draw lines, circles, squares on FPGA by mouse and display on

[lexuancong]

hi !
im from vietnam . my english is not good , i hope you can understand
what i say . thanks !
i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.
.....
thanks you so much !

 

[Jean-Marc Lienher]

lexuancong wrote:

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is

The "video controller" section of Opencores has some VGA controllers
source code.
http://opencores.org/projects

There is a line drawing implementation in VHDL.
http://opencores.org/project,graphicsaccelerator

(I've never tried these projects, so I don't know how useful they are.)

Hope this helps,
Jean-Marc
--
http://www.cod5.org

 

[glen herrmannsfeldt]

lexuancong <lexuancong252@gmail.com> wrote:

im from vietnam . my english is not good , i hope you
can understand what i say . thanks !

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.
....

I don't have any code, but the usual VGA display logic takes a
block of memory and writes that out repeatedly. If you don't need
color, write the same to all three outputs.

Then you have to figure out how to get the shapes drawn into memory.

As it doesn't change, easiest is to load it in a a constant (ROM)
that you have to somehow generate. You can write a ROM initialization
table in any language, then translate that to verilog.

But first you need the display logic. You need a high speed
clock, a row counter, and column counter. You need to generate
the syncronization pulses of the appropriate width and length.

That is as close as I can give now.

-- glen

 

[Tim Wescott]

On Wed, 02 Nov 2011 00:25:33 -0700, lexuancong wrote:

hi !
im from vietnam . my english is not good , i hope you can understand
what i say . thanks !
i have project to graduate university . my project is draw circle , line
, triagle in FPGA , display on VGA ( only use verilog , don't use C) . i
have many problems , and time is running out . if you have data , code
about it , please help me. ....
thanks you so much !

First get your FPGA so that it generates valid VGA sync signals (and a
pixel clock, if VGA needs that). Once you've done that, then do some bog-
simple thing with your pixel generator, like putting out eight white
pixels followed by eight black ones -- that should give you vertical
stripes on the screen, to show progress. Then figure out how to read
pixels out of memory. Finally, stuff the memory with your circles, lines
and squares.

Do you have any friends in the class who are similarly bogged down?
Helping one another isn't a bad idea.

I don't know how your prof is planning on grading things, but if this
were a US university, getting partial functionality is going to be better
than nothing -- a C isn't as good as an A, but it's a lot better than a D
or an F!

--
www.wescottdesign.com

 

[Frank Buss]

lexuancong wrote:

my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.

I have implemented a VGA signal generator, line drawing and bit-blitting
in VHDL:

http://www.frank-buss.de/yagraphcon/index.html

You could take a look at it, try to understand how it works (with
ModelSim you can even single-step the VHDL code and watching how the
registers changes) and then try to implement it yourself in Verilog. For
circles there is a modified Bresenham algorithm. Triangles are trivial,
if you don't need to fill it. If you need filled polygons, it gets a bit
more interesting.

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

 

On Wednesday, 2 November 2011 17:25:33 UTC+10, lexuancong wrote:

hi !

im from vietnam . my english is not good , i hope you can understand

what i say . thanks !

i have project to graduate university .

my project is draw circle , line , triagle in FPGA , display on VGA

( only use verilog , don't use C) . i have many problems , and time is

running out . if you have data , code about it , please help me.

....

thanks you so much !

Hi I am in the same situation with the same project. can u please help me

 

[Herbert Kleebauer]

On 16.10.2013 09:39, ajbhavana89@gmail.com wrote:

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.

Hi I am in the same situation with the same project. can u please help me

Implement a simple CPU on the FPGA and do the drawing
in software.

 

[glen herrmannsfeldt]

ajbhavana89@gmail.com wrote:
> On Wednesday, 2 November 2011 17:25:33 UTC+10, lexuancong wrote:

(snip)

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.

The usual way to run a VGA display is in raster mode reading from
a display RAM. First write the code for that.

Then write code to load the appropriate shapes into memory.
(First clear it to background color.)

That should be a relatively simple state machine, though the easier
way is probably to build a simple processor and execute compiled
C code. (Or some other language.)

-- glen

 

[Adam Górski]

W dniu 2013-10-16 13:10, Herbert Kleebauer pisze:

On 16.10.2013 09:39, ajbhavana89@gmail.com wrote:

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.

Hi I am in the same situation with the same project. can u please help me

Implement a simple CPU on the FPGA and do the drawing
in software.

Have fun.

Adam

 

[Mawa_fugo]

On Wednesday, November 2, 2011 2:25:33 AM UTC-5, lexuancong wrote:

hi !

im from vietnam . my english is not good , i hope you can understand

what i say . thanks !

i have project to graduate university .

my project is draw circle , line , triagle in FPGA , display on VGA

( only use verilog , don't use C) . i have many problems , and time is

running out . if you have data , code about it , please help me.

....

thanks you so much !

I think you need to turn in code, diagram, all in paper right?

If so you can do searchig on net, some folks here are really good help

On the basic, you need a cpu, a video frame buffer (sram, sdram, ...) that can hold let say 640 x 480 pixels vga...
And your FPGA is the center of this project, you use the fpga to glue all together and to make them to work

The cpu somehow needs to take the mouse input to generate pixel data and write it to the buffer

On the other hand, the FPGA has to read the data out from the buffer in raster manner and display it on screen

anyway, this sounds a big project if you do it all by yourself, unless you already had some support

your professor must be the first one to ask...what have he taught you, what hints he can suggest, what evaluation board available etc...

 

[Joseph H Allen]

In article <l3uk42$58i$1@speranza.aioe.org>,
glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:

ajbhavana89@gmail.com wrote:
On Wednesday, 2 November 2011 17:25:33 UTC+10, lexuancong wrote:

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.

The usual way to run a VGA display is in raster mode reading from
a display RAM. First write the code for that.

Then write code to load the appropriate shapes into memory.
(First clear it to background color.)

That should be a relatively simple state machine, though the easier
way is probably to build a simple processor and execute compiled
C code. (Or some other language.)

Overkill.. the video memory can be a ROM preloaded with the video image. The
ROM is just a big case statement (the tools will infer a ROM). Use
run-length coding so that it will fit on the chip (avoiding external memory
interface, allowing it to work on small parts). I think it's just about 100
lines of code.

endmodule
--
/* jhallen@world.std.com AB1GO */ /* Joseph H. Allen */
int a[1817];main(z,p,q,r){for(p=80;q+p-80;p-=2*a[p])for(z=9;z--q=3&(r=time(0)
+r*57)/7,q=q?q-1?q-2?1-p%79?-1:0%79-77?1:0<1659?79:0>158?-79:0,q?!a[p+q*2
]?a[p+=a[p+=q]=q]=q:0:0;for(;q++-1817printf(q%79?"%c":"%c\n"," #"[!a[q-1]]);}

 

[glen herrmannsfeldt]

Mawa_fugo <ccon67@netscape.net> wrote:
> On Wednesday, November 2, 2011 2:25:33 AM UTC-5, lexuancong wrote:

(snip)

i have project to graduate university .
my project is draw circle , line , triagle in FPGA , display on VGA
( only use verilog , don't use C) . i have many problems , and time is
running out . if you have data , code about it , please help me.

(snip)

I think you need to turn in code, diagram, all in paper right?

If so you can do searchig on net, some folks here are really
good help

On the basic, you need a cpu, a video frame buffer (sram,
sdram, ...) that can hold let say 640 x 480 pixels vga...
And your FPGA is the center of this project, you use the fpga
to glue all together and to make them to work

The cpu somehow needs to take the mouse input to generate pixel
data and write it to the buffer

The OP didn't say how the shapes got into memory, just that they
were there. One could just build the logic to generate them and
store them on start up.

On the other hand, the FPGA has to read the data out from the
buffer in raster manner and display it on screen

Well, another way is to generate the bits without storing them.
(Closer to how it was done years ago.)

Say you wanted to just draw a rectangle on the screen. You could
store the top and bottom scan rows, and left and right positions
in the row. Then run row and column counters, and when they are
between the appropriate values, output white, otherwise black.

That doesn't take so much logic, so you can do a few of them.
Not a lot more logic will get you a Pong game from years ago.

Generating a circle that way is a little more work, but not an
impossible amount. Triangles and trapezoids, not so hard.

anyway, this sounds a big project if you do it all by yourself,
unless you already had some support

your professor must be the first one to ask...what have he
taught you, what hints he can suggest, what evaluation board
available etc...

-- glen

 

[Mawa_fugo]

On Saturday, October 19, 2013 9:06:50 PM UTC-5, glen herrmannsfeldt wrote:

Mawa_fugo <ccon67@netscape.net> wrote:

On Wednesday, November 2, 2011 2:25:33 AM UTC-5, lexuancong wrote:



(snip)

i have project to graduate university .

my project is draw circle , line , triagle in FPGA , display on VGA

( only use verilog , don't use C) . i have many problems , and time is

running out . if you have data , code about it , please help me.



(snip)



I think you need to turn in code, diagram, all in paper right?



If so you can do searchig on net, some folks here are really

good help



On the basic, you need a cpu, a video frame buffer (sram,

sdram, ...) that can hold let say 640 x 480 pixels vga...

And your FPGA is the center of this project, you use the fpga

to glue all together and to make them to work



The cpu somehow needs to take the mouse input to generate pixel

data and write it to the buffer



The OP didn't say how the shapes got into memory, just that they

were there. One could just build the logic to generate them and

store them on start up.

Ahhhh, you caught me on this, ... btw hello, long time no chat to anyone in this group ...

Anyway, the OP might/might not say that... I read his title twice, and thought that he want to: "draw lines, circles, squares on FPGA by mouse"

I'm still not so sure what he wanna do, just imagine ...when user click the left button on the mouse and make a circle-like movement, on his/her vga screen will then display a circle-liked shape, still not sure it's perfect circle or an egg alike ???

On the other hand, the FPGA has to read the data out from the

buffer in raster manner and display it on screen



Well, another way is to generate the bits without storing them.

(Closer to how it was done years ago.)



Say you wanted to just draw a rectangle on the screen. You could

store the top and bottom scan rows, and left and right positions

in the row. Then run row and column counters, and when they are

between the appropriate values, output white, otherwise black.



That doesn't take so much logic, so you can do a few of them.

Not a lot more logic will get you a Pong game from years ago.



Generating a circle that way is a little more work, but not an

impossible amount. Triangles and trapezoids, not so hard.

That's interesting, that you can do the 'direct draw' like that from the logic... the rectangle is piece of cake & pretty easy to understand, ... I wonder how to do that for other shapes like you said ?

anyway, this sounds a big project if you do it all by yourself,

unless you already had some support



your professor must be the first one to ask...what have he

taught you, what hints he can suggest, what evaluation board

available etc...



-- glen

 

[glen herrmannsfeldt]

Mawa_fugo <ccon67@netscape.net> wrote:

On Wednesday, November 2, 2011 2:25:33 AM UTC-5, lexuancong wrote:
(snip)
i have project to graduate university .
my project is draw circle , line , triagle in FPGA ,
display on VGA

(snip, I wrote)

The OP didn't say how the shapes got into memory, just that they
were there. One could just build the logic to generate them and
store them on start up.

Ahhhh, you caught me on this, ... btw hello, long time no chat to
anyone in this group ...

Anyway, the OP might/might not say that... I read his title twice,
and thought that he want to: "draw lines, circles, squares on
FPGA by mouse"

Could be. But just drawing some figures is a not too simple, but also
not too hard project for an introduction to actually building logic.

I'm still not so sure what he wanna do, just imagine ...when user
click the left button on the mouse and make a circle-like
movement, on his/her vga screen will then display a
circle-liked shape, still not sure it's perfect circle or
an egg alike ???

That is pretty tricky to do all in hardware. Well, as a combination
of state machines not so hard to do. One state machine to keep
track of the mouse position, (and generate the cursor), another
to keep track of what the mouse is doing, then some more to draw
the figure. But only after you know how to draw figures.


(snip, I also wrote)

Well, another way is to generate the bits without storing them.
(Closer to how it was done years ago.)

Say you wanted to just draw a rectangle on the screen. You could
store the top and bottom scan rows, and left and right positions
in the row. Then run row and column counters, and when they are
between the appropriate values, output white, otherwise black.

That doesn't take so much logic, so you can do a few of them.
Not a lot more logic will get you a Pong game from years ago.

Generating a circle that way is a little more work, but not an
impossible amount. Triangles and trapezoids, not so hard.

That's interesting, that you can do the 'direct draw' like
that from the logic... the rectangle is piece of cake & pretty
easy to understand, ... I wonder how to do that for other
shapes like you said ?

One way is with some form of Bresenham's algorithm. That is
mostly used for drawing lines instead of filled shapes, but
should also work for filled shapes. There is also a related
algorithm for circles.

Another is with a phase accumulator to keep track of the
starting and ending points. Consider a binary value with the
binary point not just after the ones bit, such that it can
hold fractional values. Now, each cycle (scan line) you add
a binary value approximating the slope of the line. The integer
(ignore fractional bits) value is now the starting coordinate
on that scan line. For curved shapes, you could find the start
and end points with some form of CORDIC.

Once you have the start and end points for each scan line, all
you need is the logic to determine inside and outside, and generate
the appropriate output signal.

In the days of expensive computing hardware, it was more usual
to do something like that, though maybe more usual to do it with
analog electronics.

There were some fairly expensive vector graphics systems that
continually refreshed the display from a display buffer.
With the two end points of a line segment, some D/A converters,
and some analog circuitry you can generate the X and Y values
long a line segment. Charge two capacitors with the appropriate
currents, and the voltage as a function of time will be reasonably
linear.

Then there were the Tektronix terminals based on storage CRTs,
as developed for oscilloscopes. The image is stored as charge on
the screen.

-- glen

 

[Nikolaos Kavvadias]

Hi all,

to the OP: you can examine PLOTLINE and PLOTCIRCLE, two demo IPs by Ajax Compilers (http://www.ajaxcompilers.com). They come for FREE, just register to the Ajax Compilers store. They are ZERO EURO, no cost, totally free IPs, just give them a shot. They come with reasonable documentation and a demo platform setup for a Spartan-3AN starter kit FPGA board!

If you are in a hurry, I have another version for the Bresenham line drawing function here: http://www.nkavvadias.com/hercules/ (scroll down, there are lots of other materials on high-level synthesis there). It is called "linedraw" there.

In short, I have used pure C code implementations for both the line and circle drawing algorithms, and then passed them through HercuLeS (my HLS tool).. It is purely automated work, no hand coding please, this is 2013 and I'm an EDA tool developer (LOL)

I also have lots of other graphics primitives stuff, like an ellipse algorithm, etc. I don't recall having implemented a flood filler in hardware. I think you can do better than iteratively running Bresenham's algorithm. If you do this, you will have to make a second pass, patching untouched pixels (this is what it looks like at first glance).

Hope these help.

Best regards,
Nikolaos Kavvadias
http://www.nkavvadias.com

 

[Mike Perkins]

On 16/10/2013 08:39, ajbhavana89@gmail.com wrote:

On Wednesday, 2 November 2011 17:25:33 UTC+10, lexuancong wrote:
hi !

im from vietnam . my english is not good , i hope you can understand

what i say . thanks !

i have project to graduate university .

my project is draw circle , line , triagle in FPGA , display on VGA

( only use verilog , don't use C) . i have many problems , and time is

running out . if you have data , code about it , please help me.

....

thanks you so much !

Hi I am in the same situation with the same project. can u please help me

I'm happy to point you in the right direction, but I don't think it's
appropriate to provide code.

In our product I create concentric circles using the Bresenham's circle
algorithm on raster display and is ideal for square pixel formats. It
is possible to vary the theme to make ovals, or even circles on non
square pixel formats.

The algorithm doesn't need a multiplier, but most FPGAs have a wealth of
ALUs such that it might be just as appropriate to calculate squared
numbers using an ALU.

Google will find a number of articles though some are more confusing
than others. I had considered adding an article myself to our website
but just haven't got around to it!


Similarly for drawing lines, have a look at Bresenham's line algorithm,
but that is something I have never used! I've stuck to only drawing
horizontal and vertical lines!


--
Mike Perkins
Video Solutions Ltd
www.videosolutions.ltd.uk

 

[Adam Górski]

W dniu 2013-10-16 09:39, ajbhavana89@gmail.com pisze:

On Wednesday, 2 November 2011 17:25:33 UTC+10, lexuancong wrote:
hi !

im from vietnam . my english is not good , i hope you can understand

what i say . thanks !

i have project to graduate university .

my project is draw circle , line , triagle in FPGA , display on VGA

( only use verilog , don't use C) . i have many problems , and time is

running out . if you have data , code about it , please help me.

....

thanks you so much !

Hi I am in the same situation with the same project. can u please help me

There is wrong topic.
It is more like "Do my homwork for free" not "help me understand my
problem "
Don't u see !?

Adam

 

[GaborSzakacs]

Adam Górski wrote:

W dniu 2013-10-16 09:39, ajbhavana89@gmail.com pisze:
On Wednesday, 2 November 2011 17:25:33 UTC+10, lexuancong wrote:
hi !

im from vietnam . my english is not good , i hope you can understand

what i say . thanks !

i have project to graduate university .

my project is draw circle , line , triagle in FPGA , display on VGA

( only use verilog , don't use C) . i have many problems , and time is

running out . if you have data , code about it , please help me.

....

thanks you so much !

Hi I am in the same situation with the same project. can u please help me


There is wrong topic.
It is more like "Do my homwork for free" not "help me understand my
problem "
Don't u see !?

Adam

Probably a moot point as the original post came two weeks ago and the
OP has disappeared since then. This seems typical of the "do my work
for me" threads. While the community has fun discussing possibilities,
the original poster has missed his deadline and is now flipping burgers.

--
Gabor