/*
===========================================================
                Sony PlayStation 1 Source Code
===========================================================
                         FONT EXAMPLE
Displays text on the screen using the built in GPU routines
-----------------------------------------------------------

    Developer / Programmer..............: SCEI & PSXDEV.net
    Software Ddevelopment Kit...........: PSY-Q
    Last Updated........................: 04/MAY/2017

    Original code by SCEI | Edited by PSXDEV.net

    NOTE: This example uses double buffering.

  Copyright (C) 1994,1995 by Sony Computer Entertainment Inc.
   Sony Computer Entertainment Inc. Development Department.
                   All Rights Reserved.

                    http://psxdev.net/

-----------------------------------------------------------*/

#include <stdlib.h>
#include <libgte.h>
#include <libgpu.h>
#include <libgs.h>

#define OT_LENGTH 1 // the ordertable length
#define PACKETMAX 18 // the maximum number of objects on the screen
#define SCREEN_WIDTH  320 // screen width
#define SCREEN_HEIGHT 240 // screen height (240 NTSC, 256 PAL)

GsOT myOT[2]; // ordering table header
GsOT_TAG myOT_TAG[2][1<<OT_LENGTH]; // ordering table unit
PACKET GPUPacketArea[2][PACKETMAX]; // GPU packet data

u_long _ramsize   = 0x00200000; // force 2 megabytes of RAM
u_long _stacksize = 0x00004000; // force 16 kilobytes of stack

// --------
// INTEGERS
// --------
short CurrentBuffer = 0; // holds the current buffer number

// ----------
// PROTOTYPES
// ----------
void graphics(); // inits the GPU
void display(); // updates the GPU (IE: VRAM/SGRAM/framebuffer)

const DEBUG = 1; // debugging (1=on, 0=off)

// ---------
// FUNCTIONS
// ---------
POLY_F3 pf3;

void DrawSolidTri(short x1, short y1, short x2, short y2, short x3, short y3, int r, int g, int b, int ot)
{
    // draw a solid triangle and fill it with rgb colour
    // EG: DrawSolidTri(200,0, 170,30, 230,30, 255,0,255, 0);
    // check the Psy-Q documentation for the coordinates!

    SetPolyF3(&pf3);                            // initialise the primitive
    setRGB0(&pf3, r, g, b);                     // set the fill colour (RGB)
    setXY3(&pf3, x1,y1, x2,y2, x3,y3);          // draw 3 lines (3 sets of x/y co-ords)
    DrawPrim(&pf3);                             // copy shape to frame buffer
    //DrawPrim(&pf3);                           // copy shape to frame buffer
    GsSortPoly(&pf3, &myOT[CurrentBuffer], ot); // put the polygon into the order table
}


void DrawTransTri(short x1, short y1, short x2, short y2, short x3, short y3, int r, int g, int b, int ot)
{
    // draw a transparent triangle
    // the transparency 'colour' is calculated from the fgnd & bgns pixels.
    // EG: DrawTransTri(50,0, 70,60, 130,60, 255,0,255, 0);

    SetPolyF3(&pf3);                            // initialize primitive
    setRGB0(&pf3, r, g, b);                     // set the foreground fill colour
    setSemiTrans(&pf3, 1);                      // semi-transparency; 0=off; 1=on
    setXY3(&pf3, x1,y1, x2,y2, x3,y3);          // draw 4 lines (4 sets of x/y co-ords)
    //DrawPrim(&pf3);                           // copy shape to frame buffer
    GsSortPoly(&pf3, &myOT[CurrentBuffer], ot); // put the polygon into the order table
}

// ----
// MAIN
// ----
int main()
{
    graphics(); // setup the graphics (seen below)
    FntLoad(960, 256); // load the font from the BIOS into the framebuffer
    SetDumpFnt(FntOpen(5, 20, 320, 240, 0, 512)); // screen X,Y | max text length X,Y | autmatic background clear 0,1 | max characters

    if (DEBUG) // should debug be true (equal 1)...
    {
        // print to the TTY stream (only visible if you're using one)
        printf("\n\nHello World\n");
        printf("\nhttp://psxdev.net/");
    }

    while (1) // draw and display forever
    {
        FntPrint("             HELLO WORLD\n\n          HTTP://PSXDEV.NET/");
        DrawSolidTri(0, 0, 200, 200, 0, 300, 4, 255, 4, 0);
        display();
    }

    return 0; // this will never be reached because we're in a while loop above
}

void graphics()
{
    SetVideoMode(1); // PAL mode
    //SetVideoMode(0); // NTSC mode

    GsInitGraph(SCREEN_WIDTH, SCREEN_HEIGHT, GsINTER|GsOFSGPU, 1, 0); // set the graphics mode resolutions (GsNONINTER for NTSC, and GsINTER for PAL)
    GsDefDispBuff(0, 0, 0, SCREEN_HEIGHT); // tell the GPU to draw from the top left coordinates of the framebuffer

    // init the ordertables
    myOT[0].length = OT_LENGTH;
    myOT[1].length = OT_LENGTH;
    myOT[0].org = myOT_TAG[0];
    myOT[1].org = myOT_TAG[1];

    // clear the ordertables
    GsClearOt(0,0,&myOT[0]);
    GsClearOt(0,0,&myOT[1]);
}


void display()
{
    // refresh the font
    FntFlush(-1);

    // get the current buffer
    CurrentBuffer = GsGetActiveBuff();

    // setup the packet workbase
    GsSetWorkBase((PACKET*)GPUPacketArea[CurrentBuffer]);

    // clear the ordering table
    GsClearOt(0,0, &myOT[CurrentBuffer]);

    // wait for all drawing to finish
    DrawSync(0);

    // wait for v_blank interrupt
    VSync(0);

    // flip the double buffers
    GsSwapDispBuff();

    // clear the ordering table with a background color (R,G,B)
    GsSortClear(50,50,50, &myOT[CurrentBuffer]);

    // draw the ordering table
    GsDrawOt(&myOT[CurrentBuffer]);
}