EGFX · FUNCTION 26ALPHA · USE AT YOUR OWN RISK
BEZIER
Draw a Bézier curve.
Uses quadratic or cubic control points and bounded integer subdivision.
Parameters
| Name | Order | Description |
|---|---|---|
DEGREE | 8 | 2 or 3. |
STEPS | 9 | 1–32 subdivisions. |
COLOUR | 10 | Logical colour. |
CONTROLS | 16–63 | Signed control points. |
BASIC example
Tested listing: curves-demo.bas.
10 MODE 1:HIMEM=&2400:PROCeginit
20 REPEAT:PROCegbegin
30 PROCegarc(64,96,32,200,56,1,2):PROCegarc(176,96,32,0,192,0,3)
40 v$=FNegvertex(16,192)+FNegvertex(128,112)+FNegvertex(288,192)
50 PROCegbezier(v$,16,3)
60 v$=FNegvertex(16,216)+FNegvertex(96,128)+FNegvertex(224,216)+FNegvertex(288,160)
70 PROCegbezier(v$,24,1)
80 PROCegtext("ARCS AND BEZIERS",8,8)
90 PROCegpresent:UNTIL INKEY(0)=81
100 END
Assembly example
JSR init_egfx
JSR begin_frame
LDA #26 : JSR eg_call
JSR present_frame
RTS