conworlds

annotate src/camera.cc @ 17:c814f77d177e

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moved to SDL2
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 25 Aug 2014 22:02:08 +0300
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nuclear@0 1 #include <stdio.h>
nuclear@0 2 #include <math.h>
nuclear@0 3 #include "camera.h"
nuclear@0 4
nuclear@0 5 static void calc_sample_pos_rec(int sidx, float xsz, float ysz, float *pos);
nuclear@0 6
nuclear@0 7 Camera::Camera()
nuclear@0 8 {
nuclear@0 9 vfov = M_PI / 4.0;
nuclear@0 10 cached_matrix_valid = false;
nuclear@0 11
nuclear@0 12 rdir_cache_width = rdir_cache_height = 0;
nuclear@0 13 rdir_cache = 0;
nuclear@0 14 }
nuclear@0 15
nuclear@0 16 Camera::Camera(const Vector3 &p)
nuclear@0 17 : pos(p)
nuclear@0 18 {
nuclear@0 19 vfov = M_PI / 4.0;
nuclear@0 20 cached_matrix_valid = false;
nuclear@0 21
nuclear@0 22 rdir_cache_width = rdir_cache_height = 0;
nuclear@0 23 rdir_cache = 0;
nuclear@0 24 }
nuclear@0 25
nuclear@0 26 Camera::~Camera()
nuclear@0 27 {
nuclear@0 28 delete [] rdir_cache;
nuclear@0 29 }
nuclear@0 30
nuclear@0 31 void Camera::set_fov(float vfov)
nuclear@0 32 {
nuclear@0 33 this->vfov = vfov;
nuclear@0 34
nuclear@0 35 // invalidate the dir cache
nuclear@0 36 delete [] rdir_cache;
nuclear@0 37 }
nuclear@0 38
nuclear@0 39 float Camera::get_fov() const
nuclear@0 40 {
nuclear@0 41 return vfov;
nuclear@0 42 }
nuclear@0 43
nuclear@0 44 void Camera::set_position(const Vector3 &pos)
nuclear@0 45 {
nuclear@0 46 this->pos = pos;
nuclear@0 47 cached_matrix_valid = false; // invalidate the cached matrix
nuclear@0 48 }
nuclear@0 49
nuclear@0 50 const Vector3 &Camera::get_position() const
nuclear@0 51 {
nuclear@0 52 return pos;
nuclear@0 53 }
nuclear@0 54
nuclear@0 55 const Matrix4x4 &Camera::get_matrix() const
nuclear@0 56 {
nuclear@0 57 if(!cached_matrix_valid) {
nuclear@0 58 calc_matrix(&cached_matrix);
nuclear@0 59 cached_matrix_valid = true;
nuclear@0 60 }
nuclear@0 61 return cached_matrix;
nuclear@0 62 }
nuclear@0 63
nuclear@0 64 Vector2 Camera::calc_sample_pos(int x, int y, int xsz, int ysz, int sample) const
nuclear@0 65 {
nuclear@0 66 float ppos[2];
nuclear@0 67 float aspect = (float)xsz / (float)ysz;
nuclear@0 68
nuclear@0 69 float pwidth = 2.0 * aspect / (float)xsz;
nuclear@0 70 float pheight = 2.0 / (float)ysz;
nuclear@0 71
nuclear@0 72 ppos[0] = (float)x * pwidth - aspect;
nuclear@0 73 ppos[1] = 1.0 - (float)y * pheight;
nuclear@0 74
nuclear@0 75 calc_sample_pos_rec(sample, pwidth, pheight, ppos);
nuclear@0 76 return Vector2(ppos[0], ppos[1]);
nuclear@0 77 }
nuclear@0 78
nuclear@0 79 Ray Camera::get_primary_ray(int x, int y, int xsz, int ysz, int sample) const
nuclear@0 80 {
nuclear@0 81 #pragma omp single
nuclear@0 82 {
nuclear@0 83 if(!rdir_cache || rdir_cache_width != xsz || rdir_cache_height != ysz) {
nuclear@0 84 printf("calculating primary ray direction cache\n");
nuclear@0 85
nuclear@0 86 delete [] rdir_cache;
nuclear@0 87 rdir_cache = new Vector3[xsz * ysz];
nuclear@0 88
nuclear@0 89 #pragma omp parallel for
nuclear@0 90 for(int i=0; i<ysz; i++) {
nuclear@0 91 Vector3 *rdir = rdir_cache + i * xsz;
nuclear@0 92 for(int j=0; j<xsz; j++) {
nuclear@0 93 Vector2 ppos = calc_sample_pos(j, i, xsz, ysz, 0);
nuclear@0 94
nuclear@0 95 rdir->x = ppos.x;
nuclear@0 96 rdir->y = ppos.y;
nuclear@0 97 rdir->z = 1.0 / tan(vfov / 2.0);
nuclear@0 98 rdir->normalize();
nuclear@0 99
nuclear@0 100 rdir++;
nuclear@0 101 }
nuclear@0 102 }
nuclear@0 103 rdir_cache_width = xsz;
nuclear@0 104 rdir_cache_height = ysz;
nuclear@0 105 }
nuclear@0 106 }
nuclear@0 107
nuclear@0 108 Ray ray;
nuclear@0 109 ray.origin = pos;
nuclear@0 110 ray.dir = rdir_cache[y * xsz + x];
nuclear@0 111
nuclear@0 112 // transform the ray direction with the camera matrix
nuclear@0 113 Matrix4x4 mat = get_matrix();
nuclear@0 114 mat.m[0][3] = mat.m[1][3] = mat.m[2][3] = mat.m[3][0] = mat.m[3][1] = mat.m[3][2] = 0.0;
nuclear@0 115 mat.m[3][3] = 1.0;
nuclear@0 116
nuclear@0 117 ray.dir = ray.dir.transformed(mat);
nuclear@0 118 return ray;
nuclear@0 119 }
nuclear@0 120
nuclear@0 121 TargetCamera::TargetCamera() {}
nuclear@0 122
nuclear@0 123 TargetCamera::TargetCamera(const Vector3 &pos, const Vector3 &targ)
nuclear@0 124 : Camera(pos), target(targ)
nuclear@0 125 {
nuclear@0 126 }
nuclear@0 127
nuclear@0 128 void TargetCamera::set_target(const Vector3 &targ)
nuclear@0 129 {
nuclear@0 130 target = targ;
nuclear@0 131 cached_matrix_valid = false; // invalidate the cached matrix
nuclear@0 132 }
nuclear@0 133
nuclear@0 134 const Vector3 &TargetCamera::get_target() const
nuclear@0 135 {
nuclear@0 136 return target;
nuclear@0 137 }
nuclear@0 138
nuclear@0 139 void TargetCamera::calc_matrix(Matrix4x4 *mat) const
nuclear@0 140 {
nuclear@0 141 Vector3 up(0, 1, 0);
nuclear@0 142 Vector3 dir = (target - pos).normalized();
nuclear@0 143 Vector3 right = cross_product(up, dir);
nuclear@0 144 up = cross_product(dir, right);
nuclear@0 145
nuclear@0 146 *mat = Matrix4x4(
nuclear@0 147 right.x, up.x, dir.x, pos.x,
nuclear@0 148 right.y, up.y, dir.y, pos.y,
nuclear@0 149 right.z, up.z, dir.z, pos.z,
nuclear@0 150 0.0, 0.0, 0.0, 1.0);
nuclear@0 151 }
nuclear@0 152
nuclear@0 153 void FlyCamera::input_move(float x, float y, float z)
nuclear@0 154 {
nuclear@0 155 static const Vector3 vfwd(0, 0, 1), vright(1, 0, 0);
nuclear@0 156
nuclear@0 157 Vector3 k = vfwd.transformed(rot);
nuclear@0 158 Vector3 i = vright.transformed(rot);
nuclear@0 159 Vector3 j = cross_product(k, i);
nuclear@0 160
nuclear@0 161 pos += i * x + j * y + k * z;
nuclear@0 162 cached_matrix_valid = false;
nuclear@0 163 }
nuclear@0 164
nuclear@0 165 void FlyCamera::input_rotate(float x, float y, float z)
nuclear@0 166 {
nuclear@0 167 Vector3 axis(x, y, z);
nuclear@0 168 float axis_len = axis.length();
nuclear@0 169 if(fabs(axis_len) < 1e-5) {
nuclear@0 170 return;
nuclear@0 171 }
nuclear@0 172 rot.rotate(axis / axis_len, -axis_len);
nuclear@0 173 rot.normalize();
nuclear@0 174
nuclear@0 175 cached_matrix_valid = false;
nuclear@0 176 }
nuclear@0 177
nuclear@0 178 void FlyCamera::calc_matrix(Matrix4x4 *mat) const
nuclear@0 179 {
nuclear@0 180 Matrix4x4 tmat;
nuclear@0 181 tmat.set_translation(pos);
nuclear@0 182
nuclear@0 183 Matrix3x3 rmat = rot.get_rotation_matrix();
nuclear@0 184
nuclear@0 185 *mat = tmat * Matrix4x4(rmat);
nuclear@0 186 }
nuclear@0 187
nuclear@0 188 /* generates a sample position for sample number sidx, in the unit square
nuclear@0 189 * by recursive subdivision and jittering
nuclear@0 190 */
nuclear@0 191 static void calc_sample_pos_rec(int sidx, float xsz, float ysz, float *pos)
nuclear@0 192 {
nuclear@0 193 static const float subpt[4][2] = {
nuclear@0 194 {-0.25, -0.25}, {0.25, -0.25}, {-0.25, 0.25}, {0.25, 0.25}
nuclear@0 195 };
nuclear@0 196
nuclear@0 197 if(!sidx) {
nuclear@0 198 return;
nuclear@0 199 }
nuclear@0 200
nuclear@0 201 /* determine which quadrant to recurse into */
nuclear@0 202 int quadrant = ((sidx - 1) % 4);
nuclear@0 203 pos[0] += subpt[quadrant][0] * xsz;
nuclear@0 204 pos[1] += subpt[quadrant][1] * ysz;
nuclear@0 205
nuclear@0 206 calc_sample_pos_rec((sidx - 1) / 4, xsz / 2, ysz / 2, pos);
nuclear@0 207 }