nuclear@0: #include <stdio.h>
nuclear@0: #include <stdlib.h>
nuclear@0: #include <assert.h>
nuclear@0: #include <GL/glew.h>
nuclear@0: #include <GL/glut.h>
nuclear@0: #include <vmath.h>
nuclear@0: #include "sdr.h"
nuclear@0: 
nuclear@0: void disp();
nuclear@0: void reshape(int x, int y);
nuclear@0: void keyb(unsigned char key, int x, int y);
nuclear@0: void mouse(int bn, int state, int x, int y);
nuclear@0: void motion(int x, int y);
nuclear@0: 
nuclear@0: int load_shader();
nuclear@0: unsigned int create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale = 0);
nuclear@0: static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);
nuclear@0: static int round_pow2(int x);
nuclear@0: 
nuclear@0: float cam_theta = 0, cam_phi = 0, cam_dist = 4.0;
nuclear@0: float cam_y = 0;
nuclear@0: 
nuclear@0: unsigned int sdr;
nuclear@0: unsigned int ray_tex;
nuclear@0: Vector2 tex_scale;
nuclear@0: Vector4 seed;
nuclear@0: float err_thres = 0.0075;
nuclear@0: int iter = 10;
nuclear@0: 
nuclear@0: int main(int argc, char **argv)
nuclear@0: {
nuclear@0: 	int xsz, ysz;
nuclear@0: 
nuclear@0: 	seed = Vector4(0.4, 0.0, 0.0, -0.8);
nuclear@0: 
nuclear@0: 	glutInitWindowSize(640, 480);
nuclear@0: 	glutInit(&argc, argv);
nuclear@0: 	glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
nuclear@0: 	glutCreateWindow("Raytraced Fractals");
nuclear@0: 	xsz = glutGet(GLUT_WINDOW_WIDTH);
nuclear@0: 	ysz = glutGet(GLUT_WINDOW_HEIGHT);
nuclear@0: 
nuclear@0: 	glutDisplayFunc(disp);
nuclear@0: 	glutReshapeFunc(reshape);
nuclear@0: 	glutKeyboardFunc(keyb);
nuclear@0: 	glutMouseFunc(mouse);
nuclear@0: 	glutMotionFunc(motion);
nuclear@0: 
nuclear@0: 	glEnable(GL_DEPTH_TEST);
nuclear@0: 	glEnable(GL_LIGHTING);
nuclear@0: 	glEnable(GL_LIGHT0);
nuclear@0: 	glEnable(GL_CULL_FACE);
nuclear@0: 
nuclear@0: 	glewInit();
nuclear@0: 
nuclear@0: 	if(load_shader() == -1) {
nuclear@0: 		return 1;
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	glutMainLoop();
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: int load_shader()
nuclear@0: {
nuclear@0: 	if(sdr) {
nuclear@0: 		free_program(sdr);
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(!(sdr = create_program_load("sdr/sdr.v.glsl", "sdr/julia.p.glsl"))) {
nuclear@0: 		return -1;
nuclear@0: 	}
nuclear@0: 	set_uniform_float4(sdr, "seed", seed.x, seed.y, seed.z, seed.w);
nuclear@0: 	set_uniform_float(sdr, "err_thres", err_thres);
nuclear@0: 	set_uniform_int(sdr, "iter", iter);
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: void disp()
nuclear@0: {
nuclear@0: 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
nuclear@0: 
nuclear@0: 	glMatrixMode(GL_MODELVIEW);
nuclear@0: 	glLoadIdentity();
nuclear@0: 	glRotatef(cam_theta, 0, 1, 0);
nuclear@0: 	glRotatef(cam_phi, 1, 0, 0);
nuclear@0: 	glTranslatef(0, 0, -cam_dist);
nuclear@0: 
nuclear@0: 	float lpos[] = {-1, 1, 3, 0};
nuclear@0: 	glLightfv(GL_LIGHT0, GL_POSITION, lpos);
nuclear@0: 
nuclear@0: 
nuclear@0: 	glMatrixMode(GL_TEXTURE);
nuclear@0: 	glPushMatrix();
nuclear@0: 	glScalef(tex_scale.x, tex_scale.y, 1.0);
nuclear@0: 
nuclear@0: 	glBindTexture(GL_TEXTURE_2D, ray_tex);
nuclear@0: 	glEnable(GL_TEXTURE_2D);
nuclear@0: 	bind_program(sdr);
nuclear@0: 
nuclear@0: 	glBegin(GL_QUADS);
nuclear@0: 	glColor3f(1, 1, 1);
nuclear@0: 	glTexCoord2f(0, 1); glVertex2f(-1, -1);
nuclear@0: 	glTexCoord2f(1, 1); glVertex2f(1, -1);
nuclear@0: 	glTexCoord2f(1, 0); glVertex2f(1, 1);
nuclear@0: 	glTexCoord2f(0, 0); glVertex2f(-1, 1);
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@0: 	bind_program(0);
nuclear@0: 	glDisable(GL_TEXTURE_2D);
nuclear@0: 
nuclear@0: 	glMatrixMode(GL_TEXTURE);
nuclear@0: 	glPopMatrix();
nuclear@0: 
nuclear@0: 	glutSwapBuffers();
nuclear@0: 	assert(glGetError() == GL_NO_ERROR);
nuclear@0: }
nuclear@0: 
nuclear@0: void reshape(int x, int y)
nuclear@0: {
nuclear@0: 	glViewport(0, 0, x, y);
nuclear@0: 	glMatrixMode(GL_PROJECTION);
nuclear@0: 	glLoadIdentity();
nuclear@0: 	gluPerspective(45.0, (float)x / (float)y, 1.0, 1000.0);
nuclear@0: 
nuclear@0: 	if(ray_tex) {
nuclear@0: 		glDeleteTextures(1, &ray_tex);
nuclear@0: 	}
nuclear@0: 	ray_tex = create_ray_texture(x, y, 50.0, &tex_scale);
nuclear@0: }
nuclear@0: 
nuclear@0: 
nuclear@0: void keyb(unsigned char key, int x, int y)
nuclear@0: {
nuclear@0: 	switch(key) {
nuclear@0: 	case 27:
nuclear@0: 		exit(0);
nuclear@0: 
nuclear@0: 	case '-':
nuclear@0: 		if(iter > 1) {
nuclear@0: 			iter--;
nuclear@0: 			set_uniform_int(sdr, "iter", iter);
nuclear@0: 			printf("iter: %d\n", iter);
nuclear@0: 			glutPostRedisplay();
nuclear@0: 		}
nuclear@0: 		break;
nuclear@0: 
nuclear@0: 	case '=':
nuclear@0: 		iter++;
nuclear@0: 		set_uniform_int(sdr, "iter", iter);
nuclear@0: 		printf("iter: %d\n", iter);
nuclear@0: 		glutPostRedisplay();
nuclear@0: 		break;
nuclear@0: 
nuclear@0: 	case ',':
nuclear@0: 		err_thres -= 0.001;
nuclear@0: 		set_uniform_float(sdr, "err_thres", err_thres);
nuclear@0: 		printf("maximum error: %f\n", err_thres);
nuclear@0: 		glutPostRedisplay();
nuclear@0: 		break;
nuclear@0: 
nuclear@0: 	case '.':
nuclear@0: 		err_thres += 0.001;
nuclear@0: 		set_uniform_float(sdr, "err_thres", err_thres);
nuclear@0: 		printf("maximum error: %f\n", err_thres);
nuclear@0: 		glutPostRedisplay();
nuclear@0: 		break;
nuclear@0: 
nuclear@0: 	case 's':
nuclear@0: 		load_shader();
nuclear@0: 		glutPostRedisplay();
nuclear@0: 		break;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: int bnstate[16];
nuclear@0: 
nuclear@0: int prev_x = -1, prev_y;
nuclear@0: void mouse(int bn, int state, int x, int y)
nuclear@0: {
nuclear@0: 	bnstate[bn] = state == GLUT_DOWN ? 1 : 0;
nuclear@0: 	if(state == GLUT_DOWN) {
nuclear@0: 		if(bn == 3) {
nuclear@0: 			cam_dist -= 0.1;
nuclear@0: 			glutPostRedisplay();
nuclear@0: 			if(cam_dist < 0) cam_dist = 0;
nuclear@0: 		} else if(bn == 4) {
nuclear@0: 			cam_dist += 0.1;
nuclear@0: 			glutPostRedisplay();
nuclear@0: 		} else {
nuclear@0: 			prev_x = x;
nuclear@0: 			prev_y = y;
nuclear@0: 		}
nuclear@0: 	} else {
nuclear@0: 		prev_x = -1;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: void motion(int x, int y)
nuclear@0: {
nuclear@0: 	if(bnstate[0]) {
nuclear@0: 		cam_theta += (x - prev_x) * 0.5;
nuclear@0: 		cam_phi += (y - prev_y) * 0.5;
nuclear@0: 
nuclear@0: 		if(cam_phi < -90) cam_phi = -90;
nuclear@0: 		if(cam_phi > 90) cam_phi = 90;
nuclear@0: 
nuclear@0: 		glutPostRedisplay();
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(bnstate[1]) {
nuclear@0: 		cam_y += (y - prev_y) * 0.1;
nuclear@0: 		glutPostRedisplay();
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	if(bnstate[2]) {
nuclear@0: 		cam_dist += (y - prev_y) * 0.1;
nuclear@0: 		glutPostRedisplay();
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	prev_x = x;
nuclear@0: 	prev_y = y;
nuclear@0: }
nuclear@0: 
nuclear@0: unsigned int create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale)
nuclear@0: {
nuclear@0: 	unsigned int tex;
nuclear@0: 	int tex_xsz = round_pow2(xsz);
nuclear@0: 	int tex_ysz = round_pow2(ysz);
nuclear@0: 	float *teximg, *dir;
nuclear@0: 
nuclear@0: 	teximg = new float[3 * tex_xsz * tex_ysz];
nuclear@0: 	dir = teximg;
nuclear@0: 
nuclear@0: 	for(int i=0; i<tex_ysz; i++) {
nuclear@0: 		for(int j=0; j<tex_xsz; j++) {
nuclear@0: 			if(j < xsz && i < ysz) {
nuclear@0: 				Vector3 rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
nuclear@0: 				dir[0] = rdir.x;
nuclear@0: 				dir[1] = rdir.y;
nuclear@0: 				dir[2] = rdir.z;
nuclear@0: 			} else {
nuclear@0: 				dir[0] = dir[1] = 0.0f;
nuclear@0: 				dir[2] = 1.0f;
nuclear@0: 			}
nuclear@0: 
nuclear@0: 			dir += 3;
nuclear@0: 		}
nuclear@0: 	}
nuclear@0: 
nuclear@0: 	glGenTextures(1, &tex);
nuclear@0: 	glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
nuclear@0: 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, teximg);
nuclear@0: 	delete [] teximg;
nuclear@0: 
nuclear@0: 	if(tex_scale) {
nuclear@0: 		tex_scale->x = (float)xsz / (float)tex_xsz;
nuclear@0: 		tex_scale->y = (float)ysz / (float)tex_ysz;
nuclear@0: 	}
nuclear@0: 	return tex;
nuclear@0: }
nuclear@0: 
nuclear@0: static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)
nuclear@0: {
nuclear@0: 	float vfov = M_PI * vfov_deg / 180.0;
nuclear@0: 	float aspect = (float)w / (float)h;
nuclear@0: 
nuclear@0: 	float ysz = 2.0;
nuclear@0: 	float xsz = aspect * ysz;
nuclear@0: 
nuclear@0: 	float px = ((float)x / (float)w) * xsz - xsz / 2.0;
nuclear@0: 	float py = 1.0 - ((float)y / (float)h) * ysz;
nuclear@0: 	float pz = 1.0 / tan(0.5 * vfov);
nuclear@0: 
nuclear@0: 	float mag = sqrt(px * px + py * py + pz * pz);
nuclear@0: 
nuclear@0: 	return Vector3(px / mag, py / mag, pz / mag);
nuclear@0: }
nuclear@0: 
nuclear@0: static int round_pow2(int x)
nuclear@0: {
nuclear@0: 	x--;
nuclear@0: 	x = (x >> 1) | x;
nuclear@0: 	x = (x >> 2) | x;
nuclear@0: 	x = (x >> 4) | x;
nuclear@0: 	x = (x >> 8) | x;
nuclear@0: 	x = (x >> 16) | x;
nuclear@0: 	return x + 1;
nuclear@0: }