factor/extra/jamshred/gl/gl.factor

114 lines
3.6 KiB
Factor

! Copyright (C) 2007, 2008 Alex Chapman
! See http://factorcode.org/license.txt for BSD license.
USING: accessors alien.c-types jamshred.game jamshred.tunnel
kernel literals locals math math.constants math.functions
math.vectors opengl opengl.demo-support opengl.gl opengl.glu
sequences specialized-arrays ;
SPECIALIZED-ARRAY: alien.c-types:float
IN: jamshred.gl
CONSTANT: min-vertices 6
CONSTANT: max-vertices 32
CONSTANT: n-vertices 32
! render enough of the tunnel that it looks continuous
CONSTANT: n-segments-ahead 60
CONSTANT: n-segments-behind 40
! so that we can't see through the wall, we draw it a bit further away
CONSTANT: wall-drawing-offset 0.15
: wall-drawing-radius ( segment -- r )
radius>> wall-drawing-offset + ;
: wall-up ( segment -- v )
[ wall-drawing-radius ] [ up>> ] bi n*v ;
: wall-left ( segment -- v )
[ wall-drawing-radius ] [ left>> ] bi n*v ;
: segment-vertex ( theta segment -- vertex )
[
[ wall-up swap sin v*n ] [ wall-left swap cos v*n ] 2bi v+
] [
location>> v+
] bi ;
: segment-vertex-normal ( vertex segment -- normal )
location>> swap v- normalize ;
: segment-vertex-and-normal ( segment theta -- vertex normal )
swap [ segment-vertex ] keep dupd segment-vertex-normal ;
: equally-spaced-radians ( n -- seq )
! return a sequence of n numbers between 0 and 2pi
[ <iota> ] keep [ / pi 2 * * ] curry map ;
: draw-segment-vertex ( segment theta -- )
over color>> gl-color segment-vertex-and-normal
gl-normal gl-vertex ;
:: draw-vertex-pair ( theta next-segment segment -- )
segment theta draw-segment-vertex
next-segment theta draw-segment-vertex ;
: draw-segment ( next-segment segment -- )
GL_QUAD_STRIP [
[ draw-vertex-pair ] 2curry
n-vertices equally-spaced-radians float-array{ 0.0 } append swap each
] do-state ;
: draw-segments ( segments -- )
1 over length pick subseq swap [ draw-segment ] 2each ;
: segments-to-render ( player -- segments )
dup nearest-segment>> number>> dup n-segments-behind -
swap n-segments-ahead + rot tunnel>> sub-tunnel ;
: draw-tunnel ( player -- )
segments-to-render draw-segments ;
: init-graphics ( -- )
GL_DEPTH_TEST glEnable
GL_SCISSOR_TEST glDisable
1.0 glClearDepth
0.0 0.0 0.0 0.0 glClearColor
GL_PROJECTION glMatrixMode glPushMatrix
GL_MODELVIEW glMatrixMode glPushMatrix
GL_LEQUAL glDepthFunc
GL_LIGHTING glEnable
GL_LIGHT0 glEnable
GL_FOG glEnable
GL_FOG_DENSITY 0.09 glFogf
GL_FRONT GL_AMBIENT_AND_DIFFUSE glColorMaterial
GL_COLOR_MATERIAL glEnable
GL_LIGHT0 GL_POSITION float-array{ 0.0 0.0 0.0 1.0 } underlying>> glLightfv
GL_LIGHT0 GL_AMBIENT float-array{ 0.2 0.2 0.2 1.0 } underlying>> glLightfv
GL_LIGHT0 GL_DIFFUSE float-array{ 1.0 1.0 1.0 1.0 } underlying>> glLightfv
GL_LIGHT0 GL_SPECULAR float-array{ 1.0 1.0 1.0 1.0 } underlying>> glLightfv ;
: cleanup-graphics ( -- )
GL_DEPTH_TEST glDisable
GL_SCISSOR_TEST glEnable
GL_MODELVIEW glMatrixMode glPopMatrix
GL_PROJECTION glMatrixMode glPopMatrix
GL_LIGHTING glDisable
GL_LIGHT0 glDisable
GL_FOG glDisable
GL_COLOR_MATERIAL glDisable ;
: pre-draw ( width height -- )
flags{ GL_COLOR_BUFFER_BIT GL_DEPTH_BUFFER_BIT } glClear
GL_PROJECTION glMatrixMode glLoadIdentity
dup 0 = [ 2drop ] [ / >float 45.0 swap 0.1 100.0 gluPerspective ] if
GL_MODELVIEW glMatrixMode glLoadIdentity ;
: player-view ( player -- )
[ location>> ]
[ [ location>> ] [ forward>> ] bi v+ ]
[ up>> ] tri gl-look-at ;
: draw-jamshred ( jamshred width height -- )
pre-draw jamshred-player [ player-view ] [ draw-tunnel ] bi ;