XNA Game Studio 3.0 Unleashed Code updated to Run under Windows 10 (and HoloLens)

I’ve gone through the first pass of updating the code in the book. This took quite a bit of time. Some of the chapters are still a little wonky as I’ve ran out of time. But I wanted to get what I have done out into the public in case it was beneficial to anyone. I never really thought I’d update the code for the XNA Game Studio 3.0 Unleashed book. There were a lot of breaking changes between XNA 3.1 and XNA 4.0 and I just didn’t have the time to do it.

However, with my HoloLens being ordered, and hearing Tom Spilman on .NET Rocks last week (http://www.dotnetrocks.com/?show=1283), I decided to see what it would take to upgrade. It was surprisingly simple to get quite a few chapters converted and upgraded. Other chapters were just not attempted (like Networking stuff that isn’t directly in MonoGame [they expect you to use other libraries]). Others had to be commented out to work (like the GameServices stuff to bring up the Xbox Guide, etc.)

Still, the overall conversion project was a success. There a couple of rough edges, but now anyone can fork it and do what they’d like with it. Feel free to send a pull request, if you smooth out a rough edge. Try to keep with the original intent with the code as much as possible.

Go ahead and grab the code from GitHub:

https://github.com/kewlniss/XNAUnleashed

The Table of Contents for the book this code goes with can be found at http://xnaessentials.com/unleashed

As I’m going through and updating the code I ran into a following snag that took me a bit to figure out. In this case, I only had a Pixel Shader and no Vertex Shader. The shader worked just fine back in the day, but during the upgrade I was told that MonoGame only supported ps_4_0 and this shader was version 1.0 (ps_1_0).  Simply changing the version number in the shader file fixed that.

But then I had a bug where the shader wasn’t giving me the results I wanted.

After poking around a little bit, I finally found out that the method signature needs to explicitly have all of the parameters.  I found this information here:

http://www.software7.com/blog/pitfalls-when-developing-hlsl-shader/

The way my pixel shader looked original was:

sampler TextureSampler;

struct PixelInput
{
    float2 TexCoord : TEXCOORD0;   
};

float4 pixelShader(PixelInput input) : COLOR
{
    float4 color = tex2D( TextureSampler, input.TexCoord);
    return( color );
}

technique Default
{
    pass P0
    {
        PixelShader = compile ps_1_1 pixelShader();
    }
}

And I had to change it to:

sampler TextureSampler;

struct PixelInput
{
    float4 Pos : SV_POSITION;
    float4 Color : COLOR0;
    float2 TexCoord : TEXCOORD0;
};

float4 pixelShader(PixelInput input) : SV_TARGET0
{
    float4 color = tex2D( TextureSampler, input.TexCoord);
    return( color );
}

technique Default
{
    pass P0
    {
        PixelShader = compile ps_4_0 pixelShader();
    }
}

Once I made that small tweak (added in the different parameters (albeit through a struct)) it worked like a charm. A struct doesn’t have to be used, but the parameters should be in the right order it seems – position, then color, then texture coordinates.

Note, that this pixel shader doesn’t do anything but return the pixel of the texture passed to it.  Typically you would do some math on the color before returning it. Check out Chapter 15, under SimpleGame for some different pixel shader examples when I update the code to GitHub. (Before the end of the month…)

So make sure that your pixel shader parameters are all present and associated with the right semantics!