We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

Created attachment 2714 [details]
clip test v2

After adding a test file to bug #2700, this bug popped up.
Completing the test file a little more, showed a few more rare use case problems.
I could split this up into multiple reports if needed,
copy-pasted from test file:
(note that proposed fixes have not been tested)
-----------------------

observed problems: (some of these have been reported)

-software render + viewport + clip_rectangle
	, test 3,4,7 and 8 show this.
+ bug ID #3612 (SDL_render_sw.c, line 368, SW_UpdateClipRect(): viewport offset is missing)

-software render + viewport + SDL_RenderReadPixels
	, the read offset is incorrect when a viewport is used
	, can test this with taking a screen shot from test 3,4,7 and 8.
+ (SDL_render_sw.c, line 842: viewport offset is added a second time)

-Windows 7 opengl + SDL_RenderReadPixels
	does NOT correspond to what is shown
	, looks like its always a frame behind
	, screen shots taken will be an image from the previous test... press 'r' to force a repaint
+ ?Related? bug ID #3619 (different OS, debian did gave correct results for me)

-SDL_SetRenderTarget(ren, target) + logical size
	a logical size is set by default
	, test 4 and 6 shows this, a logical-size is detected and used as a backup (line 212 in here)
	, only the first time it is drawn correctly, press 'r' to refresh
+ (SDL_render.c, line 1124: renderer->logical_w/h should be initialized to 0, not the texture->w/h)

-opengl(es2) render + scale
	default render and target texture give different visual results
	, test 5,6 and 7,8 show this.
+ 


Draw primitives problems:
note : SDL_RenderDrawRect() bugs are SDL_RenderDrawLines(multiple lines) bugs in reality.

direct3d - windows {
- SDL_RenderDrawRect
	top-left + bottom-left pixels are drawn 2 times
}
software - all {
- SDL_RenderDrawLine
	1 pixel lines are not drawn
}
opengl(es2) - debian 8 {
- SDL_RenderDrawLine
	1 pixel lines are not drawn (gles2 does draw them)
- SDL_RenderDrawRect
	bottom-left pixel is drawn 2 times
	bottom-right pixel is NOT always drawn
}
all - renderers - tested {
- SDL_RenderDrawRect
	0*0 width/height draws a negative 2*2 rectangle
	1*1 width/height is not drawn
+ SDL_RenderDrawRect() probably needs a few special checks...
}

I missed a few :


software render + SDL_RenderFillRect
	A w or h with 0 will always MAX() up to 1 - SW_RenderFillRects() uses MAX(w/h,1)
	, tests 1 and 2 show this

software render + viewport + clip-rect
	It seems the software renderer is using SDL_SetClipRect(), to set the viewport
	, this results in broken behavior if the clip-rect is used in combination with a viewport.
	, adding any draw call after the clip-rectangle usage in the test file, will ignore viewport settings and draw anywhere.

Bug #3324 has a patch to fix the SDL_RenderReadPixels problem with software renderer.