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/vmath.h>
nuclear@0: #include "rend.h"
nuclear@0: 
nuclear@0: static bool init();
nuclear@0: static void cleanup();
nuclear@0: static void display();
nuclear@0: static void reshape(int x, int y);
nuclear@0: static void keyb(unsigned char key, int x, int y);
nuclear@0: static void mouse(int bn, int st, int x, int y);
nuclear@0: static void motion(int x, int y);
nuclear@0: static void resize_fbtex(int xsz, int ysz);
nuclear@0: static void update_fbtex();
nuclear@0: static int next_pow2(int x);
nuclear@0: static float dfunc(float x, float y, float z);
nuclear@0: 
nuclear@0: static int pix_scale = 2;
nuclear@0: static int width = 640;
nuclear@0: static int height = 384;
nuclear@0: static int win_width = width * pix_scale;
nuclear@0: static int win_height = height * pix_scale;
nuclear@0: 
nuclear@0: static float *pixels;
nuclear@0: static unsigned int tex;
nuclear@0: static int tex_width, tex_height;
nuclear@0: 
nuclear@0: static float cam_theta, cam_phi = 25, cam_dist = 10;
nuclear@0: 
nuclear@0: 
nuclear@0: int main(int argc, char **argv)
nuclear@0: {
nuclear@0: 	glutInit(&argc, argv);
nuclear@0: 	glutInitWindowSize(win_width, win_height);
nuclear@0: 	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
nuclear@0: 	glutCreateWindow("distance field raytracer");
nuclear@0: 
nuclear@0: 	glutDisplayFunc(display);
nuclear@0: 	glutReshapeFunc(reshape);
nuclear@0: 	glutKeyboardFunc(keyb);
nuclear@0: 	glutMouseFunc(mouse);
nuclear@0: 	glutMotionFunc(motion);
nuclear@0: 
nuclear@0: 	if(!init()) {
nuclear@0: 		return 1;
nuclear@0: 	}
nuclear@0: 	atexit(cleanup);
nuclear@0: 
nuclear@0: 	glutMainLoop();
nuclear@0: 	return 0;
nuclear@0: }
nuclear@0: 
nuclear@0: static bool init()
nuclear@0: {
nuclear@0: 	glewInit();
nuclear@0: 
nuclear@0: 	glEnable(GL_CULL_FACE);
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_LINEAR);
nuclear@0: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@0: 
nuclear@0: 	glEnable(GL_TEXTURE_2D);
nuclear@0: 
nuclear@0: 	set_distance_function(dfunc);
nuclear@0: 
nuclear@0: 	return true;
nuclear@0: }
nuclear@0: 
nuclear@0: static void cleanup()
nuclear@0: {
nuclear@0: 	glDeleteTextures(1, &tex);
nuclear@0: }
nuclear@0: 
nuclear@0: static void display()
nuclear@0: {
nuclear@0: 	Matrix4x4 cmat;
nuclear@0: 	cmat.translate(Vector3(0, 0, -cam_dist));
nuclear@0: 	cmat.rotate(Vector3(1, 0, 0), DEG_TO_RAD(cam_phi));
nuclear@0: 	cmat.rotate(Vector3(0, 1, 0), DEG_TO_RAD(cam_theta));
nuclear@0: 
nuclear@0: 	set_camera_matrix(cmat);
nuclear@0: 	render();
nuclear@0: 	update_fbtex();
nuclear@0: 
nuclear@0: 	glMatrixMode(GL_TEXTURE);
nuclear@0: 	glLoadIdentity();
nuclear@0: 	glScalef((float)tex_width / (float)width, (float)tex_height / (float)height, 1);
nuclear@0: 
nuclear@0: 	glBegin(GL_QUADS);
nuclear@0: 	glTexCoord2f(0, 0); glVertex2f(-1, -1);
nuclear@0: 	glTexCoord2f(1, 0); glVertex2f(1, -1);
nuclear@0: 	glTexCoord2f(1, 1); glVertex2f(1, 1);
nuclear@0: 	glTexCoord2f(0, 1); glVertex2f(-1, 1);
nuclear@0: 	glEnd();
nuclear@0: 
nuclear@0: 	glutSwapBuffers();
nuclear@0: 	assert(glGetError() == GL_NO_ERROR);
nuclear@0: }
nuclear@0: 
nuclear@0: static void reshape(int x, int y)
nuclear@0: {
nuclear@0: 	static int prev_x , prev_y;
nuclear@0: 
nuclear@0: 	glViewport(0, 0, x, y);
nuclear@0: 	resize_fbtex(x, y);
nuclear@0: 
nuclear@0: 	if(x != prev_x || y != prev_y) {
nuclear@0: 		delete [] pixels;
nuclear@0: 		pixels = new float[x * y * 4];
nuclear@0: 		set_framebuffer(x, y, pixels);
nuclear@0: 		prev_x = x;
nuclear@0: 		prev_y = y;
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: static void resize_fbtex(int xsz, int ysz)
nuclear@0: {
nuclear@0: 	int txsz = next_pow2(xsz);
nuclear@0: 	int tysz = next_pow2(ysz);
nuclear@0: 
nuclear@0: 	if(txsz > tex_width || tysz > tex_height) {
nuclear@0: 		tex_width = txsz;
nuclear@0: 		tex_height = tysz;
nuclear@0: 
nuclear@0: 		glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0: 		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, txsz, tysz, 0, GL_RGBA, GL_FLOAT, 0);
nuclear@0: 	}
nuclear@0: }
nuclear@0: 
nuclear@0: static void update_fbtex()
nuclear@0: {
nuclear@0: 	glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0: 	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RGBA, GL_FLOAT, pixels);
nuclear@0: }
nuclear@0: 
nuclear@0: static int next_pow2(int x)
nuclear@0: {
nuclear@0: 	--x;
nuclear@0: 	x |= x >> 1;
nuclear@0: 	x |= x >> 2;
nuclear@0: 	x |= x >> 4;
nuclear@0: 	x |= x >> 8;
nuclear@0: 	x |= x >> 16;
nuclear@0: 	return x + 1;
nuclear@0: }
nuclear@0: 
nuclear@0: static float dfunc(float x, float y, float z)
nuclear@0: {
nuclear@0: 	return sqrt(x*x + y*y + z*z) - 1.0;
nuclear@0: }
nuclear@0: 
nuclear@0: static 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: }
nuclear@0: 
nuclear@0: static int prev_x, prev_y;
nuclear@0: static bool bnstate[8];
nuclear@0: 
nuclear@0: static void mouse(int bn, int st, int x, int y)
nuclear@0: {
nuclear@0: 	bnstate[bn - GLUT_LEFT_BUTTON] = st == GLUT_DOWN;
nuclear@0: 	prev_x = x;
nuclear@0: 	prev_y = y;
nuclear@0: }
nuclear@0: 
nuclear@0: static void motion(int x, int y)
nuclear@0: {
nuclear@0: 	int dx = x - prev_x;
nuclear@0: 	int dy = y - prev_y;
nuclear@0: 	prev_x = x;
nuclear@0: 	prev_y = y;
nuclear@0: 
nuclear@0: 	if(!dx && !dy) return;
nuclear@0: 
nuclear@0: 	if(bnstate[0]) {
nuclear@0: 		cam_theta -= dx * 0.5;
nuclear@0: 		cam_phi -= dy * 0.5;
nuclear@0: 
nuclear@0: 		if(cam_phi < -90) cam_phi = -90;
nuclear@0: 		if(cam_phi > 90) cam_phi = 90;
nuclear@0: 		glutPostRedisplay();
nuclear@0: 	}
nuclear@0: 	if(bnstate[2]) {
nuclear@0: 		cam_dist += dy * 0.1;
nuclear@0: 		if(cam_dist < 0.0) cam_dist = 0.0;
nuclear@0: 		glutPostRedisplay();
nuclear@0: 	}
nuclear@0: }