/****************************************************************************
 * RAGE128 Chapter 6 Sample Code                                            *
 *                                                                          *
 * ringfan.c - This program demonstrates how to draw a 3D triangle fan      *
 * using the 3D_RNDR_GEN_PRIM Type-3 command packet. Vertex data is copied  *
 * into the ring buffer as part of the packet.                              *
 *                                                                          *
 * Copyright (c) 1999 ATI Technologies Inc.  All rights reserved.           *
 ****************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <i86.h>
#include <conio.h>
#include <math.h>
#include "..\..\util\regdef.h"
#include "..\..\util\defines.h"
#include "..\..\util\main.h"
#include "..\..\util\cce.h"
#include "..\util\cntx3d.h"
#include "..\util\prim.h"

#define NUM_TRIS 40
#define PI_X_2 6.28319f

char gErrMsg [64] = {0};

extern DWORD BPPOverride; // Override default 8bpp mode in Chap 3 lib.


/****************************************************************************
 * main                                                                     *
 *  Function: Main loop.                                                    *
 *    Inputs: none                                                          *
 *   Outputs: none                                                          *
 ****************************************************************************/

void main (int argc, char *argv[])
{
	int i, exitcode = 0;
    PRIMDATA trifan;
    float centerx, centery, radius, angle, deltaangle, sinval, cosval; 

    printf ("Rage 128 Sample Code, Chapter 6.\n"
        "RINGFAN.EXE\n\n"
        "This program demonstrates how to draw a triangle fan using the\n"
        "3D_RNDR_GEN_PRIM CCE Type-3 command packet. Vertex data is copied\n"
        "into the ring buffer as part of the packet.\n\n"
        "Mode resolution (eg 640 480) and colour depth (15, 16, 32)\n"
        "should be passed as command line arguments.\n"
        "Default resolution and colour depth is 640x480, 32bpp.\n\n"
        "Press any key to continue.\n\n");

    getch ();

    // Inspect arguments for invalid color depth.

    for (i = 1; i < argc; i++)
    {
        if ((strcmp (argv[i], "8") == 0) || (strcmp (argv[i], "24") == 0))
		{
			printf ("\nThis program does not operate at 8 or 24 bpp.");
			printf ("\nProgram terminated.");
			exit (1);
		}
	}

    // Override default 8bpp mode in Chap 3 lib.

    BPPOverride = 32;

    // First, run StartUp function to set up the application.

    R128_StartUp (argc, argv);

    // Clear the screen.

    R128_ClearScreen (DARKBLUE);

    // Initialize the CCE microengine.

    if (R128_CCEInit (CCE_MODE_192BM) != CCE_SUCCESS)
    {
        R128_ShutDown ();
        printf ("R128_CCEInit failed!!\n");
        exit (1);
    } // if

	// Set the default 3D context.

    R128_Init3DContext ();

    // Create a triangle fan.

    trifan.verts = (LPTLVERTEX2) malloc ((NUM_TRIS + 2) * sizeof (TLVERTEX2));
    if (trifan.verts == NULL)
    {
        sprintf (gErrMsg, "trifan malloc failed!!");
        exitcode = 1;
		goto exit_app;
    }

    trifan.numverts = NUM_TRIS + 2;

    // Compute triangle position and size paramters.

	centerx = R128_AdapterInfo.xres/2.0f;
	centery = R128_AdapterInfo.yres/2.0f; 
	radius = (centery * 0.9f); 
	angle = 0.0f;
	deltaangle = PI_X_2/(float) NUM_TRIS;

    // Set the center vertex.

    trifan.verts[0].x = centerx;
    trifan.verts[0].y = centery;
    trifan.verts[0].z = 0.5f;
    trifan.verts[0].rhw = 1.0f;
    trifan.verts[0].specular = 0x00000000;
	trifan.verts[0].diffuse = 0x00000000;
	trifan.verts[0].s2 = trifan.verts[0].s1 = 0.5f;
	trifan.verts[0].t2 = trifan.verts[0].t1 = 0.5f;

    // Set the perimiter vertices.

    for (i=1; i < trifan.numverts; i++)
    {
		sinval = (float)sin ((double)angle);
		cosval = (float)cos ((double)angle);
		trifan.verts[i].x = centerx + (sinval * radius);
		trifan.verts[i].y = centery - (cosval * radius);
		trifan.verts[i].z = 0.5f;
		trifan.verts[i].rhw = 1.0f;
		trifan.verts[i].specular = 0x00000000;
		trifan.verts[i].diffuse = 0x00ffffff;
		trifan.verts[i].s2 = trifan.verts[i].s1 = 0.5f + (sinval * 0.5f);
		trifan.verts[i].t2 = trifan.verts[i].t1 = 0.5f + (cosval * 0.5f);
		angle += deltaangle;
    }

    // Draw the triangle fan.

    ATTEMPT (R128_DrawTriangleFan (&trifan),
        "DrawTriFan failed!!")

	// Wait for key press to exit.

    getch ();

exit_app:

    // Free the vertex buffer.

	if (trifan.verts)
		free (trifan.verts);

	// Close 3D context, shut down micro-engine and restore original mode.

	R128_Close3DContext ();
    R128_CCEEnd (CCE_END_WAIT);
    R128_ShutDown ();

	// print error message if any.

	if (exitcode == 1)
		printf ("%s\n", gErrMsg);

	exit (exitcode);
} // main

