main.io.github.seba244c.icespire.graphics.Texture Maven / Gradle / Ivy

package io.github.seba244c.icespire.graphics;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
import org.lwjgl.system.MemoryStack;

import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL30.glGenerateMipmap;
import static org.lwjgl.stb.STBImage.stbi_load;
import static org.lwjgl.stb.STBImage.stbi_failure_reason;
import static org.lwjgl.stb.STBImage.stbi_image_free;
import static org.lwjgl.stb.STBImage.stbi_load_from_memory;

/**
 * A texture is a image can be applied to an material. Requires an image.
 * @author Sebsa
 * @since 1.0.2
 */
public class Texture {
    private final int id;
    private final int width;
    private final int height;
    public ByteBuffer imageBuffer;

    public Texture(String fileName) throws Exception {
        // Load Texture file
        try (MemoryStack stack = MemoryStack.stackPush()) {
            IntBuffer w = stack.mallocInt(1);
            IntBuffer h = stack.mallocInt(1);
            IntBuffer channels = stack.mallocInt(1);

            imageBuffer = stbi_load(fileName, w, h, channels, 4);
            if (imageBuffer == null) {
                throw new IOException("Image file [" + fileName  + "] not loaded: " + stbi_failure_reason());
            }

            width = w.get();
            height = h.get();
        }

        this.id = createTexture(imageBuffer);

        stbi_image_free(imageBuffer);
    }

    public Texture(ByteBuffer imageBuffer) throws Exception {
        ByteBuffer buf;
        // Load Texture file
        try (MemoryStack stack = MemoryStack.stackPush()) {
            IntBuffer w = stack.mallocInt(1);
            IntBuffer h = stack.mallocInt(1);
            IntBuffer channels = stack.mallocInt(1);

            buf = stbi_load_from_memory(imageBuffer, w, h, channels, 4);
            if (buf == null) {
                throw new IOException("Image file not loaded: " + stbi_failure_reason());
            }

            width = w.get();
            height = h.get();
        }

        this.id = createTexture(buf);

        stbi_image_free(buf);
    }

    private int createTexture(ByteBuffer buf) {
        // Create a new OpenGL texture
        int textureId = glGenTextures();
        // Bind the texture
        glBindTexture(GL_TEXTURE_2D, textureId);

        // Tell OpenGL how to unpack the RGBA bytes. Each component is 1 byte size
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

        // Upload the texture data
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
            GL_RGBA, GL_UNSIGNED_BYTE, buf);
        // Generate Mip Map
        glGenerateMipmap(GL_TEXTURE_2D);

        return textureId;
    }

    public int getWidth() {
        return this.width;
    }

    public int getHeight() {
        return this.height;
    }
    public void bind() {
        glBindTexture(GL_TEXTURE_2D, id);
    }

    public int getId() {
        return id;
    }

    public void cleanup() {
        glDeleteTextures(id);
    }
}