1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/mglgen.c	Mon Nov 21 06:14:01 2011 +0200
     1.3 @@ -0,0 +1,167 @@
     1.4 +/*
     1.5 +256-color 3D graphics hack for real-mode DOS.
     1.6 +Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
     1.7 +
     1.8 +This program is free software: you can redistribute it and/or modify
     1.9 +it under the terms of the GNU General Public License as published by
    1.10 +the Free Software Foundation, either version 3 of the License, or
    1.11 +(at your option) any later version.
    1.12 +
    1.13 +This program is distributed in the hope that it will be useful,
    1.14 +but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.15 +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.16 +GNU General Public License for more details.
    1.17 +
    1.18 +You should have received a copy of the GNU General Public License
    1.19 +along with this program.  If not, see <http://www.gnu.org/licenses/>.
    1.20 +*/
    1.21 +#include <math.h>
    1.22 +#include <assert.h>
    1.23 +#include "mingl.h"
    1.24 +
    1.25 +
    1.26 +void mgl_cube(float sz)
    1.27 +{
    1.28 +	float hsz = sz * 0.5;
    1.29 +
    1.30 +	mgl_begin(MGL_QUADS);
    1.31 +	/* front */
    1.32 +	mgl_normal(0, 0, 1);
    1.33 +	mgl_vertex3f(-hsz, hsz, hsz);
    1.34 +	mgl_vertex3f(-hsz, -hsz, hsz);
    1.35 +	mgl_vertex3f(hsz, -hsz, hsz);
    1.36 +	mgl_vertex3f(hsz, hsz, hsz);
    1.37 +	/* back */
    1.38 +	mgl_normal(0, 0, -1);
    1.39 +	mgl_vertex3f(hsz, hsz, -hsz);
    1.40 +	mgl_vertex3f(hsz, -hsz, -hsz);
    1.41 +	mgl_vertex3f(-hsz, -hsz, -hsz);
    1.42 +	mgl_vertex3f(-hsz, hsz, -hsz);
    1.43 +	/* right */
    1.44 +	mgl_normal(1, 0, 0);
    1.45 +	mgl_vertex3f(hsz, hsz, hsz);
    1.46 +	mgl_vertex3f(hsz, -hsz, hsz);
    1.47 +	mgl_vertex3f(hsz, -hsz, -hsz);
    1.48 +	mgl_vertex3f(hsz, hsz, -hsz);
    1.49 +	/* left */
    1.50 +	mgl_normal(-1, 0, 0);
    1.51 +	mgl_vertex3f(-hsz, hsz, -hsz);
    1.52 +	mgl_vertex3f(-hsz, -hsz, -hsz);
    1.53 +	mgl_vertex3f(-hsz, -hsz, hsz);
    1.54 +	mgl_vertex3f(-hsz, hsz, hsz);
    1.55 +	/* top */
    1.56 +	mgl_normal(0, 1, 0);
    1.57 +	mgl_vertex3f(-hsz, hsz, -hsz);
    1.58 +	mgl_vertex3f(-hsz, hsz, hsz);
    1.59 +	mgl_vertex3f(hsz, hsz, hsz);
    1.60 +	mgl_vertex3f(hsz, hsz, -hsz);
    1.61 +	/* bottom */
    1.62 +	mgl_normal(0, -1, 0);
    1.63 +	mgl_vertex3f(hsz, -hsz, -hsz);
    1.64 +	mgl_vertex3f(hsz, -hsz, hsz);
    1.65 +	mgl_vertex3f(-hsz, -hsz, hsz);
    1.66 +	mgl_vertex3f(-hsz, -hsz, -hsz);
    1.67 +	mgl_end();
    1.68 +}
    1.69 +
    1.70 +void mgl_sphere(float rad, int usub, int vsub)
    1.71 +{
    1.72 +	mgl_sphere_part(rad, usub, vsub, 1.0, 1.0);
    1.73 +}
    1.74 +
    1.75 +#define sphere_vertex(u, v) \
    1.76 +	do { \
    1.77 +		float x, y, z, theta, phi; \
    1.78 +		float costheta, sinphi; \
    1.79 +		theta = (u) * 2.0 * M_PI; \
    1.80 +		phi = (v) * M_PI; \
    1.81 +		costheta = cos(theta); \
    1.82 +		sinphi = sin(phi); \
    1.83 +		x = costheta * sinphi; \
    1.84 +		y = cos(phi); \
    1.85 +		z = sin(theta) * sinphi; \
    1.86 +		mgl_normal(x, y, z); \
    1.87 +		mgl_texcoord2f(u, v); \
    1.88 +		mgl_vertex3f(rad * x, rad * y, rad * z); \
    1.89 +	} while(0)
    1.90 +
    1.91 +void mgl_sphere_part(float rad, int usub, int vsub, float umax, float vmax)
    1.92 +{
    1.93 +	int i, j;
    1.94 +	float u, v, du, dv;
    1.95 +
    1.96 +	assert(usub > 2);
    1.97 +	assert(vsub > 2);
    1.98 +
    1.99 +	du = umax / (float)usub;
   1.100 +	dv = vmax / (float)vsub;
   1.101 +
   1.102 +	mgl_begin(MGL_QUADS);
   1.103 +
   1.104 +	u = 0.0;
   1.105 +	for(i=0; i<usub; i++) {
   1.106 +		v = 0.0;
   1.107 +		for(j=0; j<vsub; j++) {
   1.108 +			sphere_vertex(u, v);
   1.109 +			sphere_vertex(u + du, v);
   1.110 +			sphere_vertex(u + du, v + dv);
   1.111 +			sphere_vertex(u, v + dv);
   1.112 +			v += dv;
   1.113 +		}
   1.114 +		u += du;
   1.115 +	}
   1.116 +	mgl_end();
   1.117 +}
   1.118 +
   1.119 +void mgl_torus(float inner, float outer, int usub, int vsub)
   1.120 +{
   1.121 +	mgl_torus_part(inner, outer, usub, vsub, 1.0, 0.0, 1.0);
   1.122 +}
   1.123 +
   1.124 +#define torus_vertex(u, v) \
   1.125 +	do { \
   1.126 +		float rx, ry, rz, cx, cy, cz, theta, phi; \
   1.127 +		float costheta, sintheta, sinphi; \
   1.128 +		theta = (u) * 2.0 * M_PI; \
   1.129 +		phi = (v) * 2.0 * M_PI; \
   1.130 +		costheta = cos(theta); \
   1.131 +		sintheta = sin(theta); \
   1.132 +		sinphi = sin(phi); \
   1.133 +		cx = costheta * inner; \
   1.134 +		cy = 0.0f; \
   1.135 +		cz = sintheta * inner; \
   1.136 +		rx = costheta * sinphi; \
   1.137 +		ry = cos(phi); \
   1.138 +		rz = sintheta * sinphi; \
   1.139 +		mgl_normal(rx, ry, rz); \
   1.140 +		mgl_texcoord2f(u, v); \
   1.141 +		mgl_vertex3f(outer * rx + cx, outer * ry + cy, outer * rz + cz); \
   1.142 +	} while(0)
   1.143 +
   1.144 +void mgl_torus_part(float inner, float outer, int usub, int vsub, float umax, float vmin, float vmax)
   1.145 +{
   1.146 +	int i, j;
   1.147 +	float u, v, du, dv;
   1.148 +
   1.149 +	assert(usub > 2);
   1.150 +	assert(vsub > 2);
   1.151 +
   1.152 +	du = umax / (float)usub;
   1.153 +	dv = (vmax - vmin) / (float)vsub;
   1.154 +
   1.155 +	mgl_begin(MGL_QUADS);
   1.156 +
   1.157 +	u = 0.0;
   1.158 +	for(i=0; i<usub; i++) {
   1.159 +		v = vmin;
   1.160 +		for(j=0; j<vsub; j++) {
   1.161 +			torus_vertex(u, v);
   1.162 +			torus_vertex(u + du, v);
   1.163 +			torus_vertex(u + du, v + dv);
   1.164 +			torus_vertex(u, v + dv);
   1.165 +			v += dv;
   1.166 +		}
   1.167 +		u += du;
   1.168 +	}
   1.169 +	mgl_end();
   1.170 +}