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Anyone here familiar with DirectX?
- Thread starter Ecrofirt
- Start date
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Here's the thing that's really bugging me now.
Those three are dimensioned, and then later on, this happens:
Where ddsd2 has values set to ddsd3's values. The problem is, before this, there is no mention of ddsd3 anywhere in the code. And the tutorial program (which this is copied from) works, which leaves me baffled.
Code:
Dim ddsd1 As DDSURFACEDESC2 [B]'this describes the primary surface[/B]
Dim ddsd2 As DDSURFACEDESC2 [B]'this describes the bitmap that we load[/B]
Dim ddsd3 As DDSURFACEDESC2 [B]'this describes the size of the screen[/B]
Code:
[B]'load the bitmap into a surface - backdrop.bmp[/B]
ddsd2.lFlags = DDSD_CAPS Or DDSD_HEIGHT Or DDSD_WIDTH [B]'default flags[/B]
ddsd2.ddsCaps.lCaps = DDSCAPS_OFFSCREENPLAIN
[B]'An offscreenplain means that
'the user never actually gets to see the surface - it is just an are in memory.[/B]
ddsd2.lWidth = ddsd3.lWidth [B]'the ddsd3 structure already holds the size
'of the screen. We could replace it with 640 and 480 - it would have the same effect[/B]
ddsd2.lHeight = ddsd3.lHeight
[B]'this is where the surface is created. You use the DDraw object to create a
'surface from the specified file name using the above description.[/B]www.directx4vb.com article
the only other spot where I see ddsd3 before what I pasted is here:
Maybe that's it, and I just don't understand it enough. It lookes to me like it's getting the surface description from ddsd3, but ddsd3 hasn't had anything done to it yet.
this is at the beginning of the initialization of the program.
the only other spot where I see ddsd3 before what I pasted is here:
Code:
[B]'get the screen surface and create a back buffer too[/B]
ddsd1.lFlags = DDSD_CAPS Or DDSD_BACKBUFFERCOUNT
ddsd1.ddsCaps.lCaps = DDSCAPS_PRIMARYSURFACE Or DDSCAPS_FLIP Or DDSCAPS_COMPLEX
ddsd1.lBackBufferCount = 1
Set primary = dd.CreateSurface(ddsd1)
[B]'Get the backbuffer[/B]
Dim caps As DDSCAPS2
caps.lCaps = DDSCAPS_BACKBUFFER
Set backbuffer = primary.GetAttachedSurface(caps)
[I]backbuffer.GetSurfaceDesc ddsd3[/I]Maybe that's it, and I just don't understand it enough. It lookes to me like it's getting the surface description from ddsd3, but ddsd3 hasn't had anything done to it yet.
this is at the beginning of the initialization of the program.
Well actually since ddsd2 is the description for the bitmap you load, it doesnt really matter what you set its height/widht initially depending on how you do it. A lot of examples load the bitmap with the GDI functions, read the width and height from there and the description gets set from there when you do that.
Thats what might be happening in the example ur looking at.
Thats what might be happening in the example ur looking at.
Found it:
http://msdn.microsoft.com/archive/en-us/ddraw7/directdraw7/vbddref_77tu.asp?frame=true
BTW, I would seriously suggest you skip DX7.
The DX7 interfaces are totally obsolete now, you'd be much better off learning DX9 instead. Use VB.NET or C#.NET instead. (Or if you want to go older-school, plain old C
).
http://msdn.microsoft.com/archive/en-us/ddraw7/directdraw7/vbddref_77tu.asp?frame=true
BTW, I would seriously suggest you skip DX7.
The DX7 interfaces are totally obsolete now, you'd be much better off learning DX9 instead. Use VB.NET or C#.NET instead. (Or if you want to go older-school, plain old C
).DaMan121 said:Havent followed it much, but I dont think DirectDraw stuff has changed since 7, so if he is only screwin around with that, theres not much use for 9... until he starts on shaders that is
DirectDraw is obsolete. They stopped supporting it after DX7.
MS merged DirectDraw and D3D in DX8, it's just called DirectX Graphics now and handles both 2D and 3D.
So I think he might as well just skip to DX9.
Ecrofirt, directraw may very well be sufficient for what you are doing.
If all you're doing is a 2d game then all you need is access to the frame buffer and the ability to copy bits around. No need to burden yourself with 3d concepts in order to do simpe things.
If you need direct, unimpeded access to the frame buffer directdraw (of which 7 is the last version) is all you've got so I'd hardly call it obsolete.
Unfortunately, I can't help you directly with the VB stuff.
If all you're doing is a 2d game then all you need is access to the frame buffer and the ability to copy bits around. No need to burden yourself with 3d concepts in order to do simpe things.
If you need direct, unimpeded access to the frame buffer directdraw (of which 7 is the last version) is all you've got so I'd hardly call it obsolete.
Unfortunately, I can't help you directly with the VB stuff.
aaaaa0 said:Ya, it was (more or less) conceived of when all a video card could reliably do, was give you a framebuffer.
To be sure, but it's still really weird that no effort was ever put into making it more useful until they merged it with d3d, finally. I guess it just wasn't high priority enough.
Diffense said:
DirectDraw is obsolete. Everything that you can do with DirectDraw, you can pretty much do better with DX9.
If you just want CPU driven access to the frame buffer, just setup your swap chain, grab the back buffer from DX, LockRect(), and party on. (No you can't get access to the front buffer, but why would you want to? That would just cause flickering when you update anything.)
If you want to do something more sophisticated with sprites you can use ID3DXSprite if you want. It will handle all the state setting and stuff for you, and basically emulates 2D blits with 3D. As a side benefit, everything works much faster.
The only tradeoff is the code is a bit more complicated.
I still think he's better off just learning DX9.
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