draw texture opengl code example
Example: how create Texture in OpenGL
val image = ImageIO.read(javaClass.getResourceAsStream("/$img"))
val pixels = IntArray(image.width * image.height)
image.getRGB(0, 0, image.width, image.height, pixels, 0, image.width)
val buffer: ByteBuffer = ByteBuffer.allocateDirect(image.width * image.height * 4)
for (h in 0 until image.height) {
for (w in 0 until image.width) {
val pixel = pixels[h * image.width + w]
buffer.put((pixel shr 16 and 0xFF).toByte())
buffer.put((pixel shr 8 and 0xFF).toByte())
buffer.put((pixel and 0xFF).toByte())
buffer.put((pixel shr 24 and 0xFF).toByte())
}
}
buffer.flip()
val id: Int = glGenTextures()
glBindTexture(GL_TEXTURE_2D, id)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, if(mipMap == MipMapType.PIXELATED) GL_NEAREST else GL11.GL_LINEAR)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, if(mipMap == MipMapType.PIXELATED) GL_NEAREST else GL11.GL_LINEAR)
glTexImage2D(
GL_TEXTURE_2D, 0, GL_RGBA8, image.width, image.height,
0, GL_RGBA, GL_UNSIGNED_BYTE, buffer
)
glGenerateMipmap(GL_TEXTURE_2D)
ID = id