/*---------------------------------------------------------------------------*
  Project:     KPAD sample program
  File:        graphic.c
  Programmer:  Keizo Ohta

  Copyright 2005 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 <revolution.h>
#include <math.h>

#include "graphic.h"

/***************************************************************
    Variables
***************************************************************/
GXColor black_clr    = {   0,  0,  0, 255 } ;
GXColor smoke_clr    = {  61, 61, 61, 255 } ;
GXColor gray_clr     = { 129,129,129, 255 } ;
GXColor white_clr    = { 255,255,255, 255 } ;
GXColor silver_clr   = { 193,193,193, 255 } ;
GXColor red_clr      = { 237, 28, 36, 255 } ;
GXColor green_clr    = {   0,166, 81, 255 } ;
GXColor blue_clr     = {   0, 84,166, 255 } ;
GXColor yellow_clr   = { 255,242,  0, 255 } ;
GXColor cyan_clr     = {   0,174,239, 255 } ;
GXColor magenta_clr  = { 236,  0,140, 255 } ;
GXColor orange_clr   = { 245,125, 32, 255 } ;
GXColor violet_clr   = { 102, 45,145, 255 } ;
GXColor peagreen_clr = { 141,198, 63, 255 } ;

/*******************************************************************************
    Initialize drawing of simple graphics
    fb_width  :Horizontal resolution of frame buffer
    fb_height :Vertical resolution of frame buffer
*******************************************************************************/
void init_draw_graphic( u16 fb_width, u16 fb_height )
{
    Mtx44 proj_mtx ;
    Mtx   view_mtx ;
    f32   canvas_wd, canvas_ht ;

    //----- Virtual canvas size
    canvas_wd = fb_width * 0.91346f ;
    canvas_ht = fb_height ;

    //----- MTX
    MTXOrtho( proj_mtx, canvas_ht * -0.5f,canvas_ht * 0.5f, canvas_wd * -0.5f,canvas_wd * 0.5f, -10.0f,10.0f ) ;
    GXSetProjection( proj_mtx, GX_ORTHOGRAPHIC ) ;

    MTXIdentity( view_mtx ) ;
    GXLoadPosMtxImm( view_mtx, GX_PNMTX0 ) ;
    GXSetCurrentMtx( GX_PNMTX0 ) ;

    //----- VERTEX
    GXClearVtxDesc() ;
    GXSetVtxDesc( GX_VA_POS, GX_DIRECT ) ;
    GXSetVtxAttrFmt( GX_VTXFMT0, GX_VA_POS, GX_POS_XY, GX_F32, 0 ) ;

    //----- CHANNEL
    GXSetNumChans( 1 ) ;
    GXSetChanCtrl( GX_COLOR0A0, GX_DISABLE, GX_SRC_REG, GX_SRC_REG, GX_LIGHT_NULL, GX_DF_NONE, GX_AF_NONE ) ;
    GXSetChanCtrl( GX_COLOR1A1, GX_DISABLE, GX_SRC_REG, GX_SRC_REG, GX_LIGHT_NULL, GX_DF_NONE, GX_AF_NONE ) ;

    //----- TEXTURE
    GXSetNumTexGens( 0 ) ;

    //----- TEV
    GXSetNumTevStages( 1 ) ;
    GXSetTevOrder( GX_TEVSTAGE0, GX_TEXCOORD_NULL, GX_TEXMAP_NULL, GX_COLOR_NULL ) ;
    GXSetTevColorIn( GX_TEVSTAGE0, GX_CC_ZERO, GX_CC_ZERO, GX_CC_ZERO, GX_CC_C0 ) ;
    GXSetTevColorOp( GX_TEVSTAGE0, GX_TEV_ADD, GX_TB_ZERO, GX_CS_SCALE_1, GX_ENABLE, GX_TEVPREV ) ;
    GXSetTevAlphaIn( GX_TEVSTAGE0, GX_CA_ZERO, GX_CA_ZERO, GX_CA_ZERO, GX_CA_A0 ) ;
    GXSetTevAlphaOp( GX_TEVSTAGE0, GX_TEV_ADD, GX_TB_ZERO, GX_CS_SCALE_1, GX_ENABLE, GX_TEVPREV ) ;
    GXSetAlphaCompare( GX_ALWAYS,0, GX_AOP_OR, GX_ALWAYS,0 ) ;

    //----- SCREEN
    GXSetBlendMode( GX_BM_BLEND, GX_BL_SRCALPHA, GX_BL_INVSRCALPHA, GX_LO_NOOP ) ;
    GXSetAlphaUpdate( GX_DISABLE ) ;

    GXSetZMode( GX_DISABLE, GX_ALWAYS, GX_DISABLE ) ;
    GXSetCullMode( GX_CULL_BACK ) ;
}


/*******************************************************************************
    Draw point
*******************************************************************************/
void draw_point( f32 px, f32 py, GXColor clr, f32 size )
{
    GXSetTevColor( GX_TEVREG0, clr ) ;
    GXSetPointSize( (u8)(s32)(size * 6.0f + 0.5f), GX_TO_ZERO ) ;

    GXBegin( GX_POINTS, GX_VTXFMT0, 1 ) ;
      GXPosition2f32( px, py ) ;
    GXEnd() ;
}


/*******************************************************************************
    Draw line
*******************************************************************************/
void draw_line( f32 x1, f32 y1, f32 x2, f32 y2, GXColor clr, f32 width )
{
    GXSetTevColor( GX_TEVREG0, clr ) ;
    GXSetLineWidth( (u8)(s32)(width * 6.0f + 0.5f), GX_TO_ZERO ) ;

    GXBegin( GX_LINES, GX_VTXFMT0, 2 ) ;
      GXPosition2f32( x1, y1 ) ;
      GXPosition2f32( x2, y2 ) ;
    GXEnd() ;
}


/*******************************************************************************
    Draw broken line
*******************************************************************************/
void draw_dashed_line( f32 x1, f32 y1, f32 x2, f32 y2, GXColor clr, f32 width )
{
    const int DIV=5;
    int i=0;
    f32 dx = x2 - x1;
    f32 dy = y2 - y1;
    f32 length = (f32)sqrt(dx*dx + dy*dy);
    GXSetTevColor( GX_TEVREG0, clr ) ;
    GXSetLineWidth( (u8)(s32)(width * 6.0f + 0.5f), GX_TO_ZERO ) ;

    for(i=0; i<DIV; ++i){
        GXBegin( GX_LINES, GX_VTXFMT0, 2 ) ;
          GXPosition2f32( x1+dx/(2*DIV)*(2*i+0), y1+dy/(2*DIV)*(2*i+0) ) ;
          GXPosition2f32( x1+dx/(2*DIV)*(2*i+1), y1+dy/(2*DIV)*(2*i+1) ) ;
        GXEnd() ;
    }
}


/*******************************************************************************
    Draw arrow
*******************************************************************************/
void draw_arrow( f32 x1, f32 y1, f32 x2, f32 y2, GXColor clr, f32 width )
{
    f32 vx,vy, f ;

    vx = x2 - x1 ;
    vy = y2 - y1 ;
    f = sqrtf( vx*vx + vy*vy ) ;
    if ( f == 0.0f ) {
        vx = vy = 0.0f ;
    } else {
        f = width * 2.0f / f ;
        vx *= f ;
        vy *= f ;
    }
    draw_line( x1,y1, x2,y2, clr, width ) ;
    draw_line( x2,y2, x2-vx-vx-vy,y2-vy-vy+vx, clr, width ) ;
    draw_line( x2,y2, x2-vx-vx+vy,y2-vy-vy-vx, clr, width ) ;
}


/*******************************************************************************
    Draw arrow (broken line)
*******************************************************************************/
void draw_dashed_arrow( f32 x1, f32 y1, f32 x2, f32 y2, GXColor clr, f32 width )
{
    f32 vx,vy, f ;

    vx = x2 - x1 ;
    vy = y2 - y1 ;
    f = sqrtf( vx*vx + vy*vy ) ;
    if ( f == 0.0f ) {
        vx = vy = 0.0f ;
    } else {
        f = width * 2.0f / f ;
        vx *= f ;
        vy *= f ;
    }
    draw_dashed_line( x1,y1, x2,y2, clr, width ) ;
    draw_line( x2,y2, x2-vx-vx-vy,y2-vy-vy+vx, clr, width ) ;
    draw_line( x2,y2, x2-vx-vx+vy,y2-vy-vy-vx, clr, width ) ;
}


/*******************************************************************************
    Draw circle
*******************************************************************************/
void draw_circle( f32 ox, f32 oy, f32 radius, GXColor clr, f32 width )
{
    s32 vtxs = 40 ;             // Number of vertices
    f32 k = 6.29f / (f32)vtxs ; // 2pi divided by the number of sections
    s32 n ;
    f32 f, vx,vy ;

    if ( radius < width * 0.1f ) {
        //----- Radii that are too small are handled as points
        draw_point( ox,oy, clr, width ) ;
        return ;
    }

    GXSetTevColor( GX_TEVREG0, clr ) ;
    GXSetLineWidth( (u8)(s32)(width * 6.0f + 0.5f), GX_TO_ZERO ) ;

    GXBegin( GX_LINESTRIP, GX_VTXFMT0, (u16)(vtxs + 1) ) ;

    vx = radius ;
    vy = 0.0f ;
    n = vtxs ;
    do {
        GXPosition2f32( ox + vx, oy + vy ) ;

        //----- Proceed in the direction of angular velocity
        f = vx ;
        vx -= vy * k ;
        vy +=  f * k ;

        //----- Correct radius
        f = radius / sqrtf( vx * vx + vy * vy ) ;
        vx *= f ;
        vy *= f ;
    } while ( --n != 0 ) ;

    GXPosition2f32( ox + radius, oy ) ;    // The last point is the same as the start point
    GXEnd() ;
}