cal/cal/screen.cal

{
        Uses gensurf to compute CRT geometry based on spherical assumption.

        Author:
                Greg Ward       11/13/95

        Input:
                w:      screen width (total)
                h:      screen height (total)
                d:      displacement from center tangent at max. right or left

        Usage:
                gensurf mat name 'x(s,t)' 'y(s,t)' 'z(s,t)' N M -s \
                        -e 'w:{width};h:{height};d:{depth}' -f screen.cal

        Output is oriented vertically, with the lower left corner at
        (x,y,z)=(0,0,0), the lower right at (w,0,0), the upper right
        at (w,0,h), and the screen bulge in the negative y direction.
        Surface normals face negative y, also.
}
                                { compute sphere radius }
r : d/2 + w*w/8/d;
                                { compute x and z }
x(s,t) = w*s;
z(s,t) = h*t;

sq(x) : x*x;
                                { compute maximum depth (y) value }
dmax : sqrt(r*r - sq(w/2) - sq(h/2));
                                { compute y }
y(s,t) = dmax - sqrt(r*r - sq(w*s-w/2) - sq(h*t-h/2));
Revision:	1.1
Committed:	Sat Feb 22 02:07:21 2003 UTC (21 years, 2 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R2, rad4R2P2, rad5R0, rad5R1, rad3R7P2, rad3R7P1, rad4R2, rad4R1, rad4R0, rad3R5, rad3R6, rad3R6P1, rad3R8, rad3R9, rad4R2P1
Log Message:	Changes and check-in for 3.5 release Includes new source files and modifications not recorded for many years See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release
#	User	Rev	Content
1	greg	1.1	{
2			Uses gensurf to compute CRT geometry based on spherical assumption.
3
4			Author:
5			Greg Ward 11/13/95
6
7			Input:
8			w: screen width (total)
9			h: screen height (total)
10			d: displacement from center tangent at max. right or left
11
12			Usage:
13			gensurf mat name 'x(s,t)' 'y(s,t)' 'z(s,t)' N M -s \
14			-e 'w:{width};h:{height};d:{depth}' -f screen.cal
15
16			Output is oriented vertically, with the lower left corner at
17			(x,y,z)=(0,0,0), the lower right at (w,0,0), the upper right
18			at (w,0,h), and the screen bulge in the negative y direction.
19			Surface normals face negative y, also.
20			}
21			{ compute sphere radius }
22			r : d/2 + w*w/8/d;
23			{ compute x and z }
24			x(s,t) = w*s;
25			z(s,t) = h*t;
26
27			sq(x) : x*x;
28			{ compute maximum depth (y) value }
29			dmax : sqrt(r*r - sq(w/2) - sq(h/2));
30			{ compute y }
31			y(s,t) = dmax - sqrt(rr - sq(ws-w/2) - sq(h*t-h/2));