/* 
 * LibPSn00b Example Programs
 *
 * Text Console Example
 * 2020 - 2021 Meido-Tek Productions / PSn00bSDK Project
 *
 * This example demonstrates a tty text console implementation for gameplay 
 * sections, or sections with continuously updating graphics. The console is
 * brought up by the tilde key in which, execution of the gameplay section would
 * get paused until the console is exited. A fully asynchronous implementation
 * should be possible, but this is beyond the scope of this simple example.
 *
 *
 * Example by Lameguy64
 *
 * Changelog:
 *
 *	May 10, 2021		- Variable types updated for psxgpu.h changes.
 *
 *  April 23, 2020		- Initial version.
 *
 */

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <psxapi.h>
#include <psxetc.h>
#include <psxgte.h>
#include <psxgpu.h>
#include <psxsio.h>

#define MAX_BALLS 1024

#define OT_LEN 		8

#define SCREEN_XRES	640
#define SCREEN_YRES	480

#define CENTER_X	SCREEN_XRES/2
#define CENTER_Y	SCREEN_YRES/2


/* Display and drawing environments */
DISPENV disp;
DRAWENV draw;

char pribuff[2][65536];		/* Primitive packet buffers */
uint32_t ot[2][OT_LEN];		/* Ordering tables */
char *nextpri;				/* Pointer to next packet buffer offset */
int db = 0;					/* Double buffer index */


/* Ball struct and array */
typedef struct {
	short x,y;
	short xdir,ydir;
	unsigned char r,g,b,p;
} BALL_TYPE;

BALL_TYPE balls[MAX_BALLS];

/* Ball texture reference */
extern const uint32_t ball16c[];

/* TIM image parameters for loading the ball texture and drawing sprites */
TIM_IMAGE tim;


void init() {
	
	int i;
	
	/* Reset GPU (also installs event handler for VSync) */
	printf("Init GPU... ");
	ResetGraph( 0 );
	printf("Done.\n");
	
	
	printf("Set video mode... ");
	
	/* Set display and draw environment parameters */
	SetDefDispEnv( &disp, 0, 0, SCREEN_XRES, SCREEN_YRES );
	SetDefDrawEnv( &draw, 0, 0, SCREEN_XRES, SCREEN_YRES );
	disp.isinter = 1; /* Enable interlace (required for hires) */
	
	/* Set clear color, area clear and dither processing */
	setRGB0( &draw, 63, 0, 127 );
	draw.isbg = 1;
	draw.dtd = 1;
	
	/* Apply the display and drawing environments */
	PutDispEnv( &disp );
	PutDrawEnv( &draw );
	
	/* Enable video output */
	SetDispMask( 1 );
	
	printf("Done.\n");
	
	
	/* Upload the ball texture */
	printf("Upload texture... ");
	GetTimInfo( ball16c, &tim ); /* Get TIM parameters */
	
	LoadImage( tim.prect, tim.paddr );		/* Upload texture to VRAM */
	if( tim.mode & 0x8 ) {
		LoadImage( tim.crect, tim.caddr );	/* Upload CLUT if present */
	}
	
	printf("Done.\n");
	
	
	/* Calculate ball positions */
	printf("Calculating balls... ");
	
	for( i=0; i<MAX_BALLS; i++ )
	{
		balls[i].x = (rand()%624);
		balls[i].y = (rand()%464);
		balls[i].xdir = 1-(rand()%3);
		balls[i].ydir = 1-(rand()%3);
		if( !balls[i].xdir ) balls[i].xdir = 1;
		if( !balls[i].ydir ) balls[i].ydir = 1;
		balls[i].xdir *= 2;
		balls[i].ydir *= 2;
		balls[i].r = (rand()%256);
		balls[i].g = (rand()%256);
		balls[i].b = (rand()%256);
	}
	
	printf("Done.\n");
	
}


void do_console(void)
{
	char line[32];
	
	/* Print console banner */
	printf("\nConsole mode! Enter 'exit' to return to gameplay.\n");
	
	/* The parser loop */
	while(1)
	{
		/* Print a prompt character and read a line of input */
		putchar('>');
		gets(line);
		
		/* Exit the parser if the text entered is exit */
		if( strcmp(line, "exit") == 0 )
			break;
			
		/* Print the input */
		printf("You entered: %s\n", line);
	}
}


int main(int argc, const char* argv[]) {
	
	SPRT_16 *sprt;
	DR_TPAGE *tpri;
	
	int i,counter=0;
	
	
	/* Init graphics and stuff before doing anything else */
	init();
	
	
	/* Uncomment this line if you don't have tty interfaces
	 * provided by n00brom or similar development environments with tty */
	//AddSIO(115200);
	
	
	/* Main loop */
	printf("Entering loop...\n");
	
	while(1)
	{
		/* FIOCSCAN will return a non-zero value when there's 
		 * input pending in tty, file handle 0 is usually stdin */
		if( ioctl(0, FIOCSCAN, 0) )
		{
			/* Get the character */
			i = getchar();
			
			/* If the key that's pressed is a tilde, enter the console */
			if( i == '`' )
				do_console();
		}
		
		/* Clear ordering table and set start address of primitive
		 * buffer for next frame */
		ClearOTagR(ot[db], OT_LEN);
		nextpri = pribuff[db];
		
		/* Sort a balls snake */
		sprt = (SPRT_16*)nextpri;
		srand(64);
		for( i=0; i<32; i++ )
		{
			setSprt16(sprt);
			setXY0(sprt, 
				(CENTER_X-8)+(isin((counter-(i<<4))<<3)>>5), 
				(CENTER_Y-8)-(icos((counter-(i<<2))<<3)>>5));
			setRGB0(sprt, rand()%256, rand()%256, rand()%256);
			setUV0(sprt, 0, 0);
			setClut(sprt, tim.crect->x, tim.crect->y);
			
			addPrim(ot[db]+(OT_LEN-1), sprt);
			sprt++;
		
		}
		
		/* Sort the balls */
		for( i=0; i<MAX_BALLS; i++ )
		{	
			setSprt16(sprt);
			setXY0(sprt, balls[i].x, balls[i].y);
			setRGB0(sprt, balls[i].r, balls[i].g, balls[i].b);
			setUV0(sprt, 0, 0 );
			setClut(sprt, tim.crect->x, tim.crect->y);
			
			addPrim(ot[db]+(OT_LEN-1), sprt);
			sprt++;
			
			balls[i].x += balls[i].xdir;
			balls[i].y += balls[i].ydir;
			
			if( ( balls[i].x+16 ) > 640 )
			{
				balls[i].xdir = -2;
			}
			else if( balls[i].x < 0 )
			{
				balls[i].xdir = 2;
			}
			
			if( ( balls[i].y+16 ) > 480 )
			{
				balls[i].ydir = -2;
			}
			else if( balls[i].y < 0 )
			{
				balls[i].ydir = 2;
			}
			
		}
		
		nextpri = (char*)sprt;
		
		
		/* Sort a TPage primitive so the sprites will draw pixels from
		 * the correct texture page in VRAM */
		tpri = (DR_TPAGE*)nextpri;
		setDrawTPage(tpri, 0, 0, 
			getTPage(0, 0, tim.prect->x, tim.prect->y));
		addPrim(ot[db]+(OT_LEN-1), tpri);
		nextpri += sizeof(DR_TPAGE);
		
		/* Wait for GPU and VSync */
		DrawSync(0);
		VSync(0);
		
		/* Since draw.isbg is non-zero this clears the screen */
		PutDrawEnv(&draw);
		
		/* Begin drawing the new frame */
		DrawOTag(ot[db]+(OT_LEN-1));
		
		/* Alternate to the next buffer */
		db = !db;
		
		/* Increment counter for the snake animation */
		counter++;
		
	}
		
	return 0;

}