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How do you update a texture in SDL?
Fortunately, the pitch SDL gives us is the number of bytes per row of pixels so all we have to do is multiply by the height of the surface to copy in all the pixels from the image. After we’re done copying the pixels from the surface to the texture, we unlock the texture to update it with the new pixels using SDL_UnlockTexture.
How do you grab pixels from a texture?
To grab the pixels from the texture we use SDL_LockTexture. The first argument is the texture we’ll be grabbing pixels from. The second argument is the region we want to grab pixels from and since we’re getting the pixels from the whole texture we set this argument to NULL.
How many pixels can a texture be padded to?
If you create a texture with a width of 100 pixels, it may get padded to 128 pixels wide (the next power of two). Using the pitch, we know how the image is in memory. In terms of data members we have a pointer to the pixels after we lock the texture and the pitch.
How to edit the pixel data of a texture?
If you plan to directly edit the pixel data of a texture, you must use SDL_TEXTUREACCESS_STREAMING instead. This flag tells SDL that the texture may be changed by external code. However, that’s not all you have to do. To access the pixel data of a texture, you must use the function SDL_LockTexture().
Can a texture be changed by external code?
This flag tells SDL that the texture may be changed by external code. However, that’s not all you have to do. To access the pixel data of a texture, you must use the function SDL_LockTexture(). This function tells SDL to stop any other access to the texture until the user is done with it.
Is there an SDL2 function that returns an array of pixels?
Is there an SDL2 function that returns an array of all the pixels of a texture or an SDL2 routine that I can use to loop over each pixel? SDL2’s “texture” rendering API is designed for accelerated graphics in mind; this is where you upload textures to your graphics hardware beforehand, and then render that texture by referring to it.