cloudy-raytracer/common/texture.cpp

95 lines
2.8 KiB
C++

#include "common/texture.h"
#include <cmath>
#include <fstream>
#include <iostream>
#include <string>
#include <utility>
Texture::Texture(int width, int height) { this->resize(width, height); }
Texture::Texture(char const *fileName) { this->load(fileName); }
bool Texture::load(char const *fileName) {
CImg<unsigned char> img_char(fileName);
if (img_char.is_empty()) {
std::cerr << "(Image): Could not open file " << fileName << std::endl;
return false;
}
this->image_ = CImg<float>(img_char.width(), img_char.height(), img_char.depth(), 3, 0);
for (int c = 0; c < 3; c++)
cimg_forXYZ(img_char, x, y, z) {
this->image_(x, y, z, c) = img_char(x, y, z, std::min(c, img_char.spectrum() - 1)) / 255.0f;
}
return true;
}
bool Texture::save(char const *fileName) const {
CImg<unsigned char> img_char;
img_char = 255 * this->image_;
img_char.save(fileName);
return true;
}
Color Texture::getPixelAt(int x, int y) const {
if ((x %= this->width()) < 0)
x += this->width();
if ((y %= this->height()) < 0)
y += this->height();
return Color(this->image_.atXY(x, y, 0), this->image_.atXY(x, y, 1), this->image_.atXY(x, y, 2));
}
void Texture::setPixelAt(int x, int y, Color const &color) {
if ((x %= this->width()) < 0)
x += this->width();
if ((y %= this->height()) < 0)
y += this->height();
this->image_(x, y, 0) = color.r;
this->image_(x, y, 1) = color.g;
this->image_(x, y, 2) = color.b;
}
Color Texture::color(float u, float v, bool interpolate) const {
Color color;
if (!interpolate) {
color = this->getPixelAt(int(roundf(u * this->width())), int(roundf(v * this->height())));
} else {
// bilinear interpolation
// adjacent pixel coordinates
int left = int(floorf(u * this->width()));
int right = int(ceilf(u * this->width()));
int top = int(floorf(v * this->height()));
int bottom = int(ceilf(v * this->height()));
// weights
float w[4];
w[0] = right - u * this->width();
w[1] = 1 - w[0];
w[2] = bottom - v * this->height();
w[3] = 1 - w[2];
// get color values and interpolate
Color val[4];
val[0] = this->getPixelAt(left, top);
val[1] = this->getPixelAt(right, top);
val[2] = this->getPixelAt(left, bottom);
val[3] = this->getPixelAt(right, bottom);
color = w[2] * w[0] * val[0] + w[2] * w[1] * val[1] + w[3] * w[0] * val[2] + w[3] * w[1] * val[3];
}
return color;
}
Color Texture::color(Vector2d const &surfacePosition, bool interpolate) const {
return color(surfacePosition.u, surfacePosition.v, interpolate);
}
CImg<float>& Texture::getImage() {
return image_;
}
void Texture::setTexture(CImg<float> image){
image_ = std::move(image);
}