/**
 * @file main.c
 * @author giomba@glgprograms.it
 * @brief
 *
 * @copyright Copyright Retrofficina GLG Programs (c) 2022
 *
 */

#include "hardware/clocks.h"

#include "hardware/pll.h"
#include "pico/stdlib.h"

#include <stdint.h>
#include <stdio.h>
#include <math.h>
#include <stdlib.h>

#include "draw_demo.h"
#include "framebuffer.h"
#include "vga.h"

void setup_clocks(void)
{
	// disable resuscitation clock
	clocks_hw->resus.ctrl = 0;

	// before changing PLL, switch sys and ref cleanly away from their aux sources
	hw_clear_bits(&clocks_hw->clk[clk_sys].ctrl, CLOCKS_CLK_SYS_CTRL_SRC_BITS);
	while (clocks_hw->clk[clk_sys].selected != 0x1)
		tight_loop_contents();
	hw_clear_bits(&clocks_hw->clk[clk_ref].ctrl, CLOCKS_CLK_REF_CTRL_SRC_BITS);
	while (clocks_hw->clk[clk_ref].selected != 0x1)
		tight_loop_contents();

	// set PLL at 126 MHz, and wait for it to stabilize
	pll_init(pll_sys, 1, 1512 * MHZ, 6, 2);

	// re-configure sys_clk to use PLL
	clock_configure(clk_sys, CLOCKS_CLK_SYS_CTRL_SRC_VALUE_CLKSRC_CLK_SYS_AUX,
	                CLOCKS_CLK_SYS_CTRL_AUXSRC_VALUE_CLKSRC_PLL_SYS, 126 * MHZ, 126 * MHZ);

	// re-configure CLK PERI = clk_sys
	clock_configure(clk_peri, 0, CLOCKS_CLK_PERI_CTRL_AUXSRC_VALUE_CLK_SYS, 126 * MHZ, 126 * MHZ);
}

int main()
{
	setup_clocks();
	stdio_init_all();

	draw_demo();

	vga_machines_init();

	for (;;)
	{
		// moving sine
		const uint16_t fc = frame_counter;
		const uint16_t x = fc % 640;
		const uint16_t y = 380 + 100 * (abs(320 - x) / 640.0) * sin((fc % 640) / 12.738);

		set_pixel(x, y);

		// 13 ms <=> 75 Hz
		// Actually, there is a point in going in sync with vertical refresh,
		// but let's just forget this for the demo.
		sleep_ms(13);

		clear_pixel(x, y);
	}
}