Trouble with screen resolution

Problems or feedback about the NO$PSX emulator by Martin Korth
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Jaberwocky
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Trouble with screen resolution

Post by Jaberwocky » November 20th, 2019, 7:53 am

I recently started to get into PSX development and I use the wonderfull NO$PSX emulator to test my iso files. However, I now started with the basic rendering.

I setup the display and draw enviroment like this:

Code: Select all

#define ScreenWidth  320
#define ScreenHeight 240

SetDefDrawEnv(&displayEnv[0].draw, 0,            0, ScreenWidth, ScreenHeight);
SetDefDrawEnv(&displayEnv[1].draw, 0, ScreenHeight, ScreenWidth, ScreenHeight);
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
SetDefDispEnv(&displayEnv[0].disp, 0, ScreenHeight, ScreenWidth, ScreenHeight);
SetDefDispEnv(&displayEnv[1].disp, 0,            0, ScreenWidth, ScreenHeight);
And then I render a simple blue triangle, cutting the screen in half. Running my ISO with NO$PSX I get a resolution of 320x224px for some reason oO The scene itself is centered so the screen is not actually cut a half. I also tried the PSXeven emulator - there I get the right scene and a resolution of 320x240.
Is my NO$PSX configurated incorrectly?

I made screenshots of the output and attach them to this post.
You do not have the required permissions to view the files attached to this post.

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Shadow
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PlayStation Model: H2000/5502

Re: Trouble with screen resolution

Post by Shadow » November 21st, 2019, 1:35 am

You're missing a bunch of other functions to setup the GPU correctly. Best to check the Sony examples :)
Development Console: SCPH-5502 with 8MB RAM, MM3 Modchip, PAL 60 Colour Modification (for NTSC), PSIO Switch Board, DB-9 breakout headers for both RGB and Serial output and an Xplorer with CAETLA 0.34.

PlayStation Development PC: Windows 98 SE, Pentium 3 at 400MHz, 128MB SDRAM, DTL-H2000, DTL-H2010, DTL-H201A, DTL-S2020 (with 4GB SCSI-2 HDD), 21" Sony G420, CD-R burner, 3.25" and 5.25" Floppy Diskette Drives, ZIP 100 Diskette Drive and an IBM Model M keyboard.

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Jaberwocky
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Re: Trouble with screen resolution

Post by Jaberwocky » November 21st, 2019, 6:58 am

Shadow wrote:
November 21st, 2019, 1:35 am
You're missing a bunch of other functions to setup the GPU correctly. Best to check the Sony examples :)
I was missing some functions in my short code snippet - however, I followed your advice and looked into one of the examples, explicit at:
C:\psyq\cdemu\Sample\Basic\main.c

I simply copied that code, removed the CD related stuff and I still have the problem :/ And again, PSXEVEN uses the correct height.

Edit:
I also tried the HIWORLD example from the website - if I go for PAL with a height of 256, I will end with a height of 264, but rendering will take place in a rect with height of 240 @_@
Going for NTSC with 240, I will have the old behaviour again...

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Shadow
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PlayStation Model: H2000/5502

Re: Trouble with screen resolution

Post by Shadow » November 21st, 2019, 9:59 pm

Make sure you're setting interlaced and progressive scan modes correctly per region. You might also need to adjust the offset position.

IE:

Code: Select all

PAL
GsDISPENV.screen.x = -2;
GsDISPENV.screen.y = 16;

NTSC
GsDISPENV.screen.x = 0;
GsDISPENV.screen.y = 6;
Development Console: SCPH-5502 with 8MB RAM, MM3 Modchip, PAL 60 Colour Modification (for NTSC), PSIO Switch Board, DB-9 breakout headers for both RGB and Serial output and an Xplorer with CAETLA 0.34.

PlayStation Development PC: Windows 98 SE, Pentium 3 at 400MHz, 128MB SDRAM, DTL-H2000, DTL-H2010, DTL-H201A, DTL-S2020 (with 4GB SCSI-2 HDD), 21" Sony G420, CD-R burner, 3.25" and 5.25" Floppy Diskette Drives, ZIP 100 Diskette Drive and an IBM Model M keyboard.

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Jaberwocky
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Posts: 10
Joined: October 31st, 2019, 5:53 am

Re: Trouble with screen resolution

Post by Jaberwocky » November 22nd, 2019, 8:39 am

I kept looking into this issue and noticed something... If I go for NTSC and have a height of 240, I noticed that NO$PSX uses a height of 224 instead - well I read in a function description, that monitors do not show the first 8 pixel at the top and the last 8 at the bottom... that would make 16px.
Now... 224px + 16px => 240px
I guess NO$PSX simulates that effect?

But I still don't get 264px when I go for PAL - that makes additional 8px...

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