Re: Transparent rectangle in GDI [modified] - Graphics Discussion Boards

KaldaP3-Nov-08 9:35

3-Nov-08 9:35

Hello!

As the topic says, I have another problem with my DirectShow filter...
It works fine in all players on xp and vista except WMP11 for Vista (under XP works)...
Have You any idea? Thanks

origami

migraine2-Nov-08 3:06

migraine

2-Nov-08 3:06

i want to create a small program for any object of "origami" using C++ and opengl....i dont have any idea...i m a learner.......can anyone send me a source code for any object of origami

Re: origami

Tim Craig2-Nov-08 16:58

Tim Craig

2-Nov-08 16:58

Something wrong with the 322,000 examples a simple Google search turns up?

Your silly assed, irrelevant opinion has been duly noted. Now take it elsewhere!

Re: origami

Smithers-Jones5-Nov-08 0:26

Smithers-Jones

5-Nov-08 0:26

Hours and hours of endless research on the internet finally revealed the following result:
TreeMaker 5 (source included)[^]

Just kidding, 3 seconds with Google and I found it. Maybe you should first learn, how to use Google?

Transparent rectangle in GDI

Heptagonal1-Nov-08 13:17

Heptagonal

1-Nov-08 13:17

Hi,

I've been trying to display a transparent rectangle using standard Win32/GDI coding now for at least an hour. I've searched in tons of places, but I just can't get it working. This is my current code:

RECT r = GetRect(); // That's not really what the function is called, but you get the gist...

HBRUSH brush = CreateSolidBrush(RGB(0x00, 0xD7, 0xEC));	
FillRect(hdc, &r, brush);
DeleteObject(brush);

That displays fine, but it displays a completely opaque rectangle and I'm clueless on how to go about making it transparent.

Any help is very much appreciated!
Thanks,
Martin

Re: Transparent rectangle in GDI

Perspx1-Nov-08 13:54

Perspx

1-Nov-08 13:54

I wouldn't recommend using GDI for transparency - it wasn't designed to accommodate such features.

Instead, I'd take a look at GDI+, an extension of the GDI library and is included with versions of Windows XP upwards, but can also be distributed as an executable with your app if the target OS is lower than this. It's also a good library to familiarise yourself with for the future due to its diverse graphics manipulation functions included.

Something like this could create a semi-transparent black rectangle:

SolidBrush solidBrush(Color(150, 0, 0, 0)); //Color format: Alpha, R, G, B
graphics.FillRectangle(&solidBrush, 0, 0, 100, 50); //brush, x, y, width, height

Take a look more at the SolidBrush() class, the FillRectangle() method.

Regards,
--Perspx

"I've got my kids brainwashed: You don't use Google, and you don't use an iPod." - Steve Ballmer

"Some people have told me they don't think a fat penguin really embodies the grace of Linux, which just tells me they have never seen an angry penguin charging at them in excess of 100mph." - Linus Torvalds

Re: Transparent rectangle in GDI

Heptagonal1-Nov-08 21:58

Heptagonal

1-Nov-08 21:58

Thanks, I'll check it out.

Re: Transparent rectangle in GDI [modified]

Mark Salsbery1-Nov-08 16:05

Mark Salsbery

1-Nov-08 16:05

ummm....you are explicitly creating an opaque brush and then filling
a rect with it. There's nothing transparent about any of that Smile | :)

If you are trying to draw a hollow rect...

//untested - hopefully no typos :)

HPEN pen = CreatePen(PS_SOLID, 1, RGB(0x00, 0xD7, 0xEC));
HGDIOBJ oldpen = SelectObject(hdc, pen);
HGDIOBJ oldbrush = SelectObject(hdc, GetStockObject(HOLLOW_BRUSH));
Rectangle(hdc, r.left, r.top, r.right, r.bottom);
SelectObject(hdc, oldpen);
SelectObject(hdc, oldbrush);
DeleteObject(pen);

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

modified on Saturday, November 1, 2008 10:12 PM

CImg

jarabu30-Oct-08 17:27

jarabu

30-Oct-08 17:27

I've downloaded the Cimge library (for mac) but can' compile it. I've tried different versions
Compile for Linux/BSD/MacOSX, with X11 display and standard options.
Compile for Linux/BSD/MacOSX, with X11 display and debug informations.
Compile for Linux/BSD/MacOSX, with X11 display and optimizations.
Compile for Linus/BSD/MacOSX, with minimal dependancies.
Compile for Linux/BSD/MacOSX, with maximal dependancies.

but dosen't seems to work.

Can anyone help me please

Thanks a lot
Confused | :confused:

TCL\TK openGL

pallaka28-Oct-08 22:52

pallaka

28-Oct-08 22:52

Hi

How can i use TCL\TK for openGL?
Do anybody have any learning material?

OpenCV

ramvvs22-Oct-08 22:51

ramvvs

22-Oct-08 22:51

anyone there who is an expert in Opencv? and Image Processing using C?

Phaniram vvs

Re: OpenCV [modified]

Tim Craig23-Oct-08 19:26

Tim Craig

23-Oct-08 19:26

I know something about OpenCV. Do you have a specific question?

[added 10/27/08]

Guess that was a rhetorical question. D'Oh! | :doh:

Your silly assed, irrelevant opinion has been duly noted. Now take it elsewhere!

modified on Tuesday, October 28, 2008 1:33 AM

OpenGL, DirectDraw or Direct3D

Running Fool22-Oct-08 12:03

Running Fool

22-Oct-08 12:03

I need to create a visualization of the progress of machining a part. The part is a relatively simple shape made up of cylinders and conical sections and only a side 2D view, no texture and minimal if any shading, for now. I will have to put the graphic in an ActiveX control or VBA form. This is my first time going beyond the MFC-GDI and am wondering what direction to start in and why.

Thanks in Advance

opengl, loading picture on the surface.

rkata20-Oct-08 4:47

rkata

20-Oct-08 4:47

Hi all!
Please help me with my question. I'd like to draw .bmp file on openGL surface. My openGL surface is GL_TRIANGLE_STRIP set. Now I can load bitmap on the surface but it is not I want. Now I'm receiving the surface with tilled images. But I'd like to fit my picture on whole surface.
Thanks.

Muscles in OpenGL

Michael Fritzius18-Oct-08 10:19

Michael Fritzius

18-Oct-08 10:19

Hi all,

I'm trying to find a set of calculations that describe different muscles. My goal is to find some formula that can be tweaked a little bit, so that the dimensions end up looking different. For example, the shoulder muscle--modify one variable and it looks beefier, modify another and it gets wider. Anybody know where I can find some formulas for this kind of thing?

Thanks for your time,
Michael Fritzius

Simple way to learn directx

ripsware16-Oct-08 8:02

ripsware

16-Oct-08 8:02

any one here can teach me how to use directx to drawing using VB.Net

Coz I wana create a Game!!! Confused | :confused:

Re: Simple way to learn directx

KaldaP17-Oct-08 9:29

KaldaP

17-Oct-08 9:29

Hello!
Are You writing 2D or 3D game?

2D: Google for DirectDraw tutorials (fe http://www.falloutsoftware.com/tutorials/dd/dd1.htm)

3D: Direct3D or OpenGl tutorials
http://www.gametutorials.com/gtstore/c-5-directx.aspx
http://nehe.gamedev.net
http://www.swiftless.com/tutorials/opengl/opengltuts.html

And for both try MSDN (msdn.microsoft.com)

P.S.: If you want to buy any book I like this
http://www.amazon.com/Direct3D-Programming-Start-Clayton-Walnum/dp/0672324989/ref=sr_1_5?ie=UTF8&s=books&qid=1224271818&sr=1-5

Re: Simple way to learn directx

ripsware17-Oct-08 9:39

ripsware

17-Oct-08 9:39

Thanks for U're sugestion! Big Grin | :-D

I write 2D game, I try write the game using GDI, but some times the program run slowly! Sniff | :^)

, so I try write the game using direct X, but until now i dont understand about it! Confused | :confused:

Re: Simple way to learn directx

Mark Salsbery18-Oct-08 9:20

Mark Salsbery

18-Oct-08 9:20

rio_p wrote:
using direct X, but until now i dont understand about it!

If you Google "directx VB.NET' you'll find a link to an older DirectX
SDK that has VB.NET samples in it, along with all the DirectX documentation.

You're going to need the DirectX SDK anyway Smile | :)

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: Simple way to learn directx

quakeboy29-Oct-08 0:04

quakeboy

29-Oct-08 0:04

I suggest you learn SDL.. its fast, portable.. and easy to learn

I made a tetris game using it. It was amazing to look at your game run both on windows and linux...

DirectX/DirectDraw is good... but I think SDL is better for your needs, most 2D needs. and you can even do 3D by mixing OpenGL with it.

drawing a room

guyadika15-Oct-08 10:19

guyadika

15-Oct-08 10:19

hi all

i'm new in graphics...

i want to build a small 2d module of my room, with all the closets and tables...

but i dont know where to start...

is it to much more difficult the draw a 3d module???

i will appreciate if you can guide me

Re: drawing a room

guyadika15-Oct-08 10:20

guyadika

15-Oct-08 10:20

by the way... i'm writing in c#

Re: drawing a room

Alan Balkany16-Oct-08 3:45

Alan Balkany

16-Oct-08 3:45

2D is easy, 3D is harder. You should start with 2D to get the initial programming and graphics issues resolved in an easy context.

After 2D is working, adapt it to 3D. The key concept you'll need is called the Viewing Transformation: http://www.idav.ucdavis.edu/education/GraphicsNotes/Viewing-Transformation/Viewing-Transformation.html[^]

It looks harder than it is. You can ignore the (complex) derivation, and just use the final matrix to transform your 3D room coordinates to 2D screen coordinates.

Extrapolating lines to fill in missing sections

Keith (MapMan)15-Oct-08 6:09

Keith (MapMan)

15-Oct-08 6:09

I am trying to write some code to reconstruct a small irregular shaped "hole" in an image where the image data has been lost. My hope is that by analysing the surrounding image I can make an intelligent guesses as to what the missing part might look like.

Using standard edge recognition techniques I have managed to identify strong contrast edges in the surrounding image. The next step is to identify which of these edge lines cross the hole and to extrapolate them across.

The image at http://www.bracknellbridge.com/images/Thinned1.bmp[] shows where I'm at. The dark surround represents part of the image for which data is intact and the light grey centre is the area I am trying to reconstruct. The white line segment above and below the light grey area represents a high contrast edge. To the human eye it looks like this line probably crosses the light grey area. What I need is a general algorithm to recognise this situation and extrapolate the line across the hole.

It has been suggested that the Hough transform might be the way to go but I'm struggling with how to apply this in a practical sense. Is the idea to consider every possible pair of points and calculate the parametric equation of the line passing through them, then see which values are most common?

It sounds simple in theory but I can think of practical problems. If points A and B are on line 1 which is very close, but not identical, to line 2 which joins C and D how can I ensure they are interpreted as 2 votes for "nearly" the same line? How close is close enough?

If anyone has some practical advice or ideas I should be very interested. A practical code example of the Hough transform would be especially useful.

Keith

Re: Extrapolating lines to fill in missing sections

Alan Balkany16-Oct-08 3:59

Alan Balkany

16-Oct-08 3:59

Indirectly you do consider every possible pair of points, but algorithmically it's a bit simpler.

Start with an array representing the unknown region, initiallized to all zeroes. Then go through each known point in the original image, and if it's white, trace out line segments in your array that go through this point (at different angles), incrementing the array elements each line intersects.

You'll get a lot of "noise", but the highest values in the array will be along the missing segment because all the known white points will combine their "votes" along this line.

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