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

#include "render_cpu.h"
#define HAVE_STRUCT_TIMESPEC

void idle_cpu_dummy(void)
{
//	glBindTexture(GL_TEXTURE_2D, config_cpu->tex);
//	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, config_cpu->width,
//			config_cpu->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, config_cpu->arr);
//	glBindTexture(GL_TEXTURE_2D, 0);
	glutPostRedisplay();
}

void init_cpu(config_t *config)
{
	config_cpu = config;
	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;

	calculate(x_min, y_min, x_max, y_max, config_cpu->set_func, config_cpu->arr);
	t_old_cpu = glutGet(GLUT_ELAPSED_TIME);
}

void render_cpu(void)
{
	glBindTexture(GL_TEXTURE_2D, config_cpu->tex);
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, config_cpu->width,
				config_cpu->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, config_cpu->arr);
		glBindTexture(GL_TEXTURE_2D, 0);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glBindTexture(GL_TEXTURE_2D, config_cpu->tex);
	glEnable(GL_TEXTURE_2D);

	glBegin(GL_QUADS);
	    glTexCoord2i(0, 0); glVertex2i(0, 0);
	    glTexCoord2i(0, 1); glVertex2i(0, config_cpu->height);
	    glTexCoord2i(1, 1); glVertex2i(config_cpu->width, config_cpu->height);
	    glTexCoord2i(1, 0); glVertex2i(config_cpu->width, 0);
	glEnd();

	glDisable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, 0);
	glutSwapBuffers();
}

void calculate(d64 x_min, d64 y_min, d64 x_max, d64 y_max, u32 (*sfunc) (d64, d64, u32), u32 *arr)
{
	pthread_t thread;
	ThreadArgs *args = (ThreadArgs *) malloc(config_cpu->config_cpu.threads * sizeof(ThreadArgs));
	for(u8 i = 0; i < config_cpu->config_cpu.threads; i++)
	{
		args[i] = (ThreadArgs) { .tc = config_cpu->config_cpu.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);
	free(args);
}

void calculate_t(void *args)
{
	ThreadArgs *_args = (ThreadArgs *)args;
	d64 x_math, y_math;
	u32 iterations;
	for (u32 y = (config_cpu->height/_args->tc)*(_args->tid); y < config_cpu->height; y++)
	{
		for (u32 x = 0; x < config_cpu->width; x++)
		{
			x_math = _args->x_min + ((d64) x * (_args->x_max - _args->x_min)) / config_cpu->width;
			y_math = _args->y_min + ((d64) (config_cpu->height - y) * (_args->y_max - _args->y_min)) / config_cpu->height;
			iterations = _args->sfunc(x_math, y_math, config_cpu->iterations);
//			color[2].s0 = ((1.0f + native_cos(c)) * 0.5f) * 255;
//			color[2].s1 = ((1.0f + native_cos(2.0f * c + 2.0f * 3.1416f / 3.0f)) * 0.5f) * 255;
//			color[2].s2 = ((1.0f + native_cos(c - 2.0f * 3.1416f / 3.0f)) * 0.5f) * 255;
			_args->arr[COORDS(x, y, config_cpu->width)] = (((1<<24)-1)*iterations)/config_cpu->iterations;
		}
	}
}

void idle_cpu(void)
{
	int t = 0, delta = 0;
	do
	{
		t = glutGet(GLUT_ELAPSED_TIME);
		delta = t - t_old_cpu;
	}
	while(delta < 16); // TODO: Hardcoded FPS
	t_old_cpu = t;

	calculate(x_min, y_min, x_max, y_max, config_cpu->set_func, config_cpu->arr);
	//glGenTextures(1, &tex);
	glBindTexture(GL_TEXTURE_2D, config_cpu->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_cpu->width, config_cpu->height, 0, GL_RGBA, GL_UNSIGNED_BYTE, config_cpu->arr);
	glBindTexture(GL_TEXTURE_2D, 0);
	ft+=(config_cpu->speed*(delta/1000.0));
	x_min = x_min_s + config_cpu->zoom_func(ft, (d64)2.0 + config_cpu->to_x);
	y_min = y_min_s + config_cpu->zoom_func(ft, (d64)1.0 + config_cpu->to_y);
	x_max = x_max_s - config_cpu->zoom_func(ft, (d64)1.0 - config_cpu->to_x);
	y_max = y_max_s - config_cpu->zoom_func(ft, (d64)1.0 - config_cpu->to_y);
	glutPostRedisplay();
}

void keyboard_cpu(unsigned char key, int mouseX, int mouseY)
{
	switch(key)
	{
	case 'i':
		config_cpu->iterations++;
		break;
	case 'd':
		config_cpu->iterations--;
		break;
	}
}

void mouse_cpu(int button, int state, int x, int y)
{
	if (state == GLUT_DOWN)
	{
		switch (button)
		{
		case GLUT_LEFT_BUTTON:
			if (config_cpu->speed < 0)
				config_cpu->speed = (-1) * config_cpu->speed;
			break;
		case GLUT_RIGHT_BUTTON:
			if (config_cpu->speed > 0)
				config_cpu->speed = (-1) * config_cpu->speed;
			break;
		}
		config_cpu->to_x = x_min
				+ ((d64) x * (x_max - x_min)) / config_cpu->width;
		config_cpu->to_y = y_min
				+ ((d64) y * (y_max - y_min)) / config_cpu->height;
		t_old_cpu = glutGet(GLUT_ELAPSED_TIME);
		glutIdleFunc(idle_cpu);
	}
	else if (state == GLUT_UP)
	{
		glutIdleFunc(idle_cpu_dummy);
	}
}