package renderer;

import org.lwjgl.BufferUtils;

import java.nio.Buffer;

import java.nio.ByteBuffer;

import java.nio.IntBuffer;

import static org.lwjgl.opengl.GL11.*;

import static org.lwjgl.stb.STBImage.*;

public class Texture

{

private String filepath;

private int textureID;

public Texture(String filepath)

{

this.filepath = filepath;

// Generate texture on gpu

textureID = glGenTextures();

glBindTexture(GL_TEXTURE_2D, textureID);

// Set the texture parameters

// Repeat the image in both directions

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

// When stretching the image, pixelate

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

// When shrinking the image, pixelate

glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

IntBuffer width = BufferUtils.createIntBuffer(1);

IntBuffer height = BufferUtils.createIntBuffer(1);

IntBuffer channels = BufferUtils.createIntBuffer(1);

stbi_set_flip_vertically_on_load(true);

ByteBuffer image = stbi_load(filepath, width, height, channels, 0);

if (image != null)

{

if (channels.get(0) == 3)

{

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width.get(0), height.get(0), 0, GL_RGB, GL_UNSIGNED_BYTE, image);

}

else if (channels.get(0) == 4)

{

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width.get(0), height.get(0), 0, GL_RGBA, GL_UNSIGNED_BYTE, image);

}

else

{

assert false : "Error: ('TEXTURE') Unknown number of channels '" + channels.get(0) + "'";

}

}

else

{

assert false : "Error: ('TEXTURE') Could not load image '" + filepath + "'";

}

stbi_image_free(image);

}

public void bind()

{

glBindTexture(GL_TEXTURE_2D, textureID);

}

public void unbind()

{

glBindTexture(GL_TEXTURE_2D, 0);

}

}