[37] | 1 | /* |
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| 2 | |
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| 3 | Brian Curless |
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| 4 | |
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| 5 | Computer Graphics Laboratory |
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| 6 | Stanford University |
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| 7 | |
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| 8 | --------------------------------------------------------------------- |
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| 9 | |
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| 10 | Copyright (1997) The Board of Trustees of the Leland Stanford Junior |
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| 11 | University. Except for commercial resale, lease, license or other |
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| 12 | commercial transactions, permission is hereby given to use, copy, |
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| 13 | modify this software for academic purposes only. No part of this |
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| 14 | software or any derivatives thereof may be used in the production of |
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| 15 | computer models for resale or for use in a commercial |
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| 16 | product. STANFORD MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND |
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| 17 | CONCERNING THIS SOFTWARE. No support is implied or provided. |
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| 18 | |
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| 19 | */ |
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| 20 | |
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| 21 | |
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| 22 | #include "perspective.h" |
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| 23 | #include "vrip.h" |
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| 24 | #include "configure.h" |
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| 25 | #include "vripGlobals.h" |
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| 26 | |
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| 27 | |
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| 28 | Vec3f thePerspViewRay; |
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| 29 | Vec3f theCOP; |
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| 30 | OrthoShear *thePerspShear; |
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| 31 | float theFocalLength; |
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| 32 | |
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| 33 | OrthoShear * |
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| 34 | initPersp(Quaternion &quat, Vec3f &trans, Vec3f ¢er, |
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| 35 | float resolution) |
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| 36 | { |
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| 37 | Vec3f vec, dir, ctr; |
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| 38 | Matrix4f mrot, mtrans, mpermute, mflipz; |
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| 39 | Matrix4f mrotz, mtransyz, mshear, mprod; |
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| 40 | Matrix4f mrotzinv, mtransyzinv, mshearinv; |
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| 41 | float dot; |
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| 42 | Matrix4f mrotx, mrotxinv; |
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| 43 | |
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| 44 | ctr = center; |
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| 45 | thePerspViewRay.setValue(PerspectiveDir); |
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| 46 | theCOP.setValue(PerspectiveCOP); |
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| 47 | |
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| 48 | // Set up the pose matrices |
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| 49 | quat.toMatrix(mrot); |
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| 50 | mtrans.makeIdentity(); |
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| 51 | mtrans.translate(trans); |
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| 52 | |
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| 53 | // Transform the COP and center ray |
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| 54 | mrot.multVec(thePerspViewRay, vec); |
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| 55 | thePerspViewRay.setValue(vec); |
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| 56 | mrot.multVec(theCOP, vec); |
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| 57 | theCOP.setValue(vec); |
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| 58 | theCOP += trans; |
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| 59 | |
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| 60 | if (Verbose) { |
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| 61 | printf("\nCOP: (%f, %f, %f)\n", theCOP.x, theCOP.y, theCOP.z); |
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| 62 | printf("View direction: (%f, %f, %f)\n", thePerspViewRay.x, thePerspViewRay.y, thePerspViewRay.z); |
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| 63 | } |
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| 64 | |
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| 65 | vec3f rayDir; |
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| 66 | rayDir[0] = thePerspViewRay.x; |
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| 67 | rayDir[1] = thePerspViewRay.y; |
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| 68 | rayDir[2] = thePerspViewRay.z; |
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| 69 | OrthoShear *shear = computeShear(rayDir); |
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| 70 | thePerspShear = shear; |
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| 71 | |
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| 72 | // Set up permutation matrix |
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| 73 | |
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| 74 | mpermute.makeIdentity(); |
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| 75 | if (shear->axis == X_AXIS) { |
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| 76 | mpermute.m[0][0] = 0; |
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| 77 | mpermute.m[0][2] = 1; |
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| 78 | mpermute.m[2][2] = 0; |
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| 79 | mpermute.m[2][0] = 1; |
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| 80 | } |
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| 81 | else if (shear->axis == Y_AXIS) { |
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| 82 | mpermute.m[1][1] = 0; |
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| 83 | mpermute.m[1][2] = 1; |
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| 84 | mpermute.m[2][2] = 0; |
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| 85 | mpermute.m[2][1] = 1; |
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| 86 | } |
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| 87 | |
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| 88 | // Update the COP and center of image plane in the new coordinate system |
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| 89 | mpermute.multVec(theCOP, vec); |
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| 90 | theCOP.setValue(vec); |
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| 91 | mpermute.multVec(ctr, vec); |
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| 92 | ctr.setValue(vec); |
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| 93 | |
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| 94 | // Set up flip matrix |
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| 95 | mflipz.makeIdentity(); |
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| 96 | if (shear->flip) |
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| 97 | mflipz.m[2][2] = -1; |
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| 98 | |
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| 99 | |
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| 100 | // Update the COP and image center in the new flipped coordinate system |
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| 101 | mflipz.multVec(theCOP, vec); |
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| 102 | theCOP.setValue(vec); |
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| 103 | mflipz.multVec(ctr, vec); |
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| 104 | ctr.setValue(vec); |
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| 105 | |
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| 106 | Matrix4f msh; |
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| 107 | mshear.makeIdentity(); |
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| 108 | mshear.m[0][2] = shear->sx; |
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| 109 | mshear.m[1][2] = shear->sy; |
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| 110 | |
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| 111 | // Update the COP and image center |
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| 112 | mshear.multVec(theCOP, vec); |
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| 113 | theCOP.setValue(vec); |
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| 114 | mshear.multVec(ctr, vec); |
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| 115 | ctr.setValue(vec); |
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| 116 | |
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| 117 | theFocalLength = ctr.z - theCOP.z; |
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| 118 | |
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| 119 | if (Verbose) { |
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| 120 | printf("Axis = %d (x=%d, y=%d, z=%d), flip = %d, sx = %f, sy = %f\n", |
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| 121 | shear->axis, X_AXIS, Y_AXIS, Z_AXIS, shear->flip, shear->sx, shear->sy); |
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| 122 | printf("\nTransformed COP: (%f, %f, %f)\n", theCOP.x, theCOP.y, theCOP.z); |
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| 123 | printf("\nFocal length: %f\n", theFocalLength); |
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| 124 | } |
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| 125 | |
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| 126 | return shear; |
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| 127 | } |
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| 128 | |
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| 129 | |
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| 130 | void |
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| 131 | applyPersp(Vec3f &vin, Vec3f &vout) { |
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| 132 | // apply shear |
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| 133 | vout.x = vin.x + vin.z*thePerspShear->sx; |
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| 134 | vout.y = vin.y + vin.z*thePerspShear->sy; |
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| 135 | |
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| 136 | // translate eye to origin |
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| 137 | vout.x = vout.x - theCOP.x; |
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| 138 | vout.y = vout.y - theCOP.y; |
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| 139 | |
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| 140 | // apply projection |
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| 141 | vout.x = vout.x*theFocalLength/(vin.z - theCOP.z); |
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| 142 | vout.y = vout.y*theFocalLength/(vin.z - theCOP.z); |
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| 143 | |
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| 144 | vout.z = vin.z; |
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| 145 | } |
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| 146 | |
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| 147 | |
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| 148 | void |
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| 149 | applyInvPersp(Vec3f &vin, Vec3f &vout) |
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| 150 | { |
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| 151 | // un-project |
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| 152 | vout.x = vin.x*(vin.z - theCOP.z)/theFocalLength; |
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| 153 | vout.y = vin.y*(vin.z - theCOP.z)/theFocalLength; |
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| 154 | |
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| 155 | // undo translation of eye to origin |
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| 156 | vout.x = vout.x + theCOP.x; |
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| 157 | vout.y = vout.y + theCOP.y; |
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| 158 | |
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| 159 | // un-apply shear |
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| 160 | vout.x = vout.x - vin.z*thePerspShear->sx; |
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| 161 | vout.y = vout.y - vin.z*thePerspShear->sy; |
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| 162 | |
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| 163 | vout.z = vin.z; |
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| 164 | } |
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| 165 | |
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