1 | /* |
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2 | * ---------------------------------------------------------------------- |
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3 | * Lic.h: line integral convolution class |
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4 | * |
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5 | * ====================================================================== |
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6 | * AUTHOR: Wei Qiao <qiaow@purdue.edu> |
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7 | * Purdue Rendering and Perceptualization Lab (PURPL) |
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8 | * |
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9 | * Copyright (c) 2004-2006 Purdue Research Foundation |
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10 | * |
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11 | * See the file "license.terms" for information on usage and |
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12 | * redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES. |
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13 | * ====================================================================== |
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14 | */ |
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15 | |
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16 | |
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17 | #include <stdlib.h> |
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18 | #include <math.h> |
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19 | #include <assert.h> |
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20 | |
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21 | #include "Lic.h" |
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22 | |
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23 | Lic::Lic(int _size, int _width, int _height, float _offset, |
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24 | CGcontext _context, NVISid _vector_field, |
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25 | float scalex, float scaley, float scalez): |
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26 | Renderable(Vector3(0.,0.,0.)), |
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27 | size(_size), |
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28 | offset(_offset), |
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29 | m_g_context(_context), |
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30 | width(_width), |
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31 | height(_height), |
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32 | iframe(0), |
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33 | Npat(64), |
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34 | alpha(0.12*255), |
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35 | tmax(NPIX/(SCALE*NPN)), |
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36 | dmax(SCALE/NPIX) |
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37 | { |
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38 | scale = Vector3(scalex, scaley, scalez); |
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39 | slice_vector = new float[size*size*4]; |
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40 | |
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41 | //initialize the pattern texture |
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42 | glGenTextures(1, &pattern_tex); |
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43 | glBindTexture(GL_TEXTURE_2D, pattern_tex); |
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44 | glTexParameteri(GL_TEXTURE_2D, |
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45 | GL_TEXTURE_WRAP_S, GL_REPEAT); |
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46 | glTexParameteri(GL_TEXTURE_2D, |
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47 | GL_TEXTURE_WRAP_T, GL_REPEAT); |
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48 | glTexParameteri(GL_TEXTURE_2D, |
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49 | GL_TEXTURE_MAG_FILTER, GL_LINEAR); |
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50 | glTexParameteri(GL_TEXTURE_2D, |
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51 | GL_TEXTURE_MIN_FILTER, GL_LINEAR); |
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52 | glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE); |
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53 | |
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54 | //initialize frame buffer objects |
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55 | |
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56 | //render buffer for projecting 3D velocity onto a 2D plane |
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57 | glGenFramebuffersEXT(1, &vel_fbo); |
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58 | glGenTextures(1, &slice_vector_tex); |
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59 | |
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60 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, vel_fbo); |
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61 | |
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62 | glBindTexture(GL_TEXTURE_RECTANGLE_NV, slice_vector_tex); |
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63 | glTexParameterf(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MIN_FILTER, GL_NEAREST); |
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64 | glTexParameterf(GL_TEXTURE_RECTANGLE_NV, GL_TEXTURE_MAG_FILTER, GL_NEAREST); |
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65 | glTexImage2D(GL_TEXTURE_RECTANGLE_NV, 0, |
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66 | GL_FLOAT_RGBA32_NV, size, size, 0, GL_RGBA, GL_FLOAT, NULL); |
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67 | glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, |
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68 | GL_TEXTURE_RECTANGLE_NV, slice_vector_tex, 0); |
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69 | |
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70 | |
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71 | //render buffer for the convolution |
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72 | glGenFramebuffersEXT(1, &fbo); |
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73 | glGenTextures(1, &color_tex); |
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74 | |
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75 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); |
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76 | |
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77 | //initialize color texture for lic |
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78 | glBindTexture(GL_TEXTURE_2D, color_tex); |
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79 | glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); |
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80 | glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); |
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81 | glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, width, height, 0, |
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82 | GL_RGB, GL_INT, NULL); |
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83 | glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, |
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84 | GL_COLOR_ATTACHMENT0_EXT, |
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85 | GL_TEXTURE_2D, color_tex, 0); |
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86 | |
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87 | // Check framebuffer completeness at the end of initialization. |
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88 | CHECK_FRAMEBUFFER_STATUS(); |
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89 | assert(glGetError()==0); |
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90 | |
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91 | m_render_vel_fprog = loadProgram(m_g_context, CG_PROFILE_FP30, CG_SOURCE, "./shaders/render_vel.cg"); |
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92 | m_vel_tex_param_render_vel = cgGetNamedParameter(m_render_vel_fprog, "vel_tex"); |
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93 | m_plane_normal_param_render_vel = cgGetNamedParameter(m_render_vel_fprog, "plane_normal"); |
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94 | cgGLSetTextureParameter(m_vel_tex_param_render_vel, _vector_field); |
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95 | |
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96 | get_slice(); |
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97 | make_patterns(); |
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98 | |
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99 | fprintf(stderr, "initialize lic ...\n"); |
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100 | } |
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101 | |
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102 | Lic::~Lic(){ |
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103 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, vel_fbo); |
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104 | glDeleteTextures(1, &slice_vector_tex); |
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105 | |
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106 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); |
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107 | glDeleteTextures(1, &color_tex); |
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108 | |
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109 | NVISid buffers[2] = {vel_fbo, fbo}; |
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110 | glDeleteFramebuffersEXT(2, buffers); |
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111 | |
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112 | delete slice_vector; |
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113 | } |
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114 | |
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115 | void Lic::make_patterns() |
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116 | { |
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117 | int lut[256]; |
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118 | int phase[NPN][NPN]; |
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119 | GLubyte pat[NPN][NPN][4]; |
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120 | int i, j, k, t; |
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121 | |
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122 | for (i = 0; i < 256; i++) lut[i] = i < 127 ? 0 : 255; |
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123 | for (i = 0; i < NPN; i++) |
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124 | for (j = 0; j < NPN; j++) phase[i][j] = rand() % 256; |
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125 | |
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126 | for (k = 0; k < Npat; k++) { |
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127 | t = k*256/Npat; |
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128 | for (i = 0; i < NPN; i++) |
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129 | for (j = 0; j < NPN; j++) { |
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130 | pat[i][j][0] = |
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131 | pat[i][j][1] = |
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132 | pat[i][j][2] = lut[(t + phase[i][j]) % 255]; |
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133 | pat[i][j][3] = alpha; |
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134 | } |
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135 | |
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136 | glNewList(k + 1, GL_COMPILE); |
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137 | glBindTexture(GL_TEXTURE_2D, pattern_tex); |
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138 | glTexImage2D(GL_TEXTURE_2D, 0, 4, NPN, NPN, 0, |
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139 | GL_RGBA, GL_UNSIGNED_BYTE, pat); |
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140 | glEndList(); |
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141 | } |
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142 | } |
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143 | |
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144 | |
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145 | void Lic::make_magnitudes() |
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146 | { |
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147 | |
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148 | GLubyte mag[NMESH][NMESH][4]; |
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149 | |
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150 | //read vector filed |
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151 | for(int i=0; i<NMESH; i++){ |
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152 | for(int j=0; j<NMESH; j++){ |
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153 | |
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154 | float x=DM*i; |
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155 | float y=DM*j; |
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156 | |
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157 | float magnitude = sqrt(x*x+y*y)/1.414; |
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158 | |
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159 | //from green to red |
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160 | GLubyte r = floor(magnitude*255); |
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161 | GLubyte g = 0; |
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162 | GLubyte b = 255 - r; |
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163 | GLubyte a = 122; |
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164 | |
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165 | mag[i][j][0] = r; |
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166 | mag[i][j][1] = g; |
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167 | mag[i][j][2] = b; |
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168 | mag[i][j][3] = a; |
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169 | } |
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170 | } |
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171 | |
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172 | glGenTextures(1, &mag_tex); |
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173 | glBindTexture(GL_TEXTURE_2D, mag_tex); |
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174 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); |
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175 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); |
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176 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); |
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177 | glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); |
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178 | //glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_BLEND); |
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179 | glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, NMESH, NMESH, 0, GL_RGBA, GL_UNSIGNED_BYTE, mag); |
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180 | |
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181 | } |
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182 | |
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183 | //project 3D vectors to a 2D slice for line integral convolution |
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184 | void Lic::get_slice(){ |
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185 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, vel_fbo); |
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186 | glBindTexture(GL_TEXTURE_RECTANGLE_NV, slice_vector_tex); |
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187 | |
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188 | glClear(GL_COLOR_BUFFER_BIT); |
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189 | |
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190 | glViewport(0, 0, NMESH, NMESH); |
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191 | glMatrixMode(GL_PROJECTION); |
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192 | glLoadIdentity(); |
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193 | gluOrtho2D(0, NMESH, 0, NMESH); |
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194 | glMatrixMode(GL_MODELVIEW); |
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195 | glLoadIdentity(); |
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196 | |
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197 | cgGLBindProgram(m_render_vel_fprog); |
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198 | cgGLEnableTextureParameter(m_vel_tex_param_render_vel); |
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199 | cgGLSetParameter4f(m_plane_normal_param_render_vel, 1., 1., 0., 0); |
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200 | |
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201 | cgGLEnableProfile(CG_PROFILE_FP30); |
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202 | glBegin(GL_QUADS); |
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203 | glTexCoord3f(0., 0., offset); glVertex2f(0., 0.); |
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204 | glTexCoord3f(1., 0., offset); glVertex2f(size, 0.); |
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205 | glTexCoord3f(1., 1., offset); glVertex2f(size, size); |
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206 | glTexCoord3f(0., 1., offset); glVertex2f(0., size); |
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207 | glEnd(); |
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208 | cgGLDisableProfile(CG_PROFILE_FP30); |
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209 | |
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210 | cgGLDisableTextureParameter(m_vel_tex_param_render_vel); |
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211 | |
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212 | //read the vectors |
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213 | glReadPixels(0, 0, NMESH, NMESH, GL_RGBA, GL_FLOAT, slice_vector); |
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214 | /* |
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215 | for(int i=0; i<NMESH*NMESH; i++){ |
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216 | fprintf(stderr, "%f,%f,%f,%f", slice_vector[4*i], slice_vector[4*i+1], slice_vector[4*i+2], slice_vector[4*i+3]); |
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217 | } |
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218 | */ |
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219 | assert(glGetError()==0); |
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220 | } |
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221 | |
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222 | |
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223 | //line integral convolution |
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224 | void Lic::convolve(){ |
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225 | |
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226 | int i, j; |
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227 | float x1, x2, y, px, py; |
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228 | |
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229 | glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo); |
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230 | |
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231 | glViewport(0, 0, (GLsizei) NPIX, (GLsizei) NPIX); |
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232 | glMatrixMode(GL_PROJECTION); |
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233 | glLoadIdentity(); |
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234 | glTranslatef(-1.0, -1.0, 0.0); |
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235 | glScalef(2.0, 2.0, 1.0); |
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236 | |
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237 | //sa = 0.010*cos(iframe*2.0*M_PI/200.0); |
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238 | glBindTexture(GL_TEXTURE_2D, pattern_tex); |
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239 | glEnable(GL_TEXTURE_2D); |
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240 | sa = 0.01; |
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241 | for (i = 0; i < NMESH-1; i++) { |
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242 | x1 = DM*i; x2 = x1 + DM; |
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243 | glBegin(GL_QUAD_STRIP); |
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244 | for (j = 0; j < NMESH-1; j++) { |
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245 | y = DM*j; |
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246 | glTexCoord2f(x1, y); |
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247 | get_velocity(x1, y, &px, &py); |
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248 | glVertex2f(px, py); |
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249 | |
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250 | glTexCoord2f(x2, y); |
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251 | get_velocity(x2, y, &px, &py); |
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252 | glVertex2f(px, py); |
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253 | } |
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254 | glEnd(); |
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255 | } |
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256 | iframe = iframe + 1; |
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257 | |
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258 | glEnable(GL_BLEND); |
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259 | glCallList(iframe % Npat + 1); |
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260 | glBegin(GL_QUAD_STRIP); |
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261 | glTexCoord2f(0.0, 0.0); glVertex2f(0.0, 0.0); |
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262 | glTexCoord2f(0.0, tmax); glVertex2f(0.0, 1.0); |
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263 | glTexCoord2f(tmax, 0.0); glVertex2f(1.0, 0.0); |
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264 | glTexCoord2f(tmax, tmax); glVertex2f(1.0, 1.0); |
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265 | glEnd(); |
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266 | |
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267 | /* |
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268 | //inject dye |
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269 | glDisable(GL_TEXTURE_2D); |
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270 | glColor4f(1.,0.8,0.,1.); |
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271 | glBegin(GL_QUADS); |
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272 | glVertex2d(0.6, 0.6); |
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273 | glVertex2d(0.6, 0.62); |
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274 | glVertex2d(0.62, 0.62); |
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275 | glVertex2d(0.62, 0.6); |
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276 | glEnd(); |
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277 | */ |
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278 | |
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279 | glDisable(GL_BLEND); |
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280 | glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 0, 0, NPIX, NPIX, 0); |
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281 | |
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282 | /* |
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283 | //blend magnitude texture |
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284 | glBindTexture(GL_TEXTURE_2D, mag_tex); |
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285 | glEnable(GL_TEXTURE_2D); |
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286 | glEnable(GL_BLEND); |
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287 | glBegin(GL_QUADS); |
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288 | glTexCoord2f(0.0, 0.0); glVertex2f(0.0, 0.0); |
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289 | glTexCoord2f(0.0, 1.0); glVertex2f(0.0, 1.); |
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290 | glTexCoord2f(1.0, 1.0); glVertex2f(1., 1.); |
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291 | glTexCoord2f(1.0, 0.0); glVertex2f(1., 0.0); |
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292 | glEnd(); |
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293 | */ |
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294 | } |
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295 | |
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296 | void Lic::render(){ display(); } |
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297 | |
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298 | |
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299 | void Lic::display(){ |
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300 | |
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301 | glBindTexture(GL_TEXTURE_2D, color_tex); |
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302 | glEnable(GL_TEXTURE_2D); |
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303 | |
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304 | //draw line integral convolution quad |
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305 | glEnable(GL_DEPTH_TEST); |
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306 | glPushMatrix(); |
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307 | glScalef(scale.x, scale.y, scale.z); |
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308 | |
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309 | glBegin(GL_QUADS); |
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310 | glTexCoord2f(0, 0); glVertex3f(0, 0, offset); |
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311 | glTexCoord2f(1, 0); glVertex3f(1, 0, offset); |
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312 | glTexCoord2f(1, 1); glVertex3f(1, 1, offset); |
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313 | glTexCoord2f(0, 1); glVertex3f(0, 1, offset); |
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314 | glEnd(); |
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315 | |
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316 | glPopMatrix(); |
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317 | |
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318 | glDisable(GL_DEPTH_TEST); |
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319 | glDisable(GL_TEXTURE_2D); |
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320 | } |
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321 | |
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322 | |
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323 | void Lic::get_velocity(float x, float y, float *px, float *py) |
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324 | { |
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325 | float dx, dy, vx, vy, r; |
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326 | |
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327 | int xi = x*NMESH; |
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328 | int yi = y*NMESH; |
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329 | |
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330 | vx = slice_vector[4*(xi+yi*NMESH)]; |
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331 | vy = slice_vector[4*(xi+yi*NMESH)+1]; |
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332 | r = vx*vx + vy*vy; |
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333 | if (r > dmax*dmax) { |
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334 | r = sqrt(r); |
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335 | vx *= dmax/r; |
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336 | vy *= dmax/r; |
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337 | } |
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338 | *px = x + vx; |
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339 | *py = y + vy; |
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340 | } |
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341 | |
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342 | void Lic::set_offset(float v){ |
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343 | offset = v; |
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344 | get_slice(); |
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345 | } |
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