Hello Guest

OpenGL Array Texture Returns Only First or Last Texture

  • 0 Replies
  • 374 Views
OpenGL Array Texture Returns Only First or Last Texture
« on: April 04, 2018, 19:10:24 »
(I'm going to end up filling this forum up with all my struggles)

So, basically, I've got an array texture being set up like this:

Code: [Select]
texture = glGenTextures();
glBindTexture(GL_TEXTURE_2D_ARRAY, texture);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1); // 1 byte per component
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST); // Pixel perfect (with mipmapping)
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA, w, h, images.length, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
try {
for (int i = 0; i < images.length; i ++) {
InputStream is = Texture.class.getResourceAsStream(images[i].getFullPath());
if (is == null) {
throw new FileNotFoundException("Could not locate texture file: " + images[i].getFullPath());
}
PNGDecoder img = new PNGDecoder(is);
ByteBuffer buff = ByteBuffer.allocateDirect(4 * img.getWidth() * img.getHeight());
img.decode(buff, img.getWidth() * 4, Format.RGBA);
glPixelStorei(GL_UNPACK_ALIGNMENT, 4); // 1 byte per component
buff.flip();
glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, i, w, h, 1, GL_RGBA, GL_UNSIGNED_BYTE, buff);
Debug.log("{} => {}", i, images[i].getFullPath());
}

glGenerateMipmap(GL_TEXTURE_2D_ARRAY);

isCreated = true;
} catch (Exception e) {
Debug.error("Unable to create texture from path: {}", path);
Debug.error(e, true);
}

And to access it, I pass the texture id to the shader as an integer like this:

Code: [Select]
bindVertexArray();
glBindBuffer(GL_ARRAY_BUFFER, tbo);
glBufferData(GL_ARRAY_BUFFER, tBuff, GL_STATIC_DRAW);
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 1, GL_INT, false, 0, 0);
glDisableVertexAttribArray(2);
unbindVertexBuffer();
memFree(tBuff);
unbindVertexArray();

(tbo is the pointer to the buffer and tBuff is the integer buffer of ids)

Inside the shader, I simply do

Code: [Select]
fragColor = texture(samplerArr, vec3(uv, textureId));

However, only the last texture in the array is used unless the id is zero, in which case the first texture is used. I also tried sending through the total number of textures and diving those to return a vec3 with the z-value as a proportion rather than a specific id, but that only draw the first texture. With this information, can it be determined what I am doing wrong, or is there more to it?

(I'm sticking to GL 3.3, I don't want to go higher, mostly to stay compatible with most machines)
- A partial, semi-half game developer