help to create picture on memory and display on vga monitor

hi,
i am working on CYCLONE -II fpga devlopment boad, i am trying to implement opengl on FPGA for my final year project, now i am working on the output part i tried to display some picture on monitor , now problem i am facing is


1)i dont know how to use memory to create image

2)i am not able to create my own image on my memory(e.g creating some box, some triangle, square )

please suggest me how to do or which site i need to go..........
thanks in advance.

Re: help to create picture on memory and display on vga moni

I cannot help you much with this, but can give some clues as I am working with video and ram video right now.

To display some picture on video, you could use a ROM with the pattern. For altera, this can be acomplished defining some .mif file with the content of the ROM. For example:

Depth = 512;
Width = 8;
Address_radix = oct;
Data_radix = bin;
% Character Generator ROM Data %
Content
Begin
010 : 00011000 ; %---**----%
011 : 00111100 ; %--****--%
012 : 01100110 ; %-**--**-%
013 : 01111110 ; %-******-%
014 : 01100110 ; %-**--**-%
015 : 01100110 ; %-**--**-%
016 : 01100110 ; %-**--**-%
017 : 00000000 ; %---------%

Click to expand...

To generate your own graphics, you may generate the pixels (bits) first in a RAM memory.

To show text characters on video, I am using two steps:

1. Generate the character code I want on RAM
2. The VGA controller reads the character code from RAM, calculate the address of the pattern on ROM, and show the pixels on the monitor

This is more or less complex. Very complex for me, because I am beginner with FPGA and VHDL.

But, as long as you proposed to implement OpenGL in a FPGA, I suppose you master graphics concepts.

Keep in mind that, for 3D graphics, you will need a VERY large video ram. The altera dev boards does not have that much RAM...
Any way, wait and see if someone else will give you more information.

Re: help to create picture on memory and display on vga moni

hi,
thanks for reply..... can you give me some more details regarding how you generated character on RAM (what method you used) and how you read that in vga driver ............ if you have any document please provide me it is going help................

thank you

regards
honnaraj

Re: help to create picture on memory and display on vga moni

honnaraj.t said:

hi,
thanks for reply..... can you give me some more details regarding how you generated character on RAM (what method you used) and how you read that in vga driver ............ if you have any document please provide me it is going help................

thank you

regards
honnaraj

Click to expand...

My project is based on the book "Rapid Prototyping of Digital Systems, SOPC EDITION".

They cover all of this, from VGA signal generation to character displays and video ram memory.
You can find a similar project here: **broken link removed**

Regards.

Re: help to create picture on memory and display on vga moni

go to www.fpga4fun.com and take a look at the Pong game example. Shows how to output some basic graphics directly to a vga monitor

Re: help to create picture on memory and display on vga moni

Hi,
just for basic functionality test,
Put high/ low on the RGB lines.
Create a colour pattern of some lines of red,few green and blue.
like generate a band of colours on the display.
With colour pattern first u try to debug...
This is the simplest basic testing for display.