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.
Otherwise our cached state goes out of sync when updating a texture. Since
these state changes aren't necessary, they were removed instead of updating
the cached state.
Fixes Bugzilla #4998.
cmediaplayer
Hi, i already mentioned in the SDL discourse a bug that recreating of a texture occours pixel shader problem on direct3d renderer. There is no problem for direct3d11. You can see the issue by using my app named C Media Player which is available for Windows for free using my web site www.cmediaplayer.com. Just follow the steps:
*Open a media file
*When playing the file change the scale quality under the video menu.
*You will see the problem.
This is the OpenGL line drawing fix for Bugzilla #3182, but there's some
disagreement about what the renderers should do here, so I'm backing this out
until after 2.0.12 ships, and then we'll reevaluate all the renderer backends
to decide what's correct, and make them all work the same.
Likewise for the GLES1 and GLES2 renderers.
This solves the missing pixel at the end of a line and removes all the
heuristics for various platforms/drivers. It's possible we could still use
GL_LINE_STRIP with this and save some vertex buffer space, assuming this
doesn't upset some driver somewhere, but this seems to be a clean fix that
makes the GL renderers match the software renderer output.
Diamond-exit rule explanation:
http://graphics-software-engineer.blogspot.com/2012/04/rasterization-rules.html
Fixes Bugzilla #3182.
Konrad
This kind of blending is rather quite useful and in my opinion should be available for all renderers. I do need it myself, but since I didn't want to use a custom blending mode which is supported only by certain renderers (e.g. not in software which is quite important for me) I did write implementation of SDL_BLENDMODE_MUL for all renderers altogether.
SDL_BLENDMODE_MUL implements following equation:
dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA))
dstA = (srcA * dstA) + (dstA * (1-srcA))
Background:
https://i.imgur.com/UsYhydP.png
Blended texture:
https://i.imgur.com/0juXQcV.png
Result for SDL_BLENDMODE_MOD:
https://i.imgur.com/wgNSgUl.png
Result for SDL_BLENDMODE_MUL:
https://i.imgur.com/Veokzim.png
I think I did cover all possibilities within included patch, but I didn't write any tests for SDL_BLENDMODE_MUL, so it would be lovely if someone could do it.
Konrad
This was something rather trivial to add, but asked at least several times before (I did google about it as well).
It should be possible to dynamically change scaling mode of the texture. It is actually trivial task, but until now it was only possible with a hint before creating a texture.
I needed it for my game as well, so I took the liberty of writing it myself.
This patch adds following functions:
SDL_SetTextureScaleMode(SDL_Texture * texture, SDL_ScaleMode scaleMode);
SDL_GetTextureScaleMode(SDL_Texture * texture, SDL_ScaleMode *scaleMode);
That way you can change texture scaling on the fly.
warning: either cast from 'int' to 'size_t' (aka 'unsigned long') is ineffective, or there is loss of precision before the conversion [bugprone-misplaced-widening-cast]
Sylvain
I think what happening with the software renderer is:
* you're somehow in background (so texture creation is not possible)
* it resizes and wants to push a SDL_WINDOWEVENT_SIZE_CHANGED
It call:
https://hg.libsdl.org/SDL/file/a010811d40dd/src/render/SDL_render.c#l683
* GetOutputSize
* SW_GetOutputSize
* SW_ActivateRenderer
* SDL_GetWindowSurface
* SDL_CreateWindowFramebuffer which is mapped to SDL_CreateWindowTexture
and it ends up re-creating the surface/a texture, while being in background
Sylvain
Currently SDL_CreateTextureFromSurface picks first valid format, and do a conversion.
format = renderer->info.texture_formats[0];
for (i = 0; i < renderer->info.num_texture_formats; ++i) {
if (!SDL_ISPIXELFORMAT_FOURCC(renderer->info.texture_formats[i]) &&
SDL_ISPIXELFORMAT_ALPHA(renderer->info.texture_formats[i]) == needAlpha) {
format = renderer->info.texture_formats[i];
break;
It could try to find a better format, for instance :
if SDL_Surface has no Amask, but a colorkey :
if surface fmt is RGB888, try to pick ARGB8888 renderer fmt
if surface fmt is BGR888, try to pick ABGR8888 renderer fmt
else
try to pick the same renderer format as surface fmt
if no format has been picked, use the fallback.
I think it goes with bug 4290 fastpath BlitNtoN
when you expand a surface with pixel format of size 24 to 32, there is a fast path possible.
So with this issue:
- if you have a surface with colorkey (RGB or BGR, not palette), it takes a renderer format where the conversion is faster.
(it avoids, if possible, RGB -> ABGR which means switching RGB to BGR)
- if you have a surface ABGR format, it try to take the ABGR from the renderer.
(it avoids, if possible, ABGR -> ARGB, which means switch RGB to BGR)
Sylvain
OpenGLES2 SDL renderer has support for textures ARGB, ABGR, RGB and BGR, whereas OpenGL SDL renderer only had ARGB.
If you think it's worth adding it, here's a patch. I quickly tried and it worked, but there may be missing things or corner case.
This is the best option for macOS and iOS, the only platforms with Metal.
Pre-Metal versions of these platforms will fall back to OpenGL (ES), as
appropriate.
Huge thanks to Alexander Szpakowski, who worked incredibly hard to get the
Metal renderer to such a high-quality state!
./src/render/SDL_render.c(2168): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2168): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2175): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2175): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2322): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/SDL_render.c(2329): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
./src/render/software/SDL_render_sw.c(602): Error! E1054: Expression must be constant
https://bugzilla.libsdl.org/show_bug.cgi?id=4350
We can't safely call GL_DestroyRenderer() until GL_LoadFunctions()
succeeds because we will be missing functions that we try to use
when activating the renderer for destruction if we have an GL context.
Sylvain
Re-opening this issue.
It fixes the test-case, but it introduces a regression with another bug (bug #4313).
So here's a new patch that activate cropping of the source surface to solve the issue.
It also reverts the wrong changeset.
It prevents unneeded colorkey error message.
Include guards in most changed files were missing, I added them keeping
the same style as other SDL files. In some cases I moved the include
guards around to be the first thing the header has to take advantage of
any possible improvements compiler may have for inclusion guards.
I have no idea if this works (or if it ever worked, having now examined this
code), as I have no way to compile or test this.
If it's broken, send patches. :)
This means it doesn't have to block while the current frame finishes using the
vertex buffer; it just moves on to the next, probably-not-in-use buffer.
- high-level filters out duplicate render commands from the queue so
backends don't have to.
- Setting draw color is now a render command, so backends can put color
information into the vertex buffer to upload with everything else instead
of setting it with slower dynamic data later.
- backends can request that they always batch, even for legacy programs,
since the lowlevel API can deal with it (Metal, and eventually Vulkan
and such...)
- high-level makes sure the queue has at least one setdrawcolor and
setviewport command before any draw calls, so the backends don't ever have
to manage cases where this hasn't been explicitly set yet.
- backends allocating vertex buffer space can specify alignment, and the
high-level will keep track of gaps in the buffer between the last used
positions and the aligned data that can be used for later allocations
(Metal and such need to specify some constant data on 256 byte boundaries,
but we don't want to waste all that space we had to skip to meet alignment
requirements).
It now uses a growable linked list that keeps a pool of allocated items for
reuse, and reallocs the vertex array as necessary. Testsprite2 can scale to
20,000 (or more!) draws now without drama.
This moves all the rendering to a command list that is flushed to the GL as
necessary, making most common activities upload a single vertex buffer per
frame and dramatically reducing state changes. In pathological cases,
like Emscripten running on iOS's Safari, performance can go from a dozen
draw calls killing your performance to 1000 draw calls running smoothly.
This is work in progress, and not ready to ship. Among other things, it has
a hardcoded array that isn't checked for overflow. But the basic idea is
sound!
Sam Lantinga
Ryan C. Gordon
Sylvain Becker
Cameron Gutman
Ozkan Sezer
Alex Szpakowski
Cameron Gutman
Micha? Janiszewski
