My first overlay - 4:3 CRT @720p for integer scaling

[amartinr]

Hi,

First of all, a ton of thanks to the RetroPie and Retroarch community. You guys are awesome! I've been somewhat of a lurker and I thought it was about time to share my experience.

Lately, I've been playing around with video modes, shaders and overlays. My TV set is 1080p capable, but I wanted to give 720p a try, even though I haven't noticed any performance nor overheating issues.

I started experimenting with lr-nestopia and realized that 720 is 3 times 240, so I thought that'd make a perfect match when using integer scaling. Trying to be faithful to 4:3 aspect ratio I decided to configure NES emulation (lr-nestopia) to use 1024x720, since 256 x 4 = 1024.

aspect_ratio_index = "22"
## 8:7 pixel ratio
#custom_viewport_width = 822
## 4:3 pixel ratio
#custom_viewport_width = 960
# nearest multiple of native width (256*4x240*3)
custom_viewport_width = 1024
custom_viewport_height = 720

The problem is that I wasn't happy with the appearance of crt-pi shaders at 720p, so I tried to build an overlay to mimic old CRTs. Since I decided to use 4:3 and integer scaling, let's say that 1 pixel is actually a 4x3-pixel matrix, so I created a pattern trying to emulate RGB pixels (the following image is upscaled).

The resulting overlay for 1024x720 looks like this:

Here are some photos of the final result:

What do you think? Could I get better results with a different position of pixels in my pattern?