raytracing/Texture.cpp

#include "Texture.h"
#include "util.h"

TextureRGB::TextureRGB()
{
	mImageFileContent = nullptr;
	mRGBPixel = nullptr;
	mWidth = 0;
	mHeight = 0;
}

TextureRGB::~TextureRGB()
{
	if (mImageFileContent) {
		delete[] mImageFileContent;
	}
}

void TextureRGB::Set(const char * image_path)
{
	int file_size = 0;
	mImageFileContent = LoadFileContent(image_path, file_size);
	mRGBPixel = DecodeBMP(mImageFileContent, mWidth, mHeight);
}

Vector3 TextureRGB::Sample(float u, float v)
{
	int x = int(u * mWidth);
	int y = int(u * mHeight);
	x = x < 0 ? 0 : x;
	y = y < 0 ? 0 : y;
	x = x > (mWidth - 1) ? (mWidth - 1) : x;
	y = y > (mHeight - 1) ? (mHeight - 1) : y;
	int pixel_data_start_index = 3 * (x + y * mWidth);
	float r = float(mRGBPixel[pixel_data_start_index]) / 255.0f;
	float g = float(mRGBPixel[pixel_data_start_index + 1]) / 255.0f;
	float b = float(mRGBPixel[pixel_data_start_index + 2]) / 255.0f;
	return Vector3(r, g, b);
}