03875: Most/all sets running on Amiga hardware: Visible area one pixel narrower than intended

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
03875	Graphics	Typo	Always	Jun 4, 2010, 22:21	Jun 7, 2010, 11:38

Tester	absence	View Status	Public	Platform
Assigned To		Resolution	Open	OS
Status [?]	Confirmed			Driver
Version	0.138	Fixed in Version		Build
		Fixed in Git Commit		Github Pull Request #

Summary	03875: Most/all sets running on Amiga hardware: Visible area one pixel narrower than intended
Description	The widths of the Amiga based drivers I've checked (haven't looked at all) are strange numbers like 671 and 703. According to this post by Aaron Giles, the visible area is based on numbers in the hardware reference manual and borders that are evenly divisible by eight to account for overscan: http://www.mameworld.info/ubbthreads/showthreaded.php?Cat=&Number=223392&page=0&view=expanded&sb=5&o=&fpart=1&vc=1 The numbers in the manual are 640x256 for PAL hardware and 640x200 for NTSC hardware, meaning the intended widths specified in the drivers are wrong. The following line is from one such driver, based on NTSC hardware: MDRV_SCREEN_VISIBLE_AREA((129-8)2, (449+8-1)2, 44-8, 244+8-1) Since coordinates start at 0, the width and height has to be reduced by 1. But the reduction in the horizontal direction is done before multiplying by two to obtain hires pixels rather than lores ones. The subtraction should take place after the multiplication, like this: MDRV_SCREEN_VISIBLE_AREA((129-8)2, (449+8)2-1, 44-8, 244+8-1) The numbers are different for PAL hardware like the Cubo CD32, but the typo is the same.
Steps To Reproduce
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	Most/all sets running on Amiga hardware

Attached Files

No.06228 robiza Developer Jun 5, 2010, 10:26	normally a PAL amiga use a 640x256 resolution you can get an higher resolution with a trick (you can edit the system-configuration binary file and set the higher resolution) the higher resolution is 703 (not sure vertically) this is not a bug
No.06229 Haze Senior Tester Jun 5, 2010, 13:13	there is a bug.
No.06231 absence Tester Jun 6, 2010, 13:24 edited on: Jun 6, 2010, 13:26	robiza: While there is an unspecified maximum horizontal resolution limited by the hardware, it doesn't make sense for it to be 703, as the data-fetch registers have four-pixel resolution. Also, people have managed to display 740 pixels per scan line. The visible area in each Amiga related MAME driver should probably reflect the actual number of pixels used by each game, as it's likely that the monitor is calibrated to stretch the image to fill the screen (4:3) whatever the resolution is.
No.06232 robiza Developer Jun 6, 2010, 19:52	we have some option: 1) max horizontal resolution (736 pixel) (with the border) 2) the game resolution (fixed resolution) (without the border) 3) overscan handled by the driver (dynanimic resolution) (without the border) for me the right option is the first (maybe we can have a cropped resolution option in the video configuration menu to reflect the actual number of pixels used by each game without the border)
No.06233 absence Tester Jun 6, 2010, 23:14	But how do you know what the maximum resolution is for the first option? http://eab.abime.net/showthread.php?p=565320 shows that it's not a simple question.
No.06234 robiza Developer Jun 7, 2010, 11:38	i know this thread; probably 768 is a better choice i think we can have problem in the mess side if we use the same code for mame and mess for now we can use the cropped resolution