author Sam Lantinga
Sun, 05 Apr 2020 08:58:47 -0700
changeset 13689 c3055b205671
parent 12674 e2d1f4e9c323
permissions -rw-r--r--
Fixed bug 5015 - SDL_RenderReadPixels on DirectX 11.1 backend seems to be broken


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 Mac OS X
     2 ==============================================================================
     4 These instructions are for people using Apple's Mac OS X (pronounced
     5 "ten").
     7 From the developer's point of view, OS X is a sort of hybrid Mac and
     8 Unix system, and you have the option of using either traditional
     9 command line tools or Apple's IDE Xcode.
    11 Command Line Build
    12 ==================
    14 To build SDL using the command line, use the standard configure and make
    15 process:
    17     ./configure
    18     make
    19     sudo make install
    21 You can also build SDL as a Universal library (a single binary for both
    22 32-bit and 64-bit Intel architectures), on Mac OS X 10.7 and newer, by using
    23 the script in build-scripts:
    25     mkdir mybuild
    26     cd mybuild
    27     CC=$PWD/../build-scripts/ CXX=$PWD/../build-scripts/ ../configure
    28     make
    29     sudo make install
    31 This script builds SDL with 10.5 ABI compatibility on i386 and 10.6
    32 ABI compatibility on x86_64 architectures.  For best compatibility you
    33 should compile your application the same way.
    35 Please note that building SDL requires at least Xcode 4.6 and the 10.7 SDK
    36 (even if you target back to 10.5 systems). PowerPC support for Mac OS X has
    37 been officially dropped as of SDL 2.0.2.
    39 To use the library once it's built, you essential have two possibilities:
    40 use the traditional autoconf/automake/make method, or use Xcode.
    42 ==============================================================================
    43 Caveats for using SDL with Mac OS X
    44 ==============================================================================
    46 Some things you have to be aware of when using SDL on Mac OS X:
    48 - If you register your own NSApplicationDelegate (using [NSApp setDelegate:]),
    49   SDL will not register its own. This means that SDL will not terminate using
    50   SDL_Quit if it receives a termination request, it will terminate like a 
    51   normal app, and it will not send a SDL_DROPFILE when you request to open a
    52   file with the app. To solve these issues, put the following code in your 
    53   NSApplicationDelegate implementation:
    56     - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
    57     {
    58         if (SDL_GetEventState(SDL_QUIT) == SDL_ENABLE) {
    59             SDL_Event event;
    60             event.type = SDL_QUIT;
    61             SDL_PushEvent(&event);
    62         }
    64         return NSTerminateCancel;
    65     }
    67     - (BOOL)application:(NSApplication *)theApplication openFile:(NSString *)filename
    68     {
    69         if (SDL_GetEventState(SDL_DROPFILE) == SDL_ENABLE) {
    70             SDL_Event event;
    71             event.type = SDL_DROPFILE;
    72             event.drop.file = SDL_strdup([filename UTF8String]);
    73             return (SDL_PushEvent(&event) > 0);
    74         }
    76         return NO;
    77     }
    79 ==============================================================================
    80 Using the Simple DirectMedia Layer with a traditional Makefile
    81 ==============================================================================
    83 An existing autoconf/automake build system for your SDL app has good chances
    84 to work almost unchanged on OS X. However, to produce a "real" Mac OS X binary
    85 that you can distribute to users, you need to put the generated binary into a
    86 so called "bundle", which basically is a fancy folder with a name like
    87 "".
    89 To get this build automatically, add something like the following rule to
    90 your
    92     bundle_contents =
    93     APP_NAME_bundle: EXE_NAME
    94     	mkdir -p $(bundle_contents)/MacOS
    95     	mkdir -p $(bundle_contents)/Resources
    96     	echo "APPL????" > $(bundle_contents)/PkgInfo
    97     	$(INSTALL_PROGRAM) $< $(bundle_contents)/MacOS/
    99 You should replace EXE_NAME with the name of the executable. APP_NAME is what
   100 will be visible to the user in the Finder. Usually it will be the same
   101 as EXE_NAME but capitalized. E.g. if EXE_NAME is "testgame" then APP_NAME 
   102 usually is "TestGame". You might also want to use `@PACKAGE@` to use the package
   103 name as specified in your file.
   105 If your project builds more than one application, you will have to do a bit
   106 more. For each of your target applications, you need a separate rule.
   108 If you want the created bundles to be installed, you may want to add this
   109 rule to your
   111     install-exec-hook: APP_NAME_bundle
   112     	rm -rf $(DESTDIR)$(prefix)/Applications/
   113     	mkdir -p $(DESTDIR)$(prefix)/Applications/
   114     	cp -r $< /$(DESTDIR)$(prefix)Applications/
   116 This rule takes the Bundle created by the rule from step 3 and installs them
   117 into "$(DESTDIR)$(prefix)/Applications/".
   119 Again, if you want to install multiple applications, you will have to augment
   120 the make rule accordingly.
   123 But beware! That is only part of the story! With the above, you end up with
   124 a bare bone .app bundle, which is double clickable from the Finder. But
   125 there are some more things you should do before shipping your product...
   127 1) The bundle right now probably is dynamically linked against SDL. That 
   128    means that when you copy it to another computer, *it will not run*,
   129    unless you also install SDL on that other computer. A good solution
   130    for this dilemma is to static link against SDL. On OS X, you can
   131    achieve that by linking against the libraries listed by
   133        sdl-config --static-libs
   135    instead of those listed by
   137        sdl-config --libs
   139    Depending on how exactly SDL is integrated into your build systems, the
   140    way to achieve that varies, so I won't describe it here in detail
   142 2) Add an 'Info.plist' to your application. That is a special XML file which
   143    contains some meta-information about your application (like some copyright
   144    information, the version of your app, the name of an optional icon file,
   145    and other things). Part of that information is displayed by the Finder
   146    when you click on the .app, or if you look at the "Get Info" window.
   147    More information about Info.plist files can be found on Apple's homepage.
   150 As a final remark, let me add that I use some of the techniques (and some
   151 variations of them) in Exult and ScummVM; both are available in source on
   152 the net, so feel free to take a peek at them for inspiration!
   155 ==============================================================================
   156 Using the Simple DirectMedia Layer with Xcode
   157 ==============================================================================
   159 These instructions are for using Apple's Xcode IDE to build SDL applications.
   161 - First steps
   163 The first thing to do is to unpack the Xcode.tar.gz archive in the
   164 top level SDL directory (where the Xcode.tar.gz archive resides).
   165 Because Stuffit Expander will unpack the archive into a subdirectory,
   166 you should unpack the archive manually from the command line:
   168     cd [path_to_SDL_source]
   169     tar zxf Xcode.tar.gz
   171 This will create a new folder called Xcode, which you can browse
   172 normally from the Finder.
   174 - Building the Framework
   176 The SDL Library is packaged as a framework bundle, an organized
   177 relocatable folder hierarchy of executable code, interface headers,
   178 and additional resources. For practical purposes, you can think of a 
   179 framework as a more user and system-friendly shared library, whose library
   180 file behaves more or less like a standard UNIX shared library.
   182 To build the framework, simply open the framework project and build it. 
   183 By default, the framework bundle "SDL.framework" is installed in 
   184 /Library/Frameworks. Therefore, the testers and project stationary expect
   185 it to be located there. However, it will function the same in any of the
   186 following locations:
   188     ~/Library/Frameworks
   189     /Local/Library/Frameworks
   190     /System/Library/Frameworks
   192 - Build Options
   193     There are two "Build Styles" (See the "Targets" tab) for SDL.
   194     "Deployment" should be used if you aren't tweaking the SDL library.
   195     "Development" should be used to debug SDL apps or the library itself.
   197 - Building the Testers
   198     Open the SDLTest project and build away!
   200 - Using the Project Stationary
   201     Copy the stationary to the indicated folders to access it from
   202     the "New Project" and "Add target" menus. What could be easier?
   204 - Setting up a new project by hand
   205     Some of you won't want to use the Stationary so I'll give some tips:
   206     * Create a new "Cocoa Application"
   207     * Add src/main/macosx/SDLMain.m , .h and .nib to your project
   208     * Remove "main.c" from your project
   209     * Remove "MainMenu.nib" from your project
   210     * Add "$(HOME)/Library/Frameworks/SDL.framework/Headers" to include path
   211     * Add "$(HOME)/Library/Frameworks" to the frameworks search path
   212     * Add "-framework SDL -framework Foundation -framework AppKit" to "OTHER_LDFLAGS"
   213     * Set the "Main Nib File" under "Application Settings" to "SDLMain.nib"
   214     * Add your files
   215     * Clean and build
   217 - Building from command line
   218     Use pbxbuild in the same directory as your .pbproj file
   220 - Running your app
   221     You can send command line args to your app by either invoking it from
   222     the command line (in *.app/Contents/MacOS) or by entering them in the
   223     "Executables" panel of the target settings.
   225 - Implementation Notes
   226     Some things that may be of interest about how it all works...
   227     * Working directory
   228         As defined in the SDL_main.m file, the working directory of your SDL app
   229         is by default set to its parent. You may wish to change this to better
   230         suit your needs.
   231     * You have a Cocoa App!
   232         Your SDL app is essentially a Cocoa application. When your app
   233         starts up and the libraries finish loading, a Cocoa procedure is called,
   234         which sets up the working directory and calls your main() method.
   235         You are free to modify your Cocoa app with generally no consequence 
   236         to SDL. You cannot, however, easily change the SDL window itself.
   237         Functionality may be added in the future to help this.
   240 Known bugs are listed in the file "BUGS.txt".