#include "image.h"
#include "palette.h"
#include "font.h"

#include <stdlib.h>
#include <string.h>
#include <png.h>
#include <math.h>

Image::Image() :
    iWidth( 0 ),
    iHeight( 0 ),
    pPix( NULL )
{
}

Image::Image( int32_t iWidth, int32_t iHeight ) :
    iWidth( iWidth ),
    iHeight( iHeight ),
    pPix( NULL )
{
    pPix = new uint8_t[iWidth*iHeight];
    clear();
}

Image::~Image()
{
    delete[] pPix;
}

int Image::getWidth() const
{
    return iWidth;
}

int Image::getHeight() const
{
    return iHeight;
}

void Image::clear( uint8_t uColor )
{
    memset( pPix, uColor, iWidth*iHeight );
}

void Image::set( int32_t x, int32_t y, uint8_t iCol )
{
    if( x < 0 || y < 0 || x >= iWidth || y >= iHeight )
        return;

    pPix[x+y*iWidth] = iCol;
}

void Image::save( const char *sPath, class Palette &rPal )
{
    uint8_t **pRows = new uint8_t*[iHeight];
    for( int r = 0; r < iHeight; r++ )
    {
        pRows[r] = pPix+(iWidth*r);
    }

    png_structp png_ptr = png_create_write_struct(
        PNG_LIBPNG_VER_STRING, NULL, NULL, NULL
        );
    png_infop info_ptr = png_create_info_struct(png_ptr);
    png_set_IHDR(png_ptr, info_ptr, iWidth, iHeight,
        8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
        PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT
        );
    png_color *pCol = new png_color[rPal.getCount()];
    for( int j = 0; j < rPal.getCount(); j++ )
    {
        uint8_t r, g, b;
        rPal.getColor( j, r, g, b );
        pCol[j].red = r;
        pCol[j].green = g;
        pCol[j].blue = b;
    }
    png_set_PLTE( png_ptr, info_ptr, pCol, rPal.getCount());

    png_set_rows( png_ptr, info_ptr, pRows );

    FILE *fp = fopen(sPath, "wb");
    if( fp == NULL )
    {
        printf("Error opening file!\n");
        exit( 1 );
    }
    
    png_init_io( png_ptr, fp );
    png_write_png( png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL );
    png_destroy_write_struct( &png_ptr, &info_ptr );
    fclose( fp );

    delete[] pCol;
    delete[] pRows;
}

void Image::drawText( class Font &rFnt, int32_t x, int32_t y, uint8_t uColor,
        const char *sText )
{
    for( const char *s = sText; *s; s++ )
    {
        Font::Glyph *pGlyph = rFnt.get( *s );
        if( pGlyph == NULL )
            continue;

        for( int cy = 0; cy < pGlyph->pBox.y; cy++ )
        {
            for( int cx = 0; cx < pGlyph->pBox.x; cx++ )
            {
                int bit = 1<<(7-(cx%8));
                int byte = cx/8;
                if( pGlyph->pData[byte+cy*pGlyph->iRowBytes]&bit )
                    set( x+cx, y+cy-pGlyph->pBox.y-pGlyph->pOff.y, uColor );
            }
        }
        x += pGlyph->pDevOff.x;
        y += pGlyph->pDevOff.y;
    }
}

void Image::drawLine( int32_t x1, int32_t y1, int32_t x2, int32_t y2, uint8_t uColor )
{
    if( x1 == x2 )
    {
        // Vertical line, easy
        if( y2 < y1 )
        {
            int32_t r = y2;
            y2 = y1;
            y1 = r;
        }
        for( int j = y1; j <= y2; j++ )
        {
            set( x1, j, uColor );
        }
    }
    else if( y1 == y2 )
    {
        // Horizontal line, easy
        if( x2 < x1 )
        {
            int32_t r = x2;
            x2 = x1;
            x1 = r;
        }
        for( int j = x1; j <= x2; j++ )
        {
            set( j, y1, uColor );
        }
    }
    else
    {
        int xd = x2-x1;
        int yd = y2-y1;
        float d = sqrt( xd*xd + yd*yd );
        float ux = xd/d;
        float uy = yd/d;

        float x = x1;
        float y = y1;

        set( (int)x, (int)y, uColor );
        for( float n = 0.0; n < d; n += 1.0 )
        {
            x += ux;
            y += uy;
            set( (int)x, (int)y, uColor );
        }
    }
}