io.github.mwttg.pixelartillery2d.graphic.Texture Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of pixel-artillery-2d Show documentation

A library for 2D OpenGL and OpenAL support based on LWJGL 3

The newest version!

package io.github.mwttg.pixelartillery2d.graphic;

import org.lwjgl.opengl.GL41;
import org.lwjgl.stb.STBImage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

final class Texture {

  private static final Logger LOG = LoggerFactory.getLogger(Texture.class);

  private Texture() {}

  /**
   * Creates a (OpenGL) Texture from an image file (like .png). Nearest filtering is used to have
   * 'pixel perfect' Textures (no interpolations).
   *
   * @param filename the path and filename to the image file for the texture
   * @return the OpenGL ID of the Texture
   */
  static int create(final String filename) {
    final var image = ImageFile.readFrom(filename);
    final var id = GL41.glGenTextures();
    GL41.glBindTexture(GL41.GL_TEXTURE_2D, id);
    GL41.glPixelStorei(GL41.GL_UNPACK_ALIGNMENT, 1);
    GL41.glTexImage2D(
        GL41.GL_TEXTURE_2D,
        0,
        GL41.GL_RGBA,
        image.width(),
        image.height(),
        0,
        GL41.GL_RGBA,
        GL41.GL_UNSIGNED_BYTE,
        image.pixels());
    // NEAREST Filtering instead of LINEAR for sharp edges, because we are using PixelArt
    GL41.glTexParameteri(
        GL41.GL_TEXTURE_2D, GL41.GL_TEXTURE_MIN_FILTER, GL41.GL_NEAREST_MIPMAP_NEAREST);
    GL41.glTexParameteri(GL41.GL_TEXTURE_2D, GL41.GL_TEXTURE_MAG_FILTER, GL41.GL_NEAREST);
    GL41.glGenerateMipmap(GL41.GL_TEXTURE_2D);
    STBImage.stbi_image_free(image.pixels());

    LOG.debug(
        "create Texture {}x{} with id='{}' from file '{}'",
        image.width(),
        image.height(),
        id,
        filename);
    OpenGlCleanUp.addTextureId(id);
    return id;
  }
}