dos3d

annotate src/mglgen.c @ 12:c29a6e024950

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merged
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 28 Nov 2011 05:03:22 +0200
parents 0e781cc43178
children 00d84ab1ef26
rev   line source
nuclear@0 1 /*
nuclear@0 2 256-color 3D graphics hack for real-mode DOS.
nuclear@0 3 Copyright (C) 2011 John Tsiombikas <nuclear@member.fsf.org>
nuclear@0 4
nuclear@0 5 This program is free software: you can redistribute it and/or modify
nuclear@0 6 it under the terms of the GNU General Public License as published by
nuclear@0 7 the Free Software Foundation, either version 3 of the License, or
nuclear@0 8 (at your option) any later version.
nuclear@0 9
nuclear@0 10 This program is distributed in the hope that it will be useful,
nuclear@0 11 but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@0 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
nuclear@0 13 GNU General Public License for more details.
nuclear@0 14
nuclear@0 15 You should have received a copy of the GNU General Public License
nuclear@0 16 along with this program. If not, see <http://www.gnu.org/licenses/>.
nuclear@0 17 */
nuclear@0 18 #include <math.h>
nuclear@0 19 #include <assert.h>
nuclear@0 20 #include "mingl.h"
nuclear@0 21
nuclear@0 22
nuclear@0 23 void mgl_cube(float sz)
nuclear@0 24 {
nuclear@0 25 float hsz = sz * 0.5;
nuclear@0 26
nuclear@0 27 mgl_begin(MGL_QUADS);
nuclear@0 28 /* front */
nuclear@0 29 mgl_normal(0, 0, 1);
nuclear@9 30 mgl_texcoord2f(0, 0); mgl_vertex3f(-hsz, hsz, hsz);
nuclear@9 31 mgl_texcoord2f(0, 1); mgl_vertex3f(-hsz, -hsz, hsz);
nuclear@9 32 mgl_texcoord2f(1, 1); mgl_vertex3f(hsz, -hsz, hsz);
nuclear@9 33 mgl_texcoord2f(1, 0); mgl_vertex3f(hsz, hsz, hsz);
nuclear@0 34 /* back */
nuclear@0 35 mgl_normal(0, 0, -1);
nuclear@9 36 mgl_texcoord2f(0, 0); mgl_vertex3f(hsz, hsz, -hsz);
nuclear@9 37 mgl_texcoord2f(0, 1); mgl_vertex3f(hsz, -hsz, -hsz);
nuclear@9 38 mgl_texcoord2f(1, 1); mgl_vertex3f(-hsz, -hsz, -hsz);
nuclear@9 39 mgl_texcoord2f(1, 0); mgl_vertex3f(-hsz, hsz, -hsz);
nuclear@0 40 /* right */
nuclear@0 41 mgl_normal(1, 0, 0);
nuclear@9 42 mgl_texcoord2f(0, 0); mgl_vertex3f(hsz, hsz, hsz);
nuclear@9 43 mgl_texcoord2f(0, 1); mgl_vertex3f(hsz, -hsz, hsz);
nuclear@9 44 mgl_texcoord2f(1, 1); mgl_vertex3f(hsz, -hsz, -hsz);
nuclear@9 45 mgl_texcoord2f(1, 0); mgl_vertex3f(hsz, hsz, -hsz);
nuclear@0 46 /* left */
nuclear@0 47 mgl_normal(-1, 0, 0);
nuclear@9 48 mgl_texcoord2f(0, 0); mgl_vertex3f(-hsz, hsz, -hsz);
nuclear@9 49 mgl_texcoord2f(0, 1); mgl_vertex3f(-hsz, -hsz, -hsz);
nuclear@9 50 mgl_texcoord2f(1, 1); mgl_vertex3f(-hsz, -hsz, hsz);
nuclear@9 51 mgl_texcoord2f(1, 0); mgl_vertex3f(-hsz, hsz, hsz);
nuclear@0 52 /* top */
nuclear@0 53 mgl_normal(0, 1, 0);
nuclear@9 54 mgl_texcoord2f(0, 0); mgl_vertex3f(-hsz, hsz, -hsz);
nuclear@9 55 mgl_texcoord2f(0, 1); mgl_vertex3f(-hsz, hsz, hsz);
nuclear@9 56 mgl_texcoord2f(1, 1); mgl_vertex3f(hsz, hsz, hsz);
nuclear@9 57 mgl_texcoord2f(1, 0); mgl_vertex3f(hsz, hsz, -hsz);
nuclear@0 58 /* bottom */
nuclear@0 59 mgl_normal(0, -1, 0);
nuclear@9 60 mgl_texcoord2f(0, 0); mgl_vertex3f(hsz, -hsz, -hsz);
nuclear@9 61 mgl_texcoord2f(0, 1); mgl_vertex3f(hsz, -hsz, hsz);
nuclear@9 62 mgl_texcoord2f(1, 1); mgl_vertex3f(-hsz, -hsz, hsz);
nuclear@9 63 mgl_texcoord2f(1, 0); mgl_vertex3f(-hsz, -hsz, -hsz);
nuclear@0 64 mgl_end();
nuclear@0 65 }
nuclear@0 66
nuclear@0 67 void mgl_sphere(float rad, int usub, int vsub)
nuclear@0 68 {
nuclear@0 69 mgl_sphere_part(rad, usub, vsub, 1.0, 1.0);
nuclear@0 70 }
nuclear@0 71
nuclear@0 72 #define sphere_vertex(u, v) \
nuclear@0 73 do { \
nuclear@0 74 float x, y, z, theta, phi; \
nuclear@0 75 float costheta, sinphi; \
nuclear@0 76 theta = (u) * 2.0 * M_PI; \
nuclear@0 77 phi = (v) * M_PI; \
nuclear@0 78 costheta = cos(theta); \
nuclear@0 79 sinphi = sin(phi); \
nuclear@0 80 x = costheta * sinphi; \
nuclear@0 81 y = cos(phi); \
nuclear@0 82 z = sin(theta) * sinphi; \
nuclear@0 83 mgl_normal(x, y, z); \
nuclear@0 84 mgl_texcoord2f(u, v); \
nuclear@0 85 mgl_vertex3f(rad * x, rad * y, rad * z); \
nuclear@0 86 } while(0)
nuclear@0 87
nuclear@0 88 void mgl_sphere_part(float rad, int usub, int vsub, float umax, float vmax)
nuclear@0 89 {
nuclear@0 90 int i, j;
nuclear@0 91 float u, v, du, dv;
nuclear@0 92
nuclear@0 93 assert(usub > 2);
nuclear@0 94 assert(vsub > 2);
nuclear@0 95
nuclear@0 96 du = umax / (float)usub;
nuclear@0 97 dv = vmax / (float)vsub;
nuclear@0 98
nuclear@0 99 mgl_begin(MGL_QUADS);
nuclear@0 100
nuclear@0 101 u = 0.0;
nuclear@0 102 for(i=0; i<usub; i++) {
nuclear@0 103 v = 0.0;
nuclear@0 104 for(j=0; j<vsub; j++) {
nuclear@0 105 sphere_vertex(u, v);
nuclear@0 106 sphere_vertex(u + du, v);
nuclear@0 107 sphere_vertex(u + du, v + dv);
nuclear@0 108 sphere_vertex(u, v + dv);
nuclear@0 109 v += dv;
nuclear@0 110 }
nuclear@0 111 u += du;
nuclear@0 112 }
nuclear@0 113 mgl_end();
nuclear@0 114 }
nuclear@0 115
nuclear@0 116 void mgl_torus(float inner, float outer, int usub, int vsub)
nuclear@0 117 {
nuclear@0 118 mgl_torus_part(inner, outer, usub, vsub, 1.0, 0.0, 1.0);
nuclear@0 119 }
nuclear@0 120
nuclear@0 121 #define torus_vertex(u, v) \
nuclear@0 122 do { \
nuclear@0 123 float rx, ry, rz, cx, cy, cz, theta, phi; \
nuclear@0 124 float costheta, sintheta, sinphi; \
nuclear@0 125 theta = (u) * 2.0 * M_PI; \
nuclear@0 126 phi = (v) * 2.0 * M_PI; \
nuclear@0 127 costheta = cos(theta); \
nuclear@0 128 sintheta = sin(theta); \
nuclear@0 129 sinphi = sin(phi); \
nuclear@0 130 cx = costheta * inner; \
nuclear@0 131 cy = 0.0f; \
nuclear@0 132 cz = sintheta * inner; \
nuclear@0 133 rx = costheta * sinphi; \
nuclear@0 134 ry = cos(phi); \
nuclear@0 135 rz = sintheta * sinphi; \
nuclear@0 136 mgl_normal(rx, ry, rz); \
nuclear@0 137 mgl_texcoord2f(u, v); \
nuclear@0 138 mgl_vertex3f(outer * rx + cx, outer * ry + cy, outer * rz + cz); \
nuclear@0 139 } while(0)
nuclear@0 140
nuclear@0 141 void mgl_torus_part(float inner, float outer, int usub, int vsub, float umax, float vmin, float vmax)
nuclear@0 142 {
nuclear@0 143 int i, j;
nuclear@0 144 float u, v, du, dv;
nuclear@0 145
nuclear@0 146 assert(usub > 2);
nuclear@0 147 assert(vsub > 2);
nuclear@0 148
nuclear@0 149 du = umax / (float)usub;
nuclear@0 150 dv = (vmax - vmin) / (float)vsub;
nuclear@0 151
nuclear@0 152 mgl_begin(MGL_QUADS);
nuclear@0 153
nuclear@0 154 u = 0.0;
nuclear@0 155 for(i=0; i<usub; i++) {
nuclear@0 156 v = vmin;
nuclear@0 157 for(j=0; j<vsub; j++) {
nuclear@0 158 torus_vertex(u, v);
nuclear@0 159 torus_vertex(u + du, v);
nuclear@0 160 torus_vertex(u + du, v + dv);
nuclear@0 161 torus_vertex(u, v + dv);
nuclear@0 162 v += dv;
nuclear@0 163 }
nuclear@0 164 u += du;
nuclear@0 165 }
nuclear@0 166 mgl_end();
nuclear@0 167 }