help with trig(?) calculation
- To: mathgroup at smc.vnet.net
- Subject: [mg13155] help with trig(?) calculation
- From: Leon.Bryant at usaa.com (Leon Bryant)
- Date: Mon, 13 Jul 1998 07:42:06 -0400
- Organization: The Math Forum
- Sender: owner-wri-mathgroup at wolfram.com
i need some help from the "gurus". i am a multimedia programmer working in San Antonio, and need help with a programming idea that involves some simple(?) trig. the problem: i have a display area (computer screen) that has the dimensions 640 by 480 units (pixels). my program sets the dimensions of this rectangle to: TL - 0,0 TR - 640,0 BL - 0,480 BR - 640,480 what i would like to do is give the coordinates of a point on the screen, an angle (or a second point), and devise an algorithm that will plot where the imaginary line would inintersect the boundaries of the display area. for instance: point: (320,240) (centered on screen) angle: 45 degrees intersection point: (640,0) this one's intuitive since the starting point is centered on the screen, and the angle is 25% of 360 degrees, but i'm stumped with anything more irregular. can you explain how i'd do this? can it be put into a simple formual? email: leon.bryant at usaa.com