nuclear@2: /*
nuclear@2: Stereoscopic tunnel for iOS.
nuclear@2: Copyright (C) 2011  John Tsiombikas <nuclear@member.fsf.org>
nuclear@2: 
nuclear@2: This program is free software: you can redistribute it and/or modify
nuclear@2: it under the terms of the GNU General Public License as published by
nuclear@2: the Free Software Foundation, either version 3 of the License, or
nuclear@2: (at your option) any later version.
nuclear@2: 
nuclear@2: This program is distributed in the hope that it will be useful,
nuclear@2: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@2: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@2: GNU General Public License for more details.
nuclear@2: 
nuclear@2: You should have received a copy of the GNU General Public License
nuclear@2: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@2: */
nuclear@2: 
nuclear@2: #include <math.h>
nuclear@2: #include "opengl.h"
nuclear@2: #include "cam.h"
nuclear@2: #include "sanegl.h"
nuclear@2: 
nuclear@2: #define DEG_TO_RAD(x)	(M_PI * (x) / 180.0)
nuclear@2: 
nuclear@2: typedef struct vec3 {
nuclear@2: 	float x, y, z;
nuclear@2: } vec3_t;
nuclear@2: 
nuclear@2: /* viewing parameters */
nuclear@2: #define DEF_THETA	0
nuclear@2: #define DEF_PHI		0
nuclear@2: #define DEF_DIST	0
nuclear@2: #define DEF_X		0
nuclear@2: #define DEF_Y		0
nuclear@2: #define DEF_Z		0
nuclear@2: 
nuclear@2: static float cam_theta = DEF_THETA, cam_phi = DEF_PHI;
nuclear@2: static float cam_dist = DEF_DIST;
nuclear@2: static vec3_t cam_pos = {DEF_X, DEF_Y, DEF_Z};
nuclear@2: static float cam_speed = 1.0;
nuclear@2: 
nuclear@2: /* projection parameters */
nuclear@2: #define DEF_VFOV	45.0
nuclear@2: #define DEF_ASPECT	1.3333333
nuclear@2: #define DEF_NEAR	1.0
nuclear@2: #define DEF_FAR		1000.0
nuclear@2: 
nuclear@2: static float vfov = DEF_VFOV;
nuclear@2: static float aspect = DEF_ASPECT;
nuclear@2: static float nearclip = DEF_NEAR, farclip = DEF_FAR;
nuclear@2: 
nuclear@2: /* stereo parameters */
nuclear@2: #define DEF_EYE_SEP		0.1
nuclear@2: #define DEF_FOCUS_DIST	1.0
nuclear@2: 
nuclear@2: static float eye_sep = DEF_EYE_SEP;
nuclear@2: static float focus_dist = DEF_FOCUS_DIST;
nuclear@2: 
nuclear@2: 
nuclear@2: static float rot_speed = 0.5;
nuclear@2: static float zoom_speed = 0.1;
nuclear@2: 
nuclear@2: void cam_reset(void)
nuclear@2: {
nuclear@2: 	cam_reset_view();
nuclear@2: 	cam_reset_proj();
nuclear@2: 	cam_reset_stereo();
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_reset_view(void)
nuclear@2: {
nuclear@2: 	cam_theta = DEF_THETA;
nuclear@2: 	cam_phi = DEF_PHI;
nuclear@2: 	cam_dist = DEF_DIST;
nuclear@2: 	cam_pos.x = DEF_X;
nuclear@2: 	cam_pos.y = DEF_Y;
nuclear@2: 	cam_pos.z = DEF_Z;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_reset_proj(void)
nuclear@2: {
nuclear@2: 	vfov = DEF_VFOV;
nuclear@2: 	aspect = DEF_ASPECT;
nuclear@2: 	nearclip = DEF_NEAR;
nuclear@2: 	farclip = DEF_FAR;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_reset_stereo(void)
nuclear@2: {
nuclear@2: 	eye_sep = DEF_EYE_SEP;
nuclear@2: 	focus_dist = DEF_FOCUS_DIST;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_pan(int dx, int dy)
nuclear@2: {
nuclear@2: 	float dxf = dx * cam_speed;
nuclear@2: 	float dyf = dy * cam_speed;
nuclear@2: 	float angle = -DEG_TO_RAD(cam_theta);
nuclear@2: 
nuclear@2: 	cam_pos.x += cos(angle) * dxf + sin(angle) * dyf;
nuclear@2: 	cam_pos.z += -sin(angle) * dxf + cos(angle) * dyf;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_height(int dh)
nuclear@2: {
nuclear@2: 	cam_pos.y += dh * cam_speed;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_rotate(int dx, int dy)
nuclear@2: {
nuclear@2: 	cam_theta += dx * rot_speed;
nuclear@2: 	cam_phi += dy * rot_speed;
nuclear@2: 
nuclear@2: 	if(cam_phi < -90) cam_phi = -90;
nuclear@2: 	if(cam_phi > 90) cam_phi = 90;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_zoom(int dz)
nuclear@2: {
nuclear@2: 	cam_dist += dz * zoom_speed;
nuclear@2: 	if(cam_dist < 0.001) {
nuclear@2: 		cam_dist = 0.001;
nuclear@2: 	}
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_clip(float n, float f)
nuclear@2: {
nuclear@2: 	nearclip = n;
nuclear@2: 	farclip = f;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_fov(float f)
nuclear@2: {
nuclear@2: 	vfov = f;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_aspect(float a)
nuclear@2: {
nuclear@2: 	aspect = a;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_separation(float s)
nuclear@2: {
nuclear@2: 	eye_sep = s;
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_focus_dist(float d)
nuclear@2: {
nuclear@2: 	focus_dist = d;
nuclear@2: 
nuclear@2: 	cam_separation(d / 30.0);
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_view_matrix(void)
nuclear@2: {
nuclear@2: 	cam_stereo_view_matrix(CAM_CENTER);
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_stereo_view_matrix(int eye)
nuclear@2: {
nuclear@2: 	static const float offs_sign[] = {0.0f, 0.5f, -0.5f};	/* center, left, right */
nuclear@2: 	float offs = eye_sep * offs_sign[eye];
nuclear@2: 
nuclear@2: 	gl_translatef(offs, 0, 0);
nuclear@2: 
nuclear@2: 	gl_translatef(0, 0, -cam_dist);
nuclear@2: 	gl_rotatef(cam_phi, 1, 0, 0);
nuclear@2: 	gl_rotatef(cam_theta, 0, 1, 0);
nuclear@2: 	gl_translatef(-cam_pos.x, -cam_pos.y, -cam_pos.z);
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_proj_matrix(void)
nuclear@2: {
nuclear@2: 	cam_stereo_proj_matrix(CAM_CENTER);
nuclear@2: }
nuclear@2: 
nuclear@2: void cam_stereo_proj_matrix(int eye)
nuclear@2: {
nuclear@2: 	float vfov_rad = M_PI * vfov / 180.0;
nuclear@2: 	float top = nearclip * tan(vfov_rad * 0.5);
nuclear@2: 	float right = top * aspect;
nuclear@2: 
nuclear@2: 	static const float offs_sign[] = {0.0f, 1.0, -1.0};	/* center, left, right */
nuclear@2: 	float frust_shift = offs_sign[eye] * (eye_sep * 0.5 * nearclip / focus_dist);
nuclear@2: 
nuclear@2: 	gl_frustum(-right + frust_shift, right + frust_shift, -top, top, nearclip, farclip);
nuclear@2: }