CompuServe Messages

#Stretching Turbo C

    19-Jan-90 19:12:46
Sb: #Stretching Turbo C
Fm: – Visitor 71601,170
To: kent porter 76704,51
Kent – I bought your book 'Stretching Turbo C' primarily to get the Bezier curve subroutine. I am having a problem ! Sometimes the gravity effect is centered around the 0,0 coord. pts. . This problem only seems to occur using larger point sets (six +). 1. Are there limitations on the points enter into these functions. If so what are they. 2. If not, do you have any idea on what might cause the Bezier function to drift towards the 0,0 pt. When I say drift I really mean the curve starts at the beg pt. then it goes directly to the 0,0 and from there to the end pt. Sometimes is does a small loop near the 0,0 pt. before finishing up. I am using a Atari 520 upgraded to 1 meg. The only change I have made to your code is the function lineto(), which I have changed to put_pixel() (sets screen bits to plot points on screen). I have checked the set of points going in and they were correct. The points coming out of the function, however reflect the problem. Any ideas on this problem are appreciated. Aaron