCLE_PLOT ; plot(x0 + x, y0 - y)
162+
163+
ld a, d
164+
sub h
165+
ld b, a ; B = y0 - y
166+
ld a, e
167+
sub l
168+
ld c, a ; C = x0 - x
169+
call __CIRCLE_PLOT ; plot(x0 - x, y0 - y)
170+
171+
ld a, d
172+
add a, l
173+
ld b, a ; B = y0 + x
174+
ld a, e
175+
add a, h
176+
ld c, a ; C = x0 + y
177+
call __CIRCLE_PLOT ; plot(x0 + y, y0 + x)
178+
179+
ld a, d
180+
add a, l
181+
ld b, a ; B = y0 + x
182+
ld a, e
183+
sub h
184+
ld c, a ; C = x0 - y
185+
call __CIRCLE_PLOT ; plot(x0 - y, y0 + x)
186+
187+
ld a, d
188+
sub l
189+
ld b, a ; B = y0 - x
190+
ld a, e
191+
add a, h
192+
ld c, a ; C = x0 + y
193+
call __CIRCLE_PLOT ; plot(x0 + y, y0 - x)
194+
195+
ld a, d
196+
sub l
197+
ld b, a ; B = y0 - x
198+
ld a, e
199+
sub h
200+
ld c, a ; C = x0 + y
201+
call __CIRCLE_PLOT ; plot(x0 - y, y0 - x)
202+
203+
exx
204+
jp __CIRCLE_LOOP
201205

202206

203207

204208
__CIRCLE_PLOT:
205-
; Plots a point of the circle, preserving HL and DE
206-
push hl
207-
push de
208-
call __PLOT
209-
pop de
210-
pop hl
211-
ret
212-
213-
ENDP
209+
; Plots a point of the circle, preserving HL and DE
210+
push hl
211+
push de
212+
call __PLOT
213+
pop de
214+
pop hl
215+
ret
216+
217+
ENDP

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