nuclear@2: #include <stdio.h>
nuclear@2: #include <stdlib.h>
nuclear@2: #include <assert.h>
nuclear@2: #include "opengl.h"
nuclear@4: #include "erebus.h"
nuclear@2: 
nuclear@2: static bool init();
nuclear@2: static void cleanup();
nuclear@2: static void resize_rtarget(int xsz, int ysz);
nuclear@2: static void update_rect(int x, int y, int xsz, int ysz, float *pixels);
nuclear@4: static void idle();
nuclear@2: static void display();
nuclear@2: static void reshape(int x, int y);
nuclear@2: static void keyb(unsigned char key, int x, int y);
nuclear@2: static void mouse(int bn, int st, int x, int y);
nuclear@2: static int next_pow2(int x);
nuclear@2: 
nuclear@2: static int width, height, rtex_width, rtex_height;
nuclear@2: static unsigned int rtex;
nuclear@2: 
nuclear@4: static erebus *erb;
nuclear@4: static bool render_pending;
nuclear@4: 
nuclear@4: 
nuclear@2: int main(int argc, char **argv)
nuclear@2: {
nuclear@2: 	glutInitWindowSize(1024, 600);
nuclear@2: 	glutInit(&argc, argv);
nuclear@2: 	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
nuclear@2: 	glutCreateWindow("erebus OpenGL frontend");
nuclear@2: 
nuclear@2: 	glutDisplayFunc(display);
nuclear@2: 	glutReshapeFunc(reshape);
nuclear@2: 	glutKeyboardFunc(keyb);
nuclear@2: 	glutMouseFunc(mouse);
nuclear@2: 
nuclear@2: 	if(!init()) {
nuclear@2: 		return 1;
nuclear@2: 	}
nuclear@2: 	atexit(cleanup);
nuclear@2: 
nuclear@2: 	glutMainLoop();
nuclear@2: }
nuclear@2: 
nuclear@2: static bool init()
nuclear@2: {
nuclear@8: 	width = glutGet(GLUT_WINDOW_WIDTH) / 2;
nuclear@8: 	height = glutGet(GLUT_WINDOW_HEIGHT) / 2;
nuclear@5: 
nuclear@4: 	if(!(erb = erb_init())) {
nuclear@4: 		return false;
nuclear@4: 	}
nuclear@4: 	erb_setopti(erb, ERB_OPT_WIDTH, width);
nuclear@4: 	erb_setopti(erb, ERB_OPT_HEIGHT, height);
nuclear@4: 
nuclear@4: 	if(erb_load_scene(erb, "scene") == -1) {
nuclear@4: 		return false;
nuclear@4: 	}
nuclear@4: 
nuclear@4: 	printf("begin rendering\n");
nuclear@4: 	render_pending = true;
nuclear@4: 	glutIdleFunc(idle);
nuclear@4: 	erb_begin_frame(erb, 0);
nuclear@4: 
nuclear@8: 	glEnable(GL_TEXTURE_2D);
nuclear@2: 	return true;
nuclear@2: }
nuclear@2: 
nuclear@2: static void cleanup()
nuclear@2: {
nuclear@4: 	erb_destroy(erb);
nuclear@2: }
nuclear@2: 
nuclear@2: static void resize_rtarget(int xsz, int ysz)
nuclear@2: {
nuclear@2: 	static unsigned char *defpix;
nuclear@2: 
nuclear@8: 	width = xsz / 2;
nuclear@8: 	height = ysz / 2;
nuclear@2: 
nuclear@8: 	if(width <= rtex_width && height <= rtex_height) {
nuclear@2: 		return;
nuclear@2: 	}
nuclear@8: 	rtex_width = next_pow2(width);
nuclear@8: 	rtex_height = next_pow2(height);
nuclear@2: 
nuclear@2: 	printf("resizing framebuffer texture: %dx%d\n", rtex_width, rtex_height);
nuclear@2: 
nuclear@2: 	if(!rtex) {
nuclear@2: 		glGenTextures(1, &rtex);
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	delete [] defpix;
nuclear@2: 	defpix = new unsigned char[rtex_width * rtex_height * 4];
nuclear@2: 	unsigned char *ptr = defpix;
nuclear@2: 	for(int i=0; i<rtex_height; i++) {
nuclear@2: 		for(int j=0; j<rtex_width; j++) {
nuclear@2: 			bool chess = ((i >> 4) & 1) == ((j >> 4) & 1);
nuclear@2: 
nuclear@2: 			int val = chess ? 64 : 48;
nuclear@2: 
nuclear@2: 			*ptr++ = val;
nuclear@2: 			*ptr++ = val;
nuclear@2: 			*ptr++ = val;
nuclear@2: 			*ptr++ = 255;
nuclear@2: 		}
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	glBindTexture(GL_TEXTURE_2D, rtex);
nuclear@2: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
nuclear@2: 	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
nuclear@2: 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB, rtex_width, rtex_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, defpix);
nuclear@2: }
nuclear@2: 
nuclear@2: static void update_rect(int x, int y, int xsz, int ysz, float *pixels)
nuclear@2: {
nuclear@2: 	glBindTexture(GL_TEXTURE_2D, rtex);
nuclear@2: 	glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, xsz, ysz, GL_RGBA, GL_FLOAT, pixels);
nuclear@2: }
nuclear@2: 
nuclear@4: static void idle()
nuclear@4: {
nuclear@4: 	glutPostRedisplay();
nuclear@4: }
nuclear@4: 
nuclear@2: static void display()
nuclear@2: {
nuclear@4: 	if(render_pending) {
nuclear@8: 		if(erb_render(erb, 64) == 0) {
nuclear@4: 			render_pending = false;
nuclear@4: 			glutIdleFunc(0);
nuclear@4: 		}
nuclear@4: 		update_rect(0, 0, width, height, erb_get_framebuffer(erb));
nuclear@4: 	}
nuclear@4: 
nuclear@2: 	float maxu = (float)width / (float)rtex_width;
nuclear@2: 	float maxv = (float)height / (float)rtex_height;
nuclear@2: 
nuclear@2: 	glBegin(GL_QUADS);
nuclear@2: 	glTexCoord2f(0, maxv); glVertex2f(-1, -1);
nuclear@2: 	glTexCoord2f(maxu, maxv); glVertex2f(1, -1);
nuclear@2: 	glTexCoord2f(maxu, 0); glVertex2f(1, 1);
nuclear@2: 	glTexCoord2f(0, 0); glVertex2f(-1, 1);
nuclear@2: 	glEnd();
nuclear@2: 
nuclear@2: 	glutSwapBuffers();
nuclear@2: 	assert(glGetError() == GL_NO_ERROR);
nuclear@2: }
nuclear@2: 
nuclear@2: static void reshape(int x, int y)
nuclear@2: {
nuclear@2: 	glViewport(0, 0, x, y);
nuclear@2: 	resize_rtarget(x, y);
nuclear@4: 
nuclear@4: 	erb_setopti(erb, ERB_OPT_WIDTH, width);
nuclear@4: 	erb_setopti(erb, ERB_OPT_HEIGHT, height);
nuclear@2: }
nuclear@2: 
nuclear@2: static void keyb(unsigned char key, int x, int y)
nuclear@2: {
nuclear@2: 	switch(key) {
nuclear@2: 	case 27:
nuclear@2: 		exit(0);
nuclear@4: 
nuclear@4: 	case ' ':
nuclear@4: 		printf("begin rendering\n");
nuclear@4: 		render_pending = true;
nuclear@4: 		glutIdleFunc(idle);
nuclear@4: 		erb_begin_frame(erb, 0);
nuclear@4: 		break;
nuclear@2: 	}
nuclear@2: }
nuclear@2: 
nuclear@2: static void mouse(int bn, int st, int x, int y)
nuclear@2: {
nuclear@2: }
nuclear@2: 
nuclear@2: static int next_pow2(int x)
nuclear@2: {
nuclear@2: 	int res = 2;
nuclear@2: 	while(res < x) {
nuclear@2: 		res <<= 1;
nuclear@2: 	}
nuclear@2: 	return res;
nuclear@2: }