texture.cpp

#include "texture.hpp"
#include "bitmap_image.hpp"
void
Texture::load(const char * filename)
{
    bimg=new bitmap_image(filename);
    height = bimg->height();
    width = bimg->width();
}

void
Texture::operator()(int x, int y,  unsigned char * color)
{
    x = clamp(x,0,width-1);
    y = clamp(y,0,height-1);
    bimg->get_pixel(x,y,color[0],color[1],color[2]);
}
bool Texture::valid()
{
    return bimg!=0;
}
///@param x assumed to be between 0 and 1
Vector3f
Texture::operator()(float x, float y)
{
    Vector3f color;
    int ix,iy;
    x=x*width;
    y=(1-y)*height;
    ix = (int)x;
    iy = (int)y;
    unsigned char pixels[4][3];
    float alpha = x-ix;
    float beta = y-iy;
    operator()(ix,iy,pixels[0]);
    operator()(ix+1,iy,pixels[1]);
    operator()(ix,iy+1,pixels[2]);
    operator()(ix+1,iy+1,pixels[3]);
    for(int ii=0; ii<3; ii++) {
        color[ii] = (1-alpha)*(1-beta)*pixels[0][ii]
                    +    alpha *(1-beta)*pixels[1][ii]
                    + (1-alpha)*   beta *pixels[2][ii]
                    +    alpha *   beta *pixels[3][ii];
    }
    return color/255;
}

Texture::~Texture()
{
    if(bimg!=0) {
        delete bimg;
    }
}

Texture::Texture() : bimg(0),width(0),height(0)
{
}