glviewvol

annotate src/rend_fast.cc @ 1:cc9e0d8590e2

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author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 27 Dec 2014 06:32:28 +0200
parents
children 04330eb80b36
rev   line source
nuclear@0 1 #include "opengl.h"
nuclear@0 2 #include "rend_fast.h"
nuclear@0 3
nuclear@0 4 RendererFast::RendererFast()
nuclear@0 5 {
nuclear@0 6 vol_tex = 0;
nuclear@0 7 vol_tex_valid = false;
nuclear@0 8 }
nuclear@0 9
nuclear@0 10 bool RendererFast::init()
nuclear@0 11 {
nuclear@0 12 glGenTextures(1, &vol_tex);
nuclear@0 13 glBindTexture(GL_TEXTURE_3D, vol_tex);
nuclear@0 14 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@0 15 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@0 16
nuclear@0 17 return true;
nuclear@0 18 }
nuclear@0 19
nuclear@0 20 void RendererFast::destroy()
nuclear@0 21 {
nuclear@0 22 glDeleteTextures(1, &vol_tex);
nuclear@0 23 }
nuclear@0 24
nuclear@0 25 void RendererFast::update(unsigned int msec)
nuclear@0 26 {
nuclear@0 27 if(!vol) return;
nuclear@0 28
nuclear@0 29 // make sure the 3D volume texture is up to date
nuclear@0 30 if(!vol_tex_valid) {
nuclear@0 31 int xsz, ysz, zsz;
nuclear@0 32
nuclear@0 33 if((xsz = vol->num_samples(0)) > 0) {
nuclear@0 34 ysz = vol->num_samples(1);
nuclear@0 35 zsz = vol->num_samples(2);
nuclear@0 36 } else {
nuclear@0 37 xsz = ysz = zsz = 256;
nuclear@0 38 }
nuclear@0 39
nuclear@0 40 int int_fmt = GLEW_ARB_texture_float ? GL_RGBA16F_ARB : GL_RGBA;
nuclear@0 41
nuclear@0 42 glBindTexture(GL_TEXTURE_3D, vol_tex);
nuclear@0 43 glTexImage3D(GL_TEXTURE_3D, 0, int_fmt, xsz, ysz, zsz, 0, GL_RGBA, GL_FLOAT, 0);
nuclear@0 44
nuclear@0 45 float *slice = new float[xsz * ysz * 4];
nuclear@0 46
nuclear@0 47 for(int i=0; i<zsz; i++) {
nuclear@0 48 float z = (float)i / (float)(zsz - 1);
nuclear@0 49 float *pptr = slice;
nuclear@0 50
nuclear@0 51 for(int j=0; j<ysz; j++) {
nuclear@0 52 float y = (float)j / (float)(ysz - 1);
nuclear@0 53 for(int k=0; k<xsz; k++) {
nuclear@0 54 float x = (float)k / (float)(xsz - 1);
nuclear@0 55
nuclear@0 56 // value in alpha channel
nuclear@0 57 pptr[3] = vol->valuef(x, y, z);
nuclear@0 58 // normal in rgb
nuclear@0 59 vol->normalf(pptr, x, y, z);
nuclear@0 60 // shift normal to the [0,1] range in case we don't have tex_float
nuclear@0 61 pptr[0] = pptr[0] * 0.5 + 0.5;
nuclear@0 62 pptr[1] = pptr[1] * 0.5 + 0.5;
nuclear@0 63 pptr[2] = pptr[2] * 0.5 + 0.5;
nuclear@0 64 }
nuclear@0 65 }
nuclear@0 66
nuclear@0 67 glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, i, xsz, ysz, 1, GL_RGBA, GL_FLOAT, slice);
nuclear@0 68 }
nuclear@0 69
nuclear@0 70 delete [] slice;
nuclear@0 71
nuclear@0 72 vol_tex_valid = true;
nuclear@0 73 }
nuclear@0 74 }
nuclear@0 75
nuclear@0 76 void RendererFast::render() const
nuclear@0 77 {
nuclear@0 78 if(!vol) return;
nuclear@0 79
nuclear@0 80 glClear(GL_COLOR_BUFFER_BIT);
nuclear@0 81
nuclear@0 82 glMatrixMode(GL_PROJECTION);
nuclear@0 83 glPushMatrix();
nuclear@0 84 glLoadIdentity();
nuclear@0 85
nuclear@0 86 glMatrixMode(GL_MODELVIEW);
nuclear@0 87 glPushMatrix();
nuclear@0 88 glLoadIdentity();
nuclear@0 89
nuclear@0 90 glBindTexture(GL_TEXTURE_3D, vol_tex);
nuclear@0 91 glBegin(GL_QUADS);
nuclear@0 92 glTexCoord3f(0, 0, 0); glVertex2f(-1, -1);
nuclear@0 93 glTexCoord3f(1, 0, 0); glVertex2f(1, -1);
nuclear@0 94 glTexCoord3f(1, 1, 0); glVertex2f(1, 1);
nuclear@0 95 glTexCoord3f(0, 1, 0); glVertex2f(-1, 1);
nuclear@0 96 glEnd();
nuclear@0 97
nuclear@0 98 glMatrixMode(GL_PROJECTION);
nuclear@0 99 glPopMatrix();
nuclear@0 100 glMatrixMode(GL_MODELVIEW);
nuclear@0 101 glPopMatrix();
nuclear@0 102 }