src


Log

Author Commit Date CI Message
Sam Lantinga 710ae62a 2017-02-02T17:33:40 Remember XInput controllers that we've already seen, so when the raw device list changes we don't assign the old device to the new XInput userid. This isn't perfect, but at least we won't report the same device twice.
Sam Lantinga da30992d 2017-02-02T00:41:58 Fixed bug 3577 - Can't set minimal size (message box appears instead) if maximal size wasn't declared (i.e. unlimited)
Sam Lantinga be28d7c8 2017-01-31T12:30:55 Added support for the Saitek Pro Flight X-56 Rhino
Sam Lantinga 6717a3d3 2017-01-31T12:23:29 Added support for the HOTAS Warthog throttle
Sam Lantinga a156b0d9 2017-01-31T10:20:09 Added the HOTAS Warthog as a flight stick
Sam Lantinga 800a72eb 2017-01-31T10:19:56 Switch stderr output to SDL_Log() so it shows up on Windows and mobile devices
Sam Lantinga 52e9c42d 2017-01-28T14:35:35 Fixed Windows build
Sam Lantinga 869b7fe3 2017-01-28T11:17:10 Fixed bug 3550 - No mouse move messages send while over the titlebar and windows edges Matthew Its possible to set SDL_CaptureMouse() so you continue receiving mouse input while the mouse is outside your window. This works however There is then a gap where no messages send, which is when the mouse is hovering the title bar and the window edges.
R?mi Verschelde c3eea703 2017-01-28T10:54:12 Use a stronger X font definition for X11_MessageBox on UTF-8 X11 seemed to be confused by the broad definition, so WEIGHT_NAME, SLANT and SETWIDTH_NAME were defined, thus fixing the font lookup on some systems (tested on Mageia 6 with X11 1.19.1). Fixes bug 3571.
Sam Lantinga 13433c4a 2017-01-27T21:23:27 Fixed bug 3569 - GL_UpdateViewport leaves PROJECTION matrix selected Tom Seddon GL_ActivateRenderer may call GL_UpdateViewport, which leaves the GL_PROJECTION matrix selected. But after GL_ResetState, the GL_MODELVIEW matrix is selected, suggesting that's the intended default state. It seems at least like these should be consistent. Presumably GL_UpdateViewport should be doing a glMatrixMode(GL_MODELVIEW) before it finishes.
Sam Lantinga 0090a338 2017-01-27T21:16:38 Return an error if trying to set a window minimum size larger than the maximum size, or vice versa
Sam Lantinga d0247368 2017-01-27T18:06:50 Sorted controller entries
Ryan C. Gordon 8fa9b57f 2017-01-27T20:50:30 windows: first shot at naming threads with SetThreadDescription(). This is a bleeding edge API, added to Windows 10 Anniversary Edition (build 1607, specifically). https://msdn.microsoft.com/en-us/library/windows/desktop/mt774976(v=vs.85).aspx Nothing supports this yet, including WinDbg, Visual Studio, minidumps, etc, so we still need to also use the RaiseException hack. But presumably tools will use this API as a more robust and universal way to get thread names sooner or later, so we'll start broadcasting to it now.
Sam Lantinga 95ab9dc7 2017-01-27T06:05:50 Added Thrustmaster Wheel FFB entry to the list of wheels
Sam Lantinga 3c90a52a 2017-01-27T05:59:58 Added an API to get the type of a connected joystick
Jessica Stokes aa90b730 2017-01-26T21:25:05 Add a mapping for Xbox Wireless Controllers running old firmware Also updates the naming of these Xbox Wireless Controllers connected via USB (and thus the third-party Xbox Controller Driver) to match. The Xbox Wireless Controller entries are now listed, in order, via USB, bia Bluetooh (with older firmware) and via Bluetooth (with firmware 3.1.1221.0).
Misty De Meo ae5e9a31 2017-01-25T22:24:54 Add gamecontrollerdb mapping for Xbox One S on Mac This is valid for firmware version 3.1.1221.0; earlier versions of the firmware need a different mapping (and have different GUIDs).
Misty De Meo ca89d9b5 2017-01-25T22:22:05 Darwin: fix detection of Xbox One S controller Firmware revision 3.1.1221.0 changes the mapping of the Xbox One S controller in Bluetooth mode. Aside from changing the layout of other buttons, this revision also changes the triggers to act as Accelerator and Brake axes from the simulation controls page. The Darwin sysjoystick code didn't previously map anything at these axes, making it impossible to detect input on these two buttons.
Sam Lantinga ede5c734 2017-01-24T19:38:01 Generalized the audio resampling hint for other resampling methods in the future
Ryan C. Gordon 47e2f4e9 2017-01-24T20:30:48 audio: libsamplerate can't resample in-place; make space for a copy if needed.
Ryan C. Gordon c7f9dcb6 2017-01-24T15:52:22 audio: Offer a hint for libsamplerate quality/speed tradeoff. This defaults to the internal SDL resampler, since that's the likely default without a system-wide install of libsamplerate, but those that need more can tweak this.
Ryan C. Gordon 1da3a337 2017-01-24T10:09:29 audio: Fix static analysis concerns about a dead assignment.
Ryan C. Gordon 8f627c1c 2017-01-24T00:51:33 audio: Make sure SDL_AudioStream's work buffer is 16-byte aligned, for SIMD. Note the giantic FIXME, though!
Ryan C. Gordon 17dcee20 2017-01-24T00:17:40 audio: Streams now resample in-place. Removed second allocated buffer.
Ryan C. Gordon b5eeab77 2017-01-24T00:08:24 audio: allow stereo Sint16 resampling fast path in SDL_AudioStream. This currently favors libsamplerate over the fast path (quality over speed), but I'm not sure that's the correct approach, as there may be surprising changes in performance metrics depending on what packages are available on a user's system. That being said, currently, the only thing with access to SDL_AudioStream is an SDL audio device's thread, and it might be mostly idle otherwise, so maybe this is generally good.
Ryan C. Gordon a80cb672 2017-01-24T00:03:36 audio: Fixed off-by-one error in upsampling.
Ryan C. Gordon dad07f96 2017-01-23T16:45:50 audio: Resampler now special-cases stereo and mono processing. Turns out that iterating from 0 to channels-1 was a serious performance hit! These cases now tend to match or beat the original audio resampler's speed!
Ryan C. Gordon 8ce6ddf1 2017-01-23T16:42:47 audio: Fixed incorrect pointer in SDL_ResampleCVT_si16_c2(). Forgot to update this when we changed this to process in-place. Whoops!
Ryan C. Gordon ecdc6c12 2017-01-23T12:14:28 audio: Fixed copy/paste bug in float32->sint16/SSE2 scalar leftover code.
Ryan C. Gordon 4b8f3546 2017-01-23T12:06:10 audio: Fix same bug as last commit, but for _mm_bslli_si128 vs _mm_slli_si128.
Ryan C. Gordon fab45018 2017-01-23T12:02:02 audio: use _mm_srli_si128 instead of _mm_bsrli_si128. They're the same thing (one is generally a #define of the other), but some toolchains don't offer the 'b' version.
Ryan C. Gordon 3594bf8e 2017-01-23T01:05:44 audio: Wired up new SSE code to build system.
Ryan C. Gordon 64056e81 2017-01-23T00:57:19 audio: Added SSE3 implementation of SDL_ConvertStereoToMono().
Ryan C. Gordon 8855daac 2017-01-22T23:48:15 audio: Make the simple resampler operate in-place. This allows us to avoid an extra copy, allocate less memory and reduce cache pressure. On the downside: we have to do a lot of tapdancing to resample the buffer in reverse when the output is growing.
Ryan C. Gordon 202ab30c 2017-01-22T20:27:48 audio: Special case for resampling stereo AUDIO_S16SYS audio data. This is a fairly common case, so we avoid the conversion to/from float here.
Ryan C. Gordon a7f86f2f 2017-01-22T20:18:59 audio: don't cast to double in SDL_ConvertStereoToMono(). It's expensive and (hopefully) unnecessary. If this becomes an overflow problem, we could multiply both values by 0.5f before adding them, but let's see if we can get by without the extra multiplication first.
Philipp Wiesemann 4f981df3 2017-01-22T22:15:36 Haiku: Fixed memory leak if creating framebuffer failed.
Philipp Wiesemann 63e83a31 2017-01-21T22:01:17 Haiku: Removed unused variable. Found by Cppcheck.
Philipp Wiesemann 800a9e84 2017-01-21T22:00:56 Fixed compiler warning about returning a value in a void function.
Ryan C. Gordon 83454c82 2017-01-20T16:26:24 audio: removed conditional from simple resampler's inner loop. We never seem to overflow the source buffer now; this might have been a leftover from a bug that was covered by Vitaly's fixes? Removing this conditional makes the resampler 10-20% faster. Left an assert in there for debug builds, in case this still happens.
Sam Lantinga 8fa0b088 2017-01-20T08:13:23 Added support for the 8Bitdo Zero GamePad
Sam Lantinga 9b99265a 2017-01-19T20:19:37 Fixed mingw64 32-bit build, which does have the correct structure definitions
Sam Lantinga f3540242 2017-01-18T12:19:57 Removed unused variable
Sam Lantinga b0c5ceef 2017-01-18T12:18:50 Fixed bug 3533 - Enumeration joystick devices omitted during directinput enumeration white.magic The logic which decides if a device enumerated via the direct input system in the function EnumJoysticksCallback in SDL_dinputjoystick.c is processed is discarding valid joystick devices due to the assumption that devices of the type DI8DEVTYPE_SUPPLEMENTAL are not valid devices. This change was added with 2.0.4 with this commit http://hg.libsdl.org/SDL/rev/1b9d40126645 that is linked to this bug report https://bugzilla.libsdl.org/show_bug.cgi?id=2460 which indicates that in that case devices of the type DI8DEVTYPE_SUPPLEMENTAL were not desirable as they caused a singular device to emit multiple "device added" events. Since then there appear to have been a few fixes to handle devices that fall into various other classes in the following two commits: http://hg.libsdl.org/SDL/rev/10ffb4787d7a and http://hg.libsdl.org/SDL/rev/6a2bbac05728 Two devices I have reports of failing to be listed when the DI8DEVTYPE_SUPPLEMENTAL type is excluded are ECS Gametric Throttle and Thrustmaster MFD Cougar. Sam Lantinga I verified that the OUYA controller shows up as a single device with this change, so I've reverted the change to ignore supplemental devices, leaving framework in place to easily add devices that we want to ignore.
Sam Lantinga dd007e3f 2017-01-18T11:58:16 Fixed bug 3561 - Re-acquire device before playing effects if needed. Mathieu Laurendeau Check the result of IDirectInputEffect_SetParameters and re-acquire the device to solve concurrency issues.
Sam Lantinga 5cb1ca55 2017-01-18T11:57:27 Fixed building with mingw32
Ryan C. Gordon 3e1679c8 2017-01-18T02:11:56 audio: Several fixes to "simple" resampler (thanks, Vitaly!). Fixes Bugzilla #3551.
Sam Lantinga 95defd66 2017-01-17T21:18:31 Use icon width * sizeof(Uint32) instead of icon pitch when copying to icon resource data
Ryan C. Gordon 57182930 2017-01-16T00:58:28 audio: Implemented SIMD support for audio data type converters. This currently adds an SSE2 implementation (but it's #ifdef'd out for now, until it's hooked up to the configure script and such).
Ryan C. Gordon 1e66d457 2017-01-15T05:01:59 audio: Some fixes to the audio data type converter code. Removed some needless things ("len / sizeof (Uint8)"), and made sure the int32 -> float code uses doubles to avoid working with large integer values in a 32-bit float.
Philipp Wiesemann 1e482095 2017-01-14T21:36:06 Fixed comments.
Sam Lantinga 341d1ff9 2017-01-13T11:37:12 Fixed comment
Sam Lantinga a52d48c5 2017-01-10T08:54:33 Fixed bugs 2570, 3145, improved OpenGL ES context support on Windows and X11 Mark Callow The attached patch does the following for the X11 and Windows platforms, the only ones where SDL attempts to use context_create_es_profile: - Adds SDL_HINT_OPENGL_ES_DRIVER by which the application can say to use the OpenGL ES driver & EGL rather than the Open GL driver. (For bug #2570) - Adds code to {WIN,X11}_GL_InitExtensions to determine the maximum OpenGL ES version supported by the OpenGL driver (for bug #3145) - Modifies the test that determines whether to use the OpenGL driver or the real OpenGL ES driver to take into account the hint, the requested and supported ES version and whether ES 1.X is being requested. (For bug #2570 & bug #3145) - Enables the testgles2 test for __WINDOWS__ and __LINUX__ and adds the test to the VisualC projects. With the fix in place I have run testdraw2, testgl and testgles2 without any issues and have run my own apps that use OpenGL, OpenGL ES 3 and OpenGL ES 1.1.
Sam Lantinga bf11cd50 2017-01-09T20:37:52 Fixed bug 3552 - Building SDL in release mode fails under VS 2017 RC Lukasz Biel Tried to compile SDL2 using newest version of VS. Got: SDL_audiocvt.obj : error LNK2019: unresolved external symbol memcpy referenced in function SDL_ResampleCVT 1>E:\Users\dotPo\Lib\SDL\VisualC\x64\Release\SDL2.dll : fatal error LNK1120: 1 unresolved externals whole compilation process: http://pastebin.com/eWDAvBce Steps to reproduce: clone http://hg.libsdl.org/SDL using tortoise hg, open SDL\VisualC\SDL.sln, when promted if should retarget solution click ok, select release x64 build type, Build/Build Solution attempt 2, using Visual Studio cmake support: open folder SDL\ select release x64 build type, run CMake\Build CMakeLists.txt build fails When switched to debug build type, buils succeeds in both cases. VS 2017 is still beta.
Ryan C. Gordon 23020f92 2017-01-09T16:31:57 audio: Don't ever use libsamplerate in the SDL_AudioCVT codepath. It causes audio pops if you're converting in chunks (and needs to allocate/initialize/free on each convert). We'll either adjust this interface when we break ABI for 2.1 to make this usable, or publish the SDL_AudioStream API for those that want a streaming solution. In the meantime, the "simple" resampler produces "good enough" audio without pops and doesn't have to be initialized, so that'll do for now on the SDL_AudioCVT interface.
Sam Lantinga ad7c26ff 2017-01-09T11:58:01 We only need the first few keymaps corresponding to the following constants: K_NORMTAB, K_SHIFTTAB, K_ALTTAB, K_ALTSHIFTTAB In the normal case we'll load all the keymaps from the kernel, but this reduces the size of the SDL library for the fallback case when we can't get to the tty.
Sam Lantinga 6d6edcb8 2017-01-09T11:30:29 Fixed spacing
Sam Lantinga 4e9c9fce 2017-01-09T10:10:33 Fixed bug 3100 - SetSwapInterval should now be enabled for ANGLE/EGL Mark Logan 2015-08-24 15:57:50 UTC In SDL_windowsopengles.c, WIN_GLES_SetSwapInterval is as follows: WIN_GLES_SetSwapInterval(_THIS, int interval) { /* FIXME: This should call SDL_EGL_SetSwapInterval, but ANGLE has a bug that prevents this * from working if we do (the window contents freeze and don't swap properly). So, we ignore * the request for now. */ SDL_Log("WARNING: Ignoring SDL_GL_SetSwapInterval call due to ANGLE bug"); return 0; } With a recent version of ANGLE (early July) calling SDL_EGL_SetSwapInterval with a D3D11 backend appears to work just fine. I am working on testing this with D3D9. -- Alex Szpakowski I found the bug, it was fixed in 2013. https://bugs.chromium.org/p/angleproject/issues/detail?id=481 In my opinion it should be safe to unconditionally use SetSwapInterval now. Anyone who encounters the bug should update their ANGLE to a version less than 3 years old, especially since they'd be using a SDL version that's 3+ years newer than their ANGLE version.
Ryan C. Gordon 063c9d40 2017-01-09T06:00:58 audio: Replaced older resamplers in SDL_AudioCVT with the new ones.
Ryan C. Gordon a41103b1 2017-01-09T05:59:30 audio: Patched to compile if linking directly to libsamplerate.
Sam Lantinga e0a40fb6 2017-01-09T02:54:42 Implemented full evdev keyboard text support This is based on the Linux kernel driver, and has fallback mapping tables in case we aren't connected to a virtual terminal.
Sam Lantinga 49292705 2017-01-08T20:03:18 Fixed bug 3545 - SDL_EVDEV_do_text_input() may be too eager to find error cases Rob I've ran into an issue where I successfully receive SDL_KEY[UP,DOWN] events but not SDL_TEXTINPUT or SDL_TEXTEDITING. In my case the code in SDL_EVDEV_do_text_input() is returning early (on error) prior to calling SDL_SendKeyboardText(). I'm running on the RaspberryPi 3, without X11. In SDL_EVDEV_do_text_input() there is a condition to check keysyms with a type value below 0xf0, then subtract 0xf0 from type. Without understanding the purpose of this code, I disabled it, recompiled, and I'm getting correct SDL_TEXTINPUT events. I'm going to guess that my hack/fix is going to be problematic in some other environment, but after some initial testing it looks like everything is running fine in my setup.
Sam Lantinga 7b66295e 2017-01-08T19:04:38 Removed console check, let the kernel decide whether muting is appropriate on this terminal. We don't fail the init if we can't mute the terminal (we might be running from ssh, or on a system without virtual terminals, etc.)
Sam Lantinga c16dd74f 2017-01-08T18:32:20 Check the return value of SDL_EVDEV_Init()
Ryan C. Gordon 38854e03 2017-01-08T16:18:49 audio: Improvements in channel conversion code.
Ryan C. Gordon 35166609 2017-01-08T14:28:44 audio: Patched to compile with libsamplerate support (again).
Ryan C. Gordon d005dc21 2017-01-08T14:23:15 audio: Patched to compile with libsamplerate support.
Ryan C. Gordon 19e937fc 2017-01-08T14:18:03 audio: libsamplerate loading now happens once at init time.
Ryan C. Gordon 98cc9d10 2017-01-08T14:17:09 Fixed coding style on a function signature.
Sam Lantinga 9d9e92cf 2017-01-08T10:41:22 Fixed bug 3304 - Android black screen on resume Richard Russell Resuming from a suspended state results in a black screen. This only happens when using GLES 1.1 (GLES 2 resumes correctly) and when the render target has been changed using SDL_SetRenderTarget. This problem is new in 2.0.4. The attached test case demonstrates the issue. Sylvain Becker has apparently found a fix as follows: "In the opengles leaf function (in 'src/render/opengles/SDL_render_gles.c'), it appears there is a call to 'GLES_ActivateRenderer' in 'GLES_SetRenderTarget', which is not present in opengles2. When commenting out this 'GLES_ActivateRenderer', it seems to resume fine". This appears to fix the testcase perfectly, but I don't know whether it could have any undesirable side-effects.
Sam Lantinga b8ab4eb9 2017-01-08T10:15:22 SDL_evdev.c: fix building against old kernel headers (K_OFF may not be defined.)
Ryan C. Gordon 13f2e542 2017-01-07T19:55:29 x11: make the X11 target work on macOS with Xquartz.
Sam Lantinga e25f4e50 2017-01-07T16:51:48 Really fixed blit issue for capehill
Sam Lantinga 7e505b0d 2017-01-07T16:49:23 Don't fail if we can't open the tty, this can be a legitimate use case.
Ryan C. Gordon 61a3ba30 2017-01-07T17:09:14 Replaced a few single-line "//" comments.
Sam Lantinga 267c9509 2017-01-07T13:47:34 Added mappings for the 8Bitdo NES30 Pro and iBuffalo SNES Controller Also swapped the Wii U Pro controller button mappings to position instead of label, as emulators expect from XBox controllers.
Sam Lantinga e9c2dcda 2017-01-07T10:13:04 Fixed bug 3469 - Keypresses leak to the console with 2.0.5 tvc I believe this patch should fix it, instead of looping through all the tty's and seemingly selecting the wrong one and corrupting the console I've just made SDL open /dev/tty which is the console attached to the current process anyway.
Sam Lantinga df25258a 2017-01-06T20:43:53 Added configure and cmake support for libsamplerate
Ryan C. Gordon c5825b69 2017-01-06T21:23:51 audio: Don't call a NULL function pointer when clearing audio streams. (Partially?) fixes Bugzilla #3547.
Ryan C. Gordon c1ac4c68 2017-01-06T21:17:33 Better fix for static analysis issue in SDL_DestroyRenderer(). Follow up fix for Bugzilla #3544.
Sam Lantinga cbe44f7f 2017-01-06T02:16:26 Added support for using libsamplerate to do audio resampling
Sam Lantinga 37f404fb 2017-01-06T00:47:42 Fixed confusion between Ryan's new audio stream and the audio buffer we were calling stream in the callback
Sam Lantinga 3df77ced 2017-01-06T00:40:22 Just roll back the entire portion of the commit from a8253d439914 which caused bug 3544 until we figure out what the right static analysis fix is.
Ryan C. Gordon 748f4605 2017-01-06T03:38:14 audio: Add an assert to make sure non-streaming audio uses good buffer sizes.
Sam Lantinga 356c2ead 2017-01-06T00:32:06 Fixed bug 3544 - Memory freeing bug in SDL_DestroyRenderer/SDL_DestroyTexture felix Here's a snippet of SDL_DestroyRenderer from hg revision 10746:7540ff5d0e0e: SDL_Texture *texture = NULL; SDL_Texture *nexttexture = NULL; /* ... */ for (texture = renderer->textures; texture; texture = nexttexture) { nexttexture = texture->next; SDL_DestroyTexture(texture); } SDL_DestroyTexture removes the texture from the linked list pointed to by the renderer and ends up calling SDL_DestroyTextureInternal, which contains this: if (texture->native) { SDL_DestroyTexture(texture->native); } If it happens that texture->native is an alias of nexttexture two stack frames up, SDL_DestroyRenderer will end up trying to destroy an already freed texture. I've had this very situation happen in dosemu2. Bug introduced in revision 10650:a8253d439914, which has a somewhat ironic description of "Fixed all known static analysis bugs"...
Ryan C. Gordon 345c5989 2017-01-06T03:15:27 haiku: Patched to compile.
Sam Lantinga 3443dc19 2017-01-05T23:53:46 Don't do any audio conversion if none is necessary
Sam Lantinga 41be9756 2017-01-05T23:26:13 Fixed bug 3546 - SDL_EVDEV_is_console() uses type of wrong size when calling ioctl Rob When calling ioctl(fd, KDGKBTYPE, &type) in SDL_EVDEV_is_console(), we declare type as an 'int'. This should be a 'char'. The subsequent syscall, and kernel code, only writes the lower byte of the word. See: http://lxr.free-electrons.com/source/drivers/tty/vt/vt_ioctl.c?v=4.4#L399 ucval = KB_101; ret = put_user(ucval, (char __user *)arg); I've observed intermittent behavior related to this, and I can force an error condition by using an int initialized to 0xFFFFFFFF. The resulting ioctl will set type to 0XFFFFFF02, and the conditional return in SDL_EVDEV_is_console() will fail. Recommend changing to char, or masking off unused bits.
Ryan C. Gordon b3e8db80 2017-01-06T01:07:34 audio: rename fake_stream to work_buffer. It's more than an alternative for when the OS can't provide a DMA buffer, now.
Ryan C. Gordon 992124d4 2017-01-06T01:02:58 audio: Fixed SDL_AudioStreamGet() function parameters. There was a draft of this where it did audio conversion into the final buffer, if there was enough room available past what you asked for, but that interface got removed, so the parameters didn't make sense (and we were using the wrong one in any case, too!).
Ryan C. Gordon 99fc1ef9 2017-01-06T00:56:29 naclaudio: Untested attempt to migrate to SDL_AudioStream.
Ryan C. Gordon 115d0ce7 2017-01-06T00:50:01 haikuaudio: Untested attempt to get this working with SDL_AudioStream.
Ryan C. Gordon 1a90c72d 2017-01-06T00:49:35 emscriptenaudio: don't get stuck in infinite loop if SDL_AudioStreamPut fails.
Ryan C. Gordon f07a1a5a 2017-01-05T21:31:02 emscriptenaudio: Reworked to use SDL_AudioStream.
Ryan C. Gordon 3761b5f6 2017-01-05T20:11:19 Fixed a few compiler warnings.
Ryan C. Gordon 4aa9e369 2017-01-05T19:45:57 Patched to compile on some compilers.
Ryan C. Gordon 52130bde 2017-01-05T19:30:45 diskaudio: Use SDL_Log, not fprintf.
Ryan C. Gordon 30178a9b 2017-01-05T19:29:38 audio: Added SDL_AudioStream. Non-power-of-two resampling now works!
Ryan C. Gordon f12ab8f2 2017-01-05T19:12:20 audio: More effort to improve and simplify audio resamplers.
Sam Lantinga d024c724 2017-01-05T08:16:39 Fixed signedness issue when blitting on a big endian platform, as reported by capehill For example, if sR is 0 and dR is 255, we will get -255*sA casted to an unsigned value. Basically results are quite large numbers instead of the expected 0-255 range.