Direct3D 9 dictates that caps.NumSimultaneousRTs must always be at least 1,
which is to say that Direct3D 9 level hardware must always support render
targets.
(caps.NumSimultaneousRTs is meant to show if you can draw to multiple render
targets in a single draw call.)
We had already hardcoded SDL_RENDERER_TARGETTEXTURE as available earlier in
the function anyhow.
Fixes#4781.
One place known to differ in a significant way is a single line segment that
starts and ends on the same point; the GL renderers will light up a single
pixel here, whereas the software renderer will not. My current belief is this
is a bug in the software renderer, based on the wording of the docs:
"SDL_RenderDrawLine() draws the line to include both end points."
You can see an example program that triggers that difference in Bug #2006.
As it stands, the GL renderers might _also_ render diagonal lines differently,
as the the Bresenham step might vary between implementations (one does three
pixels and then two, the other does two and then three, etc). But this patch
causes those lines to start and end on the correct pixel, and that's the best
we can do, and all anyone really needs here.
Not closing any bugs with this patch (yet!), but here are several that it
appears to fix. If no other corner cases pop up, we'll call this done.
Reference Bug #2006.
Reference Bug #1626.
Reference Bug #4001.
...and probably others...
In the future, we might want to support special swap intervals. To
prevent applications from expecting nonzero values of vsync to be the
same as "on", fail with SDL_Unsupported() if the value passed is neither
0 nor 1.
Currently, if an application wants to toggle VSync, they'd have to tear
down the renderer and recreate it. This patch fixes that by letting
applications call SDL_RenderSetVSync().
This is the same as the patch in #3673, except it applies to all
renderers (including PSP, even thought it seems that the VSync flag is
disabled for that renderer). Furthermore, the renderer flags also change
as well, which #3673 didn't do. It is also an API instead of using hint
callbacks (which could be potentially dangerous).
Closes#3673.
With Dear ImGui + software renderer, it draws:
- by default at 250 fps
- drops to 70 fps if you show the color picker
- drops to 10 fps if put the color picker fullscreen
This reintroduces the fix from 0e16ee8330, but just marks
the viewport state as dirty after a clear that needs to expand the
viewport to fill the render target, as we'll need to also reset
the orthographic projection state elsewhere, and that won't
happen if we clear the dirty flag here.
Fixes#4210.
(again.)
(...sorry...!)
The Renderer logical scaling code scales mouse coordinates, and needs to
take the window DPI into account on HIGHDPI windows. However, the
variable which tracks this, renderer->dpi_scale, is set once when the
renderer is created, and then not updated. In the event that the window
is moved to another screen, or the screen DPI otherwise changes, this
will be outdates, and potentially the coordinates will be all wrong.
So let's update the dpi_scale on the SIZE_CHANGED event: it's at least a
possibility that this will be issued on some OSes when DPI changes, and
it's otherwise already handled by SDL_Renderer's event filter.
Otherwise you might have set the viewport to the full size of
the render target in SDL's API but this change hasn't been
transmitted to Direct3D yet by the time we attempt to clear.
Fixes#4210.
The RenderDrawLinesWithRects and RenderDrawLinesWithRectsF functions can
sometimes call QueueCmdFillRects() with the data pointed to by frects
uninitialised. This can occur if none of the lines can be replaced with
rects, in which case the frects array is empty, and nrects is 0.
gcc 10.3.0 will detect this possibility, and print a warning like:
/home/david/Development/SDL/src/render/SDL_render.c: In function 'RenderDrawLinesWithRectsF':
/home/david/Development/SDL/src/render/SDL_render.c:2725:15: warning: '<unknown>' may be used uninitialized [-Wmaybe-uninitialized]
2725 | retval += QueueCmdFillRects(renderer, frects, nrects);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/david/Development/SDL/src/render/SDL_render.c:499:1: note: by argument 2 of type 'const SDL_FRect *' to 'QueueCmdFillRects' declared here
499 | QueueCmdFillRects(SDL_Renderer *renderer, const SDL_FRect * rects, const int count)
| ^~~~~~~~~~~~~~~~~
This is harmless, because when this is uninitialised, nrects is always
0, so QueueCmdFillRects() does nothing anyway. We therefore can work
around this by only calling QueueCmdFillRects() when nrects is nonzero.
Somewhat impressively, gcc recognises that this is now safe.
This is needed to support CHERI, and thus Arm's experimental Morello
prototype, where pointers are implemented using unforgeable capabilities
that include bounds and permissions metadata to provide fine-grained
spatial and referential memory safety, as well as revocation by sweeping
memory to provide heap temporal memory safety.
On most systems (anything with a flat memory hierarchy rather than using
segment-based addressing), size_t and uintptr_t are the same type.
However, on CHERI, size_t is just an integer offset, whereas uintptr_t
is still a capability as described above. Casting a pointer to size_t
will strip the metadata and validity tag, and casting from size_t to a
pointer will result in a null-derived capability whose validity tag is
not set, and thus cannot be dereferenced without faulting.
The audio and cursor casts were harmless as they intend to stuff an
integer into a pointer, but using uintptr_t is the idiomatic way to do
that and silences our compiler warnings (which our build tool makes
fatal by default as they often indicate real problems). The iconv and
egl casts were true positives as SDL_iconv_t and iconv_t are pointer
types, as is NativeDisplayType on most OSes, so this would have trapped
at run time when using the round-tripped pointers. The gles2 casts were
also harmless; the OpenGL API defines this argument to be a pointer type
(and uses the argument name "pointer"), but it in fact represents an
integer offset, so like audio and cursor the additional idiomatic cast
is needed to silence the warning.
Fixes SDL_CreateWindowAndRenderer (and similar situations) not choosing a Metal backend. See #3991.
Passing an explicit backend into CreateWindow, eg SDL_WINDOW_OPENGL or SDL_WINDOW_METAL, will still prevent the window from being used with other backend types.
This is caused by the Metal renderer recreating the window because by default we create an OpenGL window on macOS.
It turns out that at least on macOS 10.15, a window that has been initialized for OpenGL can also be used with Metal. So we'll skip recreating the window in that case.
UMU
#define SDL_COMPOSE_ERROR(str) SDL_STRINGIFY_ARG(__FUNCTION__) ", " str
I think SDL_STRINGIFY_ARG should be removed.
#define SDL_COMPOSE_ERROR(str) __FUNCTION__ ", " str
(verified with Visual Studio 2019)
C.W. Betts
I tested building commit http://hg.libsdl.org/SDL/rev/7adf3fdc19f3 on Mac Catalyst and found some issues:
* MTLFeatureSet_iOS_* enums aren't available under Mac Catalyst.
* OpenGL ES is unavailable under Mac Catalyst.
* Some Metal features are available under Catalyst but not iOS, such as displaySyncEnabled.
* Set Metal as the default renderer on Mac Catalyst
Attaching a patch that will make SDL2 build for Mac Catalyst.