1 | #include "common.h"
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2 | #include "Camera.h"
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3 | #include "glInterface.h"
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4 |
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5 |
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6 | namespace CHCDemo
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7 | {
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8 |
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9 |
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10 | Camera::Camera()
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11 | {
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12 | mWidth = 100;
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13 | mHeight = 100;
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14 | mFovy = 90.0f * M_PI / 180.0f;
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15 | }
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16 |
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17 |
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18 | Camera::Camera(int width, int height, float fieldOfView)
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19 | {
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20 | mWidth = width;
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21 | mHeight = height;
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22 |
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23 | mFovy = fieldOfView * M_PI / 180.0f;
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24 | }
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25 |
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26 |
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27 | void Camera::Precompute()
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28 | {
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29 | mDirection.Normalize();
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30 |
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31 | Vector3 side = CrossProd(Vector3(0, 1, 0), mDirection);
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32 | mUp = -Normalize(CrossProd(side, mDirection));
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33 | mRight = -Normalize(CrossProd(mDirection, mUp));
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34 |
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35 | float k = tan(mFovy/2);
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36 | mUp *= k;
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37 | mRight *= k*mWidth/mHeight;
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38 | }
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39 |
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40 |
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41 | void Camera::SetPosition(const Vector3 &pos)
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42 | {
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43 | mPosition = pos;
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44 | Precompute();
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45 | }
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46 |
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47 |
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48 | void Camera::SetDirection(const Vector3 &dir)
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49 | {
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50 | mDirection = dir;
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51 | Precompute();
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52 | }
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53 |
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54 |
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55 | void Camera::LookInBox(const AxisAlignedBox3 &box)
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56 | {
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57 | mDirection = Vector3(0, 0, 1);
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58 | mPosition = box.Center();
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59 | mPosition.y += 50;
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60 |
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61 | Precompute();
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62 | }
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63 |
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64 |
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65 | void Camera::LookAtBox(const AxisAlignedBox3 &box)
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66 | {
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67 | mDirection = Vector3(0, 0, box.Min().z - box.Max().z);
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68 | mPosition = Vector3(0);//box.Max() - mDirection;
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69 |
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70 | Precompute();
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71 | }
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72 |
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73 |
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74 | void Camera::GetProjectionMatrix(Matrix4x4 &mat)
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75 | {
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76 | glGetFloatv(GL_PROJECTION_MATRIX, (float *)mat.x);
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77 | }
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78 |
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79 |
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80 | void Camera::GetModelViewMatrix(Matrix4x4 &mat)
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81 | {
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82 | glGetFloatv(GL_MODELVIEW_MATRIX, (float *)mat.x);
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83 | }
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84 |
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85 |
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86 | void Camera::CalcFrustum(Frustum &frustum)
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87 | {
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88 | // we grab the plane equations of the six clipplanes of the viewfrustum
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89 | Matrix4x4 matViewing, matProjectionView;
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90 |
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91 | GetModelViewMatrix(matViewing);
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92 | GetProjectionMatrix(matProjectionView);
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93 |
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94 | matProjectionView = matViewing * matProjectionView;
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95 | //matProjectionView = matProjectionView * matViewing;
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96 |
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97 | float planes[6][4];
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98 |
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99 |
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100 | //////////
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101 | //-- extract the plane equations
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102 |
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103 | for (int i = 0; i < 4; ++ i)
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104 | {
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105 | planes[0][i] = matProjectionView.x[i][3] - matProjectionView.x[i][0]; // right plane
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106 | planes[1][i] = matProjectionView.x[i][3] + matProjectionView.x[i][0]; // left plane
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107 | planes[2][i] = matProjectionView.x[i][3] + matProjectionView.x[i][1]; // bottom plane
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108 | planes[3][i] = matProjectionView.x[i][3] - matProjectionView.x[i][1]; // top plane
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109 | planes[4][i] = matProjectionView.x[i][3] - matProjectionView.x[i][2]; // far plane
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110 | planes[5][i] = matProjectionView.x[i][3] + matProjectionView.x[i][2]; // near plane
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111 | }
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112 |
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113 |
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114 | ////////////
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115 | //-- normalize the coefficients
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116 |
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117 | for (int i = 0; i < 6; ++ i)
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118 | {
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119 | // the clipping planes look outward the frustum,
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120 | // so distances > 0 mean that a point is outside
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121 | float fInvLength = -1.0f /
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122 | sqrt(planes[i][0] * planes[i][0] +
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123 | planes[i][1] * planes[i][1] +
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124 | planes[i][2] * planes[i][2]);
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125 |
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126 | planes[i][0] *= fInvLength;
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127 | planes[i][1] *= fInvLength;
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128 | planes[i][2] *= fInvLength;
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129 | planes[i][3] *= fInvLength;
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130 |
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131 | frustum.mClipPlanes[i].mNormal = Vector3(planes[i][0], planes[i][1], planes[i][2]);
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132 | frustum.mClipPlanes[i].mD = planes[i][3];
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133 | }
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134 | }
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135 |
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136 |
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137 | void Camera::Frustum::CalcNPVertexIndices(int *indices)
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138 | {
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139 | for (int i = 0; i < 6; ++ i)
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140 | {
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141 | // n-vertex
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142 | indices[i * 2 + 0] = AxisAlignedBox3::GetIndexNearestVertex(mClipPlanes[i].mNormal);
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143 | // p-vertex
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144 | indices[i * 2 + 1] = AxisAlignedBox3::GetIndexFarthestVertex(mClipPlanes[i].mNormal);
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145 | }
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146 | }
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147 |
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148 |
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149 | void Camera::SetupCameraView()
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150 | {
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151 | glLoadIdentity();
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152 | gluLookAt(mPosition.x, mPosition.y, mPosition.z,
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153 | mPosition.x + mDirection.x, mPosition.y + mDirection.y, mPosition.z + mDirection.z,
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154 | mUp.x, mUp.y, mUp.z);
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155 |
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156 | //std::cout << "dir: " << mDirection << " pos: " << mPosition << " up: " << mUp << std::endl;
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157 | }
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158 |
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159 |
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160 |
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161 | void Camera::ComputePoints(Vector3 &ftl, Vector3 &ftr, Vector3 &fbl, Vector3 &fbr,
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162 | Vector3 &ntl, Vector3 &ntr, Vector3 &nbl, Vector3 &nbr)
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163 | {
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164 | float z_near = 0.1f;
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165 | float z_far = 300;
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166 |
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167 | const float h_near = 2.0f * tan(mFovy / 2) * z_near;
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168 | const float w_near = h_near * GetAspect();
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169 | const float h_far = 2.0f * tan(mFovy / 2) * z_far;
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170 | const float w_far = h_far * GetAspect();
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171 |
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172 | const Vector3 view = mDirection;
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173 | const Vector3 fc = mPosition + view * z_far;
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174 |
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175 | const Vector3 up = mUp;
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176 |
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177 | const Vector3 right = mRight;
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178 |
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179 | Vector3 t1, t2;
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180 |
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181 | t1 = h_far * 0.5f * up;
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182 | t2 = w_far * 0.5f * right;
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183 |
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184 | ftl = fc + t1 - t2;
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185 | ftr = fc + t1 + t2;
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186 | fbl = fc - t1 - t2;
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187 | fbr = fc - t1 + t2;
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188 |
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189 | const Vector3 nc = mPosition + mDirection * z_near;
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190 |
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191 | t1 = h_near * 0.5f * up;
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192 | t2 = w_near * 0.5f * right;
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193 |
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194 | ntl = nc + t1 - t2;
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195 | ntr = nc + t1 + t2;
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196 | nbl = nc - t1 - t2;
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197 | nbr = nc - t1 + t2;
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198 | }
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199 |
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200 |
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201 | }
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202 |
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