/*
 * render.c
 *
 *  Created on: 15.01.2018
 *      Author: Superleo1810
 */

#include "render.h"
#define HAVE_STRUCT_TIMESPEC
#include <pthread.h>

void render_init(Config *config, u32 (*sfunc) (long double, long double, u32))
{
	delta = glutGet(GLUT_ELAPSED_TIME);
	x_min_s = -2.0;
	x_max_s = 1.0;
	y_min_s= -1.0;
	y_max_s = 1.0;
	x_min = x_min_s;
	x_max = x_max_s;
	y_min = y_min_s;
	y_max = y_max_s;
	_config = config;
	_sfunc = sfunc;
	s_arr = (u32 *) malloc((_config->width) * (_config->height) * sizeof(u32));
	calculate(x_min, y_min, x_max, y_max, _sfunc, s_arr);
	//glutInit(0, NULL);
	glutInitWindowPosition(0, 0);
	glutInitWindowSize(_config->width, _config->height);
	glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
	glutCreateWindow("Renderer");
	glutDisplayFunc(gl_render);
	glutIdleFunc(gl_idle);

	glGenTextures(1, &tex);
	glBindTexture(GL_TEXTURE_2D, tex);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, _config->width, _config->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, s_arr);
	glBindTexture(GL_TEXTURE_2D, 0);
	//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, _config->width, _config->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, s_arr);

	glMatrixMode(GL_PROJECTION);
	glOrtho(0, _config->width, 0, _config->height, -1, 1);
	glMatrixMode(GL_MODELVIEW);
	glutMainLoop();
}

void render_show()
{

}

void gl_render(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glBindTexture(GL_TEXTURE_2D, tex);
	    glEnable(GL_TEXTURE_2D);
	    glBegin(GL_QUADS);
	    glTexCoord2i(0, 0); glVertex2i(0, 0);
	    glTexCoord2i(0, 1); glVertex2i(0, _config->height);
	    glTexCoord2i(1, 1); glVertex2i(_config->width, _config->height);
	    glTexCoord2i(1, 0); glVertex2i(_config->width, 0);
	    glEnd();
	    glDisable(GL_TEXTURE_2D);
	    glBindTexture(GL_TEXTURE_2D, 0);

//	glBegin(GL_TRIANGLES);
//		glVertex3f(-0.5,-0.5,0.0);
//		glVertex3f(0.5,0.0,0.0);
//		glVertex3f(0.0,0.5,0.0);
//	glEnd();

	glutSwapBuffers();
}

void calculate(long double x_min, long double y_min, long double x_max, long double y_max, u32 (*sfunc) (long double, long double, u32), u32 *arr)
{
	pthread_t thread;
	ThreadArgs *args = (ThreadArgs *) malloc(_config->threads * sizeof(ThreadArgs));
	for(u8 i = 0; i < _config->threads; i++)
	{
		args[i] = (ThreadArgs) { .tc = _config->threads, .tid = i, .x_min = x_min, .y_min = y_min, .x_max = x_max, .y_max = y_max, .sfunc = sfunc, .arr = arr };
		pthread_create(&thread, NULL, calculate_t, (void *)&args[i]);
	}
	pthread_join(thread, NULL);
}

void calculate_t(void *args)
{
	ThreadArgs *_args = (ThreadArgs *)args;
	long double x_math, y_math;
	u32 iterations;
	for (u32 y = (_config->height/_args->tc)*(_args->tid); y < _config->height; y++)
	{
		for (u32 x = 0; x < _config->width; x++)
		{
			x_math = _args->x_min + ((long double) x * (_args->x_max - _args->x_min)) / _config->width;
			y_math = _args->y_min + ((long double) (_config->height - y) * (_args->y_max - _args->y_min)) / _config->height;
			iterations = _args->sfunc(x_math, y_math, _config->iterations);
			_args->arr[COORDS(x, y, _config->width)] = (((1<<24)-1)*iterations)/_config->iterations;
		}
	}
}

long double zoom_func(long double ft, long double s)
{
	return (s - expl(-ft));
}

void gl_idle(void)
{
	calculate(x_min, y_min, x_max, y_max, _sfunc, s_arr);
	//glGenTextures(1, &tex);
	glBindTexture(GL_TEXTURE_2D, tex);
	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, _config->width, _config->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, s_arr);
	glBindTexture(GL_TEXTURE_2D, 0);
	int t = glutGet(GLUT_ELAPSED_TIME);
	dt = (t - delta) / 1000.0;
	delta = t;
	ft+=(0.1*dt);
	x_min = x_min_s + zoom_func(ft, (long double)2.0 + _config->to_x);
	y_min = y_min_s + zoom_func(ft, (long double)1.0 + _config->to_y);
	x_max = x_max_s - zoom_func(ft, (long double)1.0 - _config->to_x);
	y_max = y_max_s - zoom_func(ft, (long double)1.0 - _config->to_y);
	glutPostRedisplay();
}