If it is given a texture different than the last texture, then it binds the last texture, submits the collected geometry to be drawn, and begins collecting geometry for the new texture.Ĭhanging textures every few rectangles that are drawn prevents SpriteBatch from batching much geometry. It collects the geometry without submitting it to the GPU. SpriteBatch is given a texture and coordinates for each rectangle to be drawn. Instead, many rectangles for the same texture can be described and sent to the GPU all at once. It would be inefficient to send each rectangle one at a time to the GPU to be drawn. It is also very common to draw the same texture or various regions of that texture many times. It is very common to draw a texture mapped to rectangular geometry. This means that the geometry is specified in pixels, which makes it easy to draw textures in the appropriate size and position on the screen. Many 2D games configure the viewport to match the screen resolution. The size and position on the screen that the texture is drawn is determined by both the geometry and how the OpenGL viewport is configured. To do the actual drawing, first the texture is bound (i.e., made the current texture), then the geometry is given to OpenGL to draw. A rectangle that is a subset of a texture is called a texture region. For example, the geometry could be a rectangle and the texture could be applied so that each corner of the rectangle corresponds to a corner of the texture.

To draw a texture, geometry is described and the texture is applied by specifying where each vertex in the geometry corresponds on the texture. Drawing imagesĪn image that has been decoded from its original format (e.g., PNG) and uploaded to the GPU is called a texture. This page gives a brief overview of how images are drawn using OpenGL and how libGDX simplifies and optimizes the task through the SpriteBatch class.

Gdx texturepacker not working