Help making an image with a memblock?

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Broken_Code

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Location: Bremen, Germany

Posted: 31st Aug 2012 03:35

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Hello,

Ok, so I'm using 'SYNCAIDIUS' MEMBLOCK IMAGE MANIPULATION LIBRARY V1.1' (which is really good if you haven't seen it) to make an image then manipulating the image and applying it to an object as a texture.

The problem:
When I make an image with a memblock it has a thin white line down the right and along the bottom sides (Pic. attached).

This is the code:

+ Code Snippet

Global ResultTexture
 	ResultTexture = IMG_MAKE(Size,Size,RGB(255,0,0))
 	make image from memblock 9,ResultTexture
 	save image "test.jpg",9

Which uses this command from Syncaidius' library:

+ Code Snippet

//Creates a new memblock image filled with the specified colour. 
function IMG_MAKE(width as integer, height as integer, colour as dword) 
   mem = FREE_MEMBLOCK() 
    
   pixels = width*height
   bytes = 4+4+4+(pixels*4) //width+height+depth+data 
   bytePos = 0 
    
   make memblock mem,bytes 
   width = (0<<24) + (0<<16) + (0<<8) + width 
   height = (0<<24) + (0<<16) + (0<<8) + height 
   depth = (0<<24) + (0<<16) + (0<<8) + 32 
    
   //write image info 
   write memblock dword mem,bytePos,width : inc bytePos,4 
   write memblock dword mem,bytePos,height : inc bytePos,4 
   write memblock dword mem,bytePos,depth : inc bytePos,4 
    
   //set every pixel in the image to the specified colour 
   for pixel = 1 to pixels 
      write memblock dword mem,bytePos,colour : inc bytePos,4 //set all pixels to the specified 'colour' 
   next pixel 
endfunction mem

I've looked through it again and againg but I can't see a problem anywhere.

Any help appreciated!
Thanks,
BC

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TheComet

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Location: I`m under ur bridge eating ur goatz.

Posted: 31st Aug 2012 11:50

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Not sure why the function does this here:

+ Code Snippet

   make memblock mem,bytes 
   width = (0<<24) + (0<<16) + (0<<8) + width 
   height = (0<<24) + (0<<16) + (0<<8) + height 
   depth = (0<<24) + (0<<16) + (0<<8) + 32

This here should work:

+ Code Snippet

function IMG_MAKE(width as integer, height as integer, colour as dword)

   rem local variables
   local pixels as dword
   local bytePos as dword

   rem calculate pixel count
   pixels = width*height

   rem find a free memblock
   mem = find free memblock() 
    
   rem create the memblock
   make memblock mem , pixels*32 + 12
    
   //write header 
   write memblock dword mem , 0 , width
   write memblock dword mem , 4 , height
   write memblock dword mem , 8 , 32 
    
   //set every pixel in the image to the specified colour
   bytePos = 12
   for pixel = 1 to pixels 
      write memblock dword mem , bytePos , colour : inc bytePos,4 //set all pixels to the specified 'colour' 
   next pixel

endfunction mem

TheComet

"if you don't understand recursion than you probably don't understand recursion." ~Jerico2day

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Broken_Code

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Location: Bremen, Germany

Posted: 31st Aug 2012 16:31 Edited at: 31st Aug 2012 17:47

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Thanks for your code but the image saved is still the same as in the first post. Could there be another problem somewhere?

I made this quick project:

+ Code Snippet

width=128
height=128
depth=32
pixels=width*height

make memblock 1,(pixels*4)+12
write memblock dword 1,0,width
write memblock dword 1,4,height
write memblock dword 1,8,depth

bytepos=12

for pix=1 to pixels
        write memblock dword 1,bytepos,rgb(0,0,0) : inc bytepos,4
next pix

make image from memblock 1,1
save image "image.bmp",1

I can't see any problems with this but I still get a white strip down the right side and along the bottom in the saved image. Is there a problem with 'make image from memblock'?

On a side note, I don't understand what

+ Code Snippet

   make memblock mem,bytes 
   width = (0<<24) + (0<<16) + (0<<8) + width 
   height = (0<<24) + (0<<16) + (0<<8) + height 
   depth = (0<<24) + (0<<16) + (0<<8) + 32

does, can anyone explain it to me?

Edit: Added code.

Thanks,
BC

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Broken_Code

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Posted: 31st Aug 2012 18:46

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OK, I tried this code on another machine, all worked fine the image has no stripes on it, I even ran the same .exe and the image was fine, so now I'm even more confused about that one!

As this is in the same vein and I don't want to start another thread:

When I apply this image to an object as a texture a small part of the image loops and is copied on to the other side of the object at the bottom and left (I'm applying it to a plain made using IanM's 'make object plain' - pic. attached) this happens on both machines. If I fiddle with the UV coords then I still can't get it to go away, it's less than a pixel's offset.

Thanks for the help,
BC

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Kevin Picone

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Location: Australia

Posted: 31st Aug 2012 18:49

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Quote: " can anyone explain it to me? "

That section doesn't actually do anything. << is a bit shift operator. Some people find it easier to understand as bit scrolling operator, same difference. What it does is moves the bits either Left or right (left in this case).

I suspect the problem might be related to SaveImage though, which i vaguely remember some other people having issues with.

Mobile Platforms Are Coming

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Broken_Code

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Posted: 31st Aug 2012 18:54 Edited at: 31st Aug 2012 18:56

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Thanks for that!

It's not a just save image problem though, as it works on my other machine, maybe it's my machine?

The machine it works on is running Win7(32bit) and the one it doesn't work on is running XP(32bit) if that's any help?

Thanks,
BC

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Rudolpho

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Posted: 31st Aug 2012 20:55

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To be honest I don't even see the line on your posted image.
And no, there's nothing in the code that should cause it as far as I can see; such issues might arise when texturing a plain or similar though, in that case it's because the UV coordinates goes a bit too far and either restarts from the beginning or clamps at the last pixel. But that's not the issue here anyway since its a one-colour image and you didn't say you were using plains (or sprites) so I guess you aren't.

Quote: " make memblock mem,bytes width = (0<<24) + (0<<16) + (0<<8) + width height = (0<<24) + (0<<16) + (0<<8) + height depth = (0<<24) + (0<<16) + (0<<8) + 32"

That's pretty confusing, especially since it doesn't limit width, height or depth to a single byte anyway.
As Kevin said it builds a (supposedly) 32-bit value having the 24:th, 16:th and 8:th bits set to 0. But then after that adds another value that might very well overwrite said bits. Also the proper way to do that is to use the bitwise OR operator and not +; with a bitwise or, setting for example 2 twice will still just set bit 2 to 1. Adding 2 twice will of course rather set bit 3 (4), and allow bit 2 to remain set as well if it was previously.

"Why do programmers get Halloween and Christmas mixed up?"

+ Code Snippet

Because Oct(31) = Dec(25)

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Broken_Code

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Posted: 1st Sep 2012 02:41

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Yes, I've discovered that the line only appears on my XP pc and not on win7 pc I've tried it on wheb it's saved to an image.

But when it's applied to an IanM Matrix utils plane, then it copies a tiny bit of the texture from the top and left to the bottom and right sides as if its a UV problem. However, if I use a standard DBP plane then there is no problem. Is there a known issue with texturing an IanM util plane?

Thanks,
BC

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Broken_Code

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Posted: 11th Sep 2012 13:08

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Just in case anyone else has this problem the answer was mipmapping; if you turn off mipmapping and clamp rather than wrap the image it looks perfect. I found this by applying DarkShader's default shader with mipmapping set to 'none' and texture modes set to 'clamp', here's the .fx file, changes marked:

+ Code Snippet

//Untweakables
float4x4 WorldViewProj : WorldViewProjection;

//Resources
texture BaseTex : DIFFUSE < string ResourceName = ""; >;

sampler BaseSamp = sampler_state
	{
		texture = <BaseTex>;
		MipFilter = None;       //Changed
		MinFilter = None;       //Changed
		MagFilter = None;       //Changed
		AddressU  = Clamp;      //Changed
		AddressV  = Clamp;      //Changed
	};

//Structures
struct app_in
{
	float4 pos : POSITION;
	float2 uv : TEXCOORD0;
};

struct vs_out
{
	float4 pos : POSITION;
	float2 uv : TEXCOORD0;
};


//Vertex shader
vs_out DefaultVertexShader( app_in IN )
{
	//Return the normal vertex pos.
	vs_out OUT;
	OUT.pos = mul( IN.pos, WorldViewProj );
	OUT.uv = IN.uv;
	return OUT;
}

//Pixel shader
float4 DefaultPixelShader( vs_out IN ) : COLOR
{
	//Return the diffuse texture
	return tex2D(BaseSamp,IN.uv);
}

//Techniques
technique MyShader
{
	pass p0
	{
		VertexShader = compile vs_1_1 DefaultVertexShader( );
		PixelShader = compile ps_1_1 DefaultPixelShader( );
	}
}

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