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annotate src/teapot.c @ 14:25cab9e20c9c

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mesh vbos
author John Tsiombikas <nuclear@member.fsf.org>
date Thu, 09 Oct 2014 01:29:28 +0300
parents 316ec8250af2
children
rev   line source
nuclear@5 1 #include "opengl.h"
nuclear@3 2 #include "teapot.h"
nuclear@3 3 #include "teapot_data.h"
nuclear@3 4
nuclear@3 5 static void draw_patch(struct vec3 *bez_cp, int *index, int flip, int useg, int vseg, float scale);
nuclear@3 6
nuclear@3 7 int patch_subdivision = 6;
nuclear@3 8
nuclear@5 9 static int dlist_sub[32];
nuclear@5 10
nuclear@3 11 void bezier_teapot(float scale)
nuclear@3 12 {
nuclear@3 13 int i;
nuclear@3 14
nuclear@5 15 glMatrixMode(GL_MODELVIEW);
nuclear@5 16
nuclear@5 17 if(!dlist_sub[patch_subdivision]) {
nuclear@5 18 dlist_sub[patch_subdivision] = glGenLists(1);
nuclear@5 19 glNewList(dlist_sub[patch_subdivision], GL_COMPILE);
nuclear@5 20
nuclear@5 21 for(i=0; i<NUM_TEAPOT_PATCHES; i++) {
nuclear@5 22 float flip = teapot_part_flip[i];
nuclear@5 23 float rot = teapot_part_rot[i];
nuclear@5 24
nuclear@5 25 glPushMatrix();
nuclear@5 26 glTranslatef(0, -3.15 * 0.5, 0);
nuclear@5 27 glRotatef(rot, 0, 1, 0);
nuclear@5 28 glScalef(1, 1, flip);
nuclear@5 29 glRotatef(-90, 1, 0, 0);
nuclear@5 30
nuclear@5 31 draw_patch(teapot_verts, teapot_index + i * 16, flip < 0.0 ? 1 : 0, patch_subdivision, patch_subdivision, 1.0);
nuclear@5 32
nuclear@5 33 glPopMatrix();
nuclear@5 34 }
nuclear@5 35
nuclear@5 36 glEndList();
nuclear@5 37 }
nuclear@5 38
nuclear@3 39 scale /= 2.0;
nuclear@5 40 glPushMatrix();
nuclear@5 41 glScalef(scale, scale, scale);
nuclear@5 42 glCallList(dlist_sub[patch_subdivision]);
nuclear@5 43 glPopMatrix();
nuclear@3 44 }
nuclear@3 45
nuclear@3 46 static void draw_patch(struct vec3 *bez_cp, int *index, int flip, int useg, int vseg, float scale)
nuclear@3 47 {
nuclear@3 48 static const float uoffs[2][4] = {{0, 0, 1, 1}, {1, 1, 0, 0}};
nuclear@3 49 static const float voffs[4] = {0, 1, 1, 0};
nuclear@3 50
nuclear@3 51 int i, j, k;
nuclear@3 52 struct vec3 cp[16];
nuclear@3 53 struct vec3 pt, n;
nuclear@3 54 float u, v;
nuclear@3 55 float du = 1.0 / useg;
nuclear@3 56 float dv = 1.0 / vseg;
nuclear@3 57
nuclear@3 58 /* collect control points */
nuclear@3 59 for(i=0; i<16; i++) {
nuclear@3 60 cp[i] = bez_cp[index[i]];
nuclear@3 61 }
nuclear@3 62
nuclear@3 63 glBegin(GL_QUADS);
nuclear@3 64 glColor3f(1, 1, 1);
nuclear@3 65
nuclear@3 66 u = 0;
nuclear@3 67 for(i=0; i<useg; i++) {
nuclear@3 68 v = 0;
nuclear@3 69 for(j=0; j<vseg; j++) {
nuclear@3 70
nuclear@3 71 for(k=0; k<4; k++) {
nuclear@3 72 pt = bezier_patch(cp, u + uoffs[flip][k] * du, v + voffs[k] * dv);
nuclear@3 73
nuclear@3 74 /* top/bottom normal hack */
nuclear@3 75 if(pt.z > 3.14) {
nuclear@3 76 n.x = n.y = 0.0f;
nuclear@3 77 n.z = 1.0f;
nuclear@3 78 } else if(pt.z < 0.00001) {
nuclear@3 79 n.x = n.y = 0.0f;
nuclear@3 80 n.z = -1.0f;
nuclear@3 81 } else {
nuclear@3 82 n = bezier_patch_norm(cp, u + uoffs[flip][k] * du, v + voffs[k] * dv);
nuclear@3 83 }
nuclear@3 84
nuclear@3 85 glTexCoord2f(u, v);
nuclear@3 86 glNormal3f(n.x, n.y, n.z);
nuclear@3 87 glVertex3f(pt.x * scale, pt.y * scale, pt.z * scale);
nuclear@3 88 }
nuclear@3 89
nuclear@3 90 v += dv;
nuclear@3 91 }
nuclear@3 92 u += du;
nuclear@3 93 }
nuclear@3 94
nuclear@3 95 glEnd();
nuclear@3 96 }