/*---------------------------------------------------------------------------*
  Project:  Dolphin/Revolution gx demo
  File:     smp-texexample.c

  Copyright 1998-2006 Nintendo.  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law.  They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.
 *---------------------------------------------------------------------------*/

#include <demo.h>

#define BALL64_TEX_ID        8

/*---------------------------------------------------------------------------*
  Model Data
 *---------------------------------------------------------------------------*/

static s8 Vert_s8[] ATTRIBUTE_ALIGN(32) = 
{        
    -100,  100, 0,  // 0
     100,  100, 0,  // 1
    -100, -100, 0   // 2
};        
                                  
static u32 Colors_u32[] ATTRIBUTE_ALIGN(32) = 
{         
//    r g b a
    0xff0000ff, // 0
    0x00ff00ff, // 1
    0x0000ffff  // 2
};                          

//  Array of texture coordinates
static u8 TexCoords_u8[] ATTRIBUTE_ALIGN(32) = 
{        
    0x00, 0x00, // 0
//    s     t        fixed point format is unsigned 8.0
    0x01, 0x00, // 1
    0x00, 0x01  // 2
};

/*---------------------------------------------------------------------------*
   Forward references
 *---------------------------------------------------------------------------*/
                  
static void CameraInit( Mtx v );

/*---------------------------------------------------------------------------*
   Application main loop
 *---------------------------------------------------------------------------*/

void main ( void )
{   
    PADStatus     pad[4];  // game pad state
    GXTexObj      texObj;  // texture object
    Mtx           v;       // view matrix
    u8            i;       // loop variable
    TPLPalettePtr tpl = 0; // texture palette
    
    pad[0].button = 0;

    DEMOInit(NULL);    // Init os, pad, gx, vi

    CameraInit(v);
    GXLoadPosMtxImm(v, GX_PNMTX0);

    GXSetNumChans(1);  // Enable light channel; by default = vertex color

    GXClearVtxDesc();
    GXSetVtxDesc(GX_VA_POS,  GX_INDEX8);
    GXSetVtxDesc(GX_VA_CLR0, GX_INDEX8);
    // Add an indexed texture coordinate to the vertex description
    GXSetVtxDesc(GX_VA_TEX0, GX_INDEX8);

    GXSetArray(GX_VA_POS,  Vert_s8, 3*sizeof(s8));
    GXSetArray(GX_VA_CLR0, Colors_u32, 1*sizeof(u32));
    GXSetArray(GX_VA_TEX0, TexCoords_u8, 2*sizeof(u8));

    GXSetVtxAttrFmt(GX_VTXFMT0, GX_VA_POS,  GX_POS_XYZ,  GX_S8,    0);
    GXSetVtxAttrFmt(GX_VTXFMT0, GX_VA_CLR0, GX_CLR_RGBA, GX_RGBA8, 0);
    //  Describe the texture coordinate format
    //  fixed point format is unsigned 8.0
    GXSetVtxAttrFmt(GX_VTXFMT0, GX_VA_TEX0, GX_TEX_ST,   GX_U8,    0);
    
    //  Load the texture palette
    TPLGetPalette(&tpl, "gxTextrs.tpl");
    //  Initialize a texture object to contain the correct texture
    TPLGetGXTexObjFromPalette(tpl, &texObj, BALL64_TEX_ID);
    //  Load the texture object; tex0 is used in stage 0
    GXLoadTexObj(&texObj, GX_TEXMAP0);

    //  Set the Texture Environment (Tev) Mode for stage 0
    //  GXInit sets default of 1 TexCoordGen
    //  Default TexCoordGen is texcoord(n) from tex(n) with 2x4 identity mtx
    //  Default number of tev stages is 1
    //  Default stage0 uses texcoord0, texmap0, color0a0
    //  Only need to change the tevop
    GXSetTevOp(GX_TEVSTAGE0, GX_DECAL);
    
    OSReport("\n\n********************************\n");
    OSReport("to quit:\n");
    OSReport("     hit the start button\n");
    OSReport("********************************\n");
    
    while(!(pad[0].button & PAD_BUTTON_MENU))
    {
        DEMOBeforeRender();
        // Draw a triangle
        GXBegin(GX_TRIANGLES, GX_VTXFMT0, 3);
        for (i = 0; i < 3; i++) {
            GXPosition1x8(i);
            GXColor1x8(i);
            // Add texture coordinate
            GXTexCoord1x8(i);
        }
        GXEnd();
        DEMODoneRender();
        PADRead(pad);
    }
    
    OSHalt("End of demo");
}

/*---------------------------------------------------------------------------*
   Functions
 *---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*
    Name:           CameraInit
    
    Description:    Initialize the projection matrix and load into hardware.
                    Initialize the view matrix
                    
    Arguments:      v    view matrix
    
    Returns:        none
 *---------------------------------------------------------------------------*/

static void CameraInit ( Mtx v )
{
    Mtx44 p;
    Vec   camPt = {0.0F, 0.0F, 800.0F};
    Vec   at    = {0.0F, 0.0F, -100.0F};
    Vec   up    = {0.0F, 1.0F, 0.0F};

    MTXFrustum(p, 240.0F,-240.0F,-320.0F, 320.0F, 500, 2000);
    GXSetProjection(p, GX_PERSPECTIVE);
    MTXLookAt(v, &camPt, &up, &at);        
}