intravenous

annotate src/vein.cc @ 4:c6a6a64df6de

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author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 22 Apr 2012 05:20:03 +0300
parents 94d4c60af435
children aab0d8ea21cd
rev   line source
nuclear@3 1 #include <stdio.h>
nuclear@1 2 #ifndef _MSC_VER
nuclear@1 3 #include <alloca.h>
nuclear@1 4 #else
nuclear@1 5 #include <malloc.h>
nuclear@1 6 #endif
nuclear@1 7 #include "vein.h"
nuclear@1 8 #include "geom.h"
nuclear@3 9 #include "sdr.h"
nuclear@4 10 #include "tex.h"
nuclear@1 11
nuclear@1 12 Vein::Vein()
nuclear@1 13 {
nuclear@3 14 gen_dist = 16.0;
nuclear@4 15 subdiv = 32;
nuclear@4 16 ring_subdiv = 24;
nuclear@4 17 rad = 2.0;
nuclear@1 18
nuclear@1 19 idxbuf = 0;
nuclear@4 20
nuclear@4 21 sdr = tex_norm = 0;
nuclear@1 22 }
nuclear@1 23
nuclear@1 24 Vein::~Vein()
nuclear@1 25 {
nuclear@1 26 delete [] idxbuf;
nuclear@4 27
nuclear@4 28 free_texture(tex_norm);
nuclear@4 29 free_program(sdr);
nuclear@1 30 }
nuclear@1 31
nuclear@1 32 Vector3 Vein::calc_center(const Vector3 &ppos) const
nuclear@1 33 {
nuclear@3 34 Vector3 pt{0, 0, ppos.z};
nuclear@3 35 pt.x = sin(ppos.z * 0.75);
nuclear@3 36 pt.y = cos(ppos.z * 0.2) * 0.6;
nuclear@3 37 return pt;
nuclear@1 38 }
nuclear@1 39
nuclear@1 40 Vector3 Vein::calc_dir(const Vector3 &ppos) const
nuclear@1 41 {
nuclear@3 42 Vector3 dir = calc_center(ppos + Vector3(0, 0, 0.01)) - calc_center(ppos - Vector3(0, 0, 0.01));
nuclear@3 43 return dir.normalized();
nuclear@1 44 }
nuclear@1 45
nuclear@1 46 void Vein::build_idxbuf()
nuclear@1 47 {
nuclear@1 48 delete [] idxbuf;
nuclear@1 49
nuclear@1 50 int nfaces = subdiv * ring_subdiv;
nuclear@1 51 int nidx = nfaces * 4;
nuclear@1 52 idxbuf = new unsigned int[nidx];
nuclear@1 53 unsigned int *idxptr = idxbuf;
nuclear@1 54
nuclear@1 55 for(int i=0; i<subdiv; i++) {
nuclear@1 56 for(int j=0; j<ring_subdiv; j++) {
nuclear@1 57 idxptr[0] = i * ring_subdiv + j;
nuclear@1 58 idxptr[1] = i * ring_subdiv + ((j + 1) % ring_subdiv);
nuclear@1 59 idxptr[2] = idxptr[1] + ring_subdiv;
nuclear@1 60 idxptr[3] = idxptr[0] + ring_subdiv;
nuclear@1 61 idxptr += 4;
nuclear@1 62 }
nuclear@1 63 }
nuclear@1 64 }
nuclear@1 65
nuclear@3 66 bool Vein::init()
nuclear@3 67 {
nuclear@3 68 if(!(sdr = create_program_load("sdr/vein.v.glsl", "sdr/vein.p.glsl"))) {
nuclear@3 69 fprintf(stderr, "failed to load vein shaders\n");
nuclear@3 70 return false;
nuclear@3 71 }
nuclear@3 72 if((attr_tang_loc = get_attrib_loc(sdr, "attr_tang")) == -1) {
nuclear@3 73 fprintf(stderr, "can't find tangent attribute!\n");
nuclear@3 74 }
nuclear@4 75 set_uniform_int(sdr, "tex_norm", 0);
nuclear@4 76
nuclear@4 77 if(!(tex_norm = load_texture("data/normal1.png"))) {
nuclear@4 78 return false;
nuclear@4 79 }
nuclear@3 80 return true;
nuclear@3 81 }
nuclear@3 82
nuclear@1 83 void Vein::draw(const Vector3 &ppos) const
nuclear@1 84 {
nuclear@1 85 float start_z = ppos.z - gen_dist / 2.0;
nuclear@1 86 float dz = gen_dist / subdiv;
nuclear@1 87
nuclear@1 88 int nslices = subdiv + 1;
nuclear@1 89 int nverts = nslices * ring_subdiv;
nuclear@1 90 int nfaces = subdiv * ring_subdiv;
nuclear@1 91 Vertex *vbuf = (Vertex*)alloca(nverts * sizeof *vbuf);
nuclear@1 92 Vertex *vptr = vbuf;
nuclear@1 93
nuclear@1 94 Vector3 pt = ppos;
nuclear@1 95 pt.z = start_z;
nuclear@1 96
nuclear@1 97 for(int i=0; i<nslices; i++) {
nuclear@1 98 Vector3 cent = calc_center(pt);
nuclear@1 99 Vector3 dir = calc_dir(pt);
nuclear@1 100 Vector3 up(0, 1, 0);
nuclear@1 101 Vector3 right = cross_product(up, dir);
nuclear@1 102 up = cross_product(dir, right);
nuclear@1 103
nuclear@1 104 Matrix3x3 vrot{right, up, dir};
nuclear@3 105 vrot.transpose();
nuclear@1 106
nuclear@4 107 float theta = 0.0, dtheta = 2.0 * M_PI / (ring_subdiv - 1);
nuclear@1 108 for(int j=0; j<ring_subdiv; j++) {
nuclear@3 109 Vector3 vec = Vector3{-cos(theta) * rad, sin(theta) * rad, 0.0};
nuclear@1 110 vec.transform(vrot);
nuclear@3 111 vec += cent;
nuclear@1 112
nuclear@1 113 vptr->pos = vec;
nuclear@1 114 vptr->norm = cent - vec;
nuclear@3 115 vptr->tang = dir;
nuclear@4 116 vptr->tc = Vector2(start_z + gen_dist * i / nslices, theta / (2.0 * M_PI));
nuclear@1 117 vptr++;
nuclear@1 118
nuclear@1 119 theta += dtheta;
nuclear@1 120 }
nuclear@1 121
nuclear@1 122 pt.z += dz;
nuclear@1 123 }
nuclear@1 124
nuclear@1 125 // also create the index buffer if it's not valid
nuclear@1 126 if(!idxbuf) {
nuclear@1 127 ((Vein*)this)->build_idxbuf();
nuclear@1 128 }
nuclear@1 129
nuclear@1 130 // awesome, now draw it
nuclear@4 131 glMatrixMode(GL_TEXTURE);
nuclear@4 132 glPushMatrix();
nuclear@4 133 glScalef(0.125, 1.0, 1.0);
nuclear@4 134
nuclear@4 135 bind_texture(tex_norm);
nuclear@3 136 bind_program(sdr);
nuclear@3 137 draw_mesh(GL_QUADS, nfaces * 4, vbuf, idxbuf, attr_tang_loc);
nuclear@3 138 bind_program(0);
nuclear@4 139 bind_texture(0);
nuclear@4 140
nuclear@4 141 glPopMatrix();
nuclear@1 142 }