My code:

public static ResourceLocation location = new ResourceLocation(MahouTsukaiMod.modId + ":textures/block/mahoujin_changeable.png")

IntBuffer colorBuf = BufferUtils.createIntBuffer(PIXEL_COUNT);

MahoujinData image = new MahoujinData(order);
this.bindTexture(location);

GlStateManager.glGetTexImage(GL11.GL_TEXTURE_2D, 0, GL12.GL_BGRA, GL12.GL_UNSIGNED_INT_8_8_8_8_REV, colorBuf);
colorBuf.get(image.colors);

 

 

This crashes at the last line with a BufferUnderflowException, only when Optifine is installed. I believe this means the "remaining" integers in colorBuf is less than the length of image.colors, even though I allocate colorBuf and image.colors with the width*height of the bound texture. So this tells me that glGetTexImage may be working differently and returning less pixels than the actual image's size in Optifine? I think the more likely case is that it's returning 0 pixels for some reason, since I'm using 

int side_size = GlStateManager.glGetTexLevelParameteri(GL11.GL_TEXTURE_2D, 0, GL11.GL_TEXTURE_WIDTH)

side_size = GlStateManager.glGetTexLevelParameteri(GL11.GL_TEXTURE_2D, 0, GL11.GL_TEXTURE_HEIGHT);

to grab the width and height dynamically. Any ideas why it would do this?

Nevermind, just learned this is a problem with Dynamic Texture in Optifine. DynamicTexture has an array 3x the size of what it should be when Optifine is installed... because Optifine is doing this 

new int[textureWidth * textureHeight * 3]

 

Edited September 30, 20196 yr by stepsword