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Bug 780 - Rendering platform differences
Summary: Rendering platform differences
Status: RESOLVED FIXED
Alias: None
Product: SDL
Classification: Unclassified
Component: video (show other bugs)
Version: HG 2.0
Hardware: x86 All
: P2 normal
Assignee: Sam Lantinga
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-08-13 07:31 UTC by Mike
Modified: 2009-12-14 12:12 UTC (History)
0 users

See Also:

Attachments
Sample program (3.05 KB, text/plain)
2009-08-13 07:31 UTC, Mike 		Details
Snapshot on Linux (5.61 KB, image/png)
2009-08-13 07:33 UTC, Mike 		Details
Snapshot on Vista (8.70 KB, image/png)
2009-08-13 07:33 UTC, Mike 		Details
Snapshot on XP (6.94 KB, image/png)
2009-08-13 07:34 UTC, Mike 		Details
Line rendering difference (16.57 KB, image/png)
2009-10-14 03:37 UTC, Mike 		Details
Sample program: line rendering - one pixel difference demo (2.82 KB, text/x-csrc)
2009-10-14 03:40 UTC, Mike 		Details
View All Add an attachment (proposed patch, testcase, etc.)

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Description Mike 2009-08-13 07:31:07 UTC 
Created attachment 345 [details]
Sample program

SDL_RenderLine() and SDL_RenderFill() are mismatch in the reference grid.
I've attached a listing of the program that draws a cross, using both this functions, in the same coordinates.
Linux:
   one "extra" pixel at the bottom and right for SDL_RenderLine()
Windows:
   both XP and Vista has shifting to one pixel to right-bottom for SDL_RenderFill() against SDL_RenderLine().
Comment 1 Mike 2009-08-13 07:33:18 UTC 
Created attachment 346 [details]
Snapshot on Linux
Comment 2 Mike 2009-08-13 07:33:58 UTC 
Created attachment 347 [details]
Snapshot on Vista
Comment 3 Mike 2009-08-13 07:34:46 UTC 
Created attachment 348 [details]
Snapshot on XP
Comment 4 Sam Lantinga 2009-09-26 03:33:34 UTC 
Can you retest with the current SDL snapshot?
http://www.libsdl.org/tmp/SDL-1.3.zip

Thanks!
Comment 5 Mike 2009-10-14 03:34:35 UTC 
Expecting that
{{{
	SDL_SetRenderDrawColor(255, 0, 0, SDL_ALPHA_OPAQUE);
	SDL_RenderPoint(point1X, point1Y);
	SDL_RenderPoint(point2X, point2Y);

	SDL_SetRenderDrawColor(255, 255, 0, SDL_ALPHA_OPAQUE);
	SDL_RenderLine(point1X, point1Y, point2X, point2Y);
}}}
works similar, but for linux a line covers both points, for win32 - only one: top (for vertical lines) or left (for horizontal).

Linux: software renderer
Win32: D3D renderer

Tested with SDL-1.3.0-5097 snapshot.
Attaching an image for comparison and code of the test program
Comment 6 Mike 2009-10-14 03:37:41 UTC 
Created attachment 416 [details]
Line rendering difference
Comment 7 Mike 2009-10-14 03:40:04 UTC 
Created attachment 417 [details]
Sample program: line rendering - one pixel difference demo
Comment 8 Sam Lantinga 2009-10-16 21:04:45 UTC 
Thanks, I'll take a look at this after I get the 1.2 release wrapped up.
Comment 9 Sam Lantinga 2009-12-13 23:01:49 UTC 
Whew, it took a while, but I've got the automated tests working and fixed lots of problems with the line rendering on various platforms.

Can you try in the latest snapshot?
http://www.libsdl.org/tmp/SDL-1.3.zip

Thanks!
Comment 10 Mike 2009-12-14 03:27:10 UTC 
The issue was solved!

Thanks!
Comment 11 Sam Lantinga 2009-12-14 12:12:47 UTC 
Yay, thanks!