README-SDL.txt
author Sam Lantinga
Sun, 05 Apr 2020 08:58:47 -0700
changeset 13689 c3055b205671
parent 10892 996c14d41c46
permissions -rw-r--r--
Fixed bug 5015 - SDL_RenderReadPixels on DirectX 11.1 backend seems to be broken

Konrad

It appears that I cannot use SDL_RenderReadPixels on a bound framebuffer (SDL_Texture set as render target) as it simply results in gibberish data. However, drawing that framebuffer into the default target (window surface) does render it correctly. Other backends (OpenGL, software, Direct3D) do work fine.

It looks to me like D3D11_RenderReadPixels just gets the general backbuffer and not the current render target and its backbuffer.

Here is the patch which actually fetches the current render target and its underlying ID3D11Resource which is ID3D11Texture2D.
     1 
     2 Please distribute this file with the SDL runtime environment:
     3 
     4 The Simple DirectMedia Layer (SDL for short) is a cross-platform library
     5 designed to make it easy to write multi-media software, such as games
     6 and emulators.
     7 
     8 The Simple DirectMedia Layer library source code is available from:
     9 https://www.libsdl.org/
    10 
    11 This library is distributed under the terms of the zlib license:
    12 http://www.zlib.net/zlib_license.html
    13