glviewvol

view src/rend_fast.cc @ 4:04330eb80b36

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lots of stuff
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 29 Dec 2014 05:41:36 +0200
parents 7bdf40403b9c
children 5417c25cb238
line source
1 #include <stdio.h>
2 #include "opengl.h"
3 #include "rend_fast.h"
4 #include "sdr.h"
5
6 #define XFER_MAP_SZ 1024
7
8 static unsigned int sdr;
9 static bool have_tex_float;
10
11 RendererFast::RendererFast()
12 {
13 vol_tex = xfer_tex = 0;
14 vol_tex_valid = xfer_tex_valid = false;
15 }
16
17 bool RendererFast::init()
18 {
19 if(!sdr) {
20 if(!(sdr = create_program_load("sdr/fast.v.glsl", "sdr/fast.p.glsl"))) {
21 return false;
22 }
23 have_tex_float = GLEW_ARB_texture_float;
24 }
25
26 glGenTextures(1, &vol_tex);
27 glBindTexture(GL_TEXTURE_3D, vol_tex);
28 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
29 glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
30
31 glGenTextures(1, &xfer_tex);
32 glBindTexture(GL_TEXTURE_1D, xfer_tex);
33 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
34 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
35 glTexImage1D(GL_TEXTURE_1D, 0, have_tex_float ? GL_RGB16F : GL_RGB, XFER_MAP_SZ, 0, GL_RGB, GL_FLOAT, 0);
36
37 return true;
38 }
39
40 void RendererFast::destroy()
41 {
42 glDeleteTextures(1, &vol_tex);
43 glDeleteTextures(1, &xfer_tex);
44 }
45
46 void RendererFast::set_volume(Volume *vol)
47 {
48 vol_tex_valid = false;
49 Renderer::set_volume(vol);
50 }
51
52 Curve &RendererFast::transfer_curve(int color)
53 {
54 xfer_tex_valid = false;
55 return Renderer::transfer_curve(color);
56 }
57
58 void RendererFast::update(unsigned int msec)
59 {
60 if(!vol) return;
61
62 // make sure the 3D volume texture is up to date
63 if(!vol_tex_valid) {
64 int xsz, ysz, zsz;
65
66 if((xsz = vol->num_samples(0)) > 0) {
67 ysz = vol->num_samples(1);
68 zsz = vol->num_samples(2);
69 } else {
70 xsz = ysz = zsz = 256;
71 }
72
73 printf("updating 3D texture data (%dx%dx%d) ... ", xsz, ysz, zsz);
74 fflush(stdout);
75
76 int int_fmt = GLEW_ARB_texture_float ? GL_RGBA16F_ARB : GL_RGBA;
77
78 glBindTexture(GL_TEXTURE_3D, vol_tex);
79 glTexImage3D(GL_TEXTURE_3D, 0, int_fmt, xsz, ysz, zsz, 0, GL_RGBA, GL_FLOAT, 0);
80
81 float *slice = new float[xsz * ysz * 4];
82
83 for(int i=0; i<zsz; i++) {
84 float z = (float)i;
85 float *pptr = slice;
86
87 for(int j=0; j<ysz; j++) {
88 float y = (float)j;
89 for(int k=0; k<xsz; k++) {
90 float x = (float)k;
91
92 // value in alpha channel
93 pptr[3] = vol->valuef(x, y, z);
94 // normal in rgb
95 vol->normalf(pptr, x, y, z);
96 // shift normal to the [0,1] range in case we don't have tex_float
97 pptr[0] = pptr[0] * 0.5 + 0.5;
98 pptr[1] = pptr[1] * 0.5 + 0.5;
99 pptr[2] = pptr[2] * 0.5 + 0.5;
100
101 pptr += 4;
102 }
103 }
104
105 glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, i, xsz, ysz, 1, GL_RGBA, GL_FLOAT, slice);
106 }
107
108 printf("done\n");
109
110 delete [] slice;
111
112 vol_tex_valid = true;
113 }
114
115 if(!xfer_tex_valid) {
116 float pixels[XFER_MAP_SZ * 3];
117 float *pptr = pixels;
118
119 for(int i=0; i<XFER_MAP_SZ; i++) {
120 float x = (float)i / (float)(XFER_MAP_SZ - 1);
121 *pptr++ = xfer[0].value(x);
122 *pptr++ = xfer[1].value(x);
123 *pptr++ = xfer[2].value(x);
124 }
125
126 glBindTexture(GL_TEXTURE_1D, xfer_tex);
127 glTexSubImage1D(GL_TEXTURE_1D, 0, 0, XFER_MAP_SZ, GL_RGB, GL_FLOAT, pixels);
128
129 xfer_tex_valid = true;
130 }
131 }
132
133 void RendererFast::render() const
134 {
135 if(!vol) return;
136
137 glClear(GL_COLOR_BUFFER_BIT);
138
139 glMatrixMode(GL_PROJECTION);
140 glPushMatrix();
141 glLoadIdentity();
142
143 glMatrixMode(GL_MODELVIEW);
144 glPushMatrix();
145 glLoadIdentity();
146
147 glUseProgram(sdr);
148
149 glActiveTexture(GL_TEXTURE0);
150 glBindTexture(GL_TEXTURE_3D, vol_tex);
151 glActiveTexture(GL_TEXTURE1);
152 glBindTexture(GL_TEXTURE_1D, xfer_tex);
153
154 set_uniform_int(sdr, "vol_tex", 0);
155 set_uniform_int(sdr, "xfer_tex", 1);
156
157 glBegin(GL_QUADS);
158 glTexCoord3f(0, 0, 0.5); glVertex2f(-1, -1);
159 glTexCoord3f(1, 0, 0.5); glVertex2f(1, -1);
160 glTexCoord3f(1, 1, 0.5); glVertex2f(1, 1);
161 glTexCoord3f(0, 1, 0.5); glVertex2f(-1, 1);
162 glEnd();
163
164 glUseProgram(0);
165
166 glMatrixMode(GL_PROJECTION);
167 glPopMatrix();
168 glMatrixMode(GL_MODELVIEW);
169 glPopMatrix();
170 }