Transform feedback test

Console.WriteLine(GL.GetString(StringName.Vendor));
Console.WriteLine(GL.GetString(StringName.Renderer));
Console.WriteLine(GL.GetString(StringName.Version));
Console.WriteLine(GL.GetString(StringName.ShadingLanguageVersion));

const string shaderSource =
#region source
@"
#version 150

uniform sampler2D accelerationTexture;
uniform float timeDelta;

in vec3 v_position;
in vec3 v_velocity;
in float v_deathTime;
in float v_angle;
in float v_angleVelocity;
in vec2 v_size;
in vec2 v_uv00;
in vec2 v_uv10;
in vec2 v_uv01;
in vec2 v_uv11;
in vec3 v_unitX;
in vec3 v_unitY;

out vec3 t_position;
out vec3 t_velocity;
out float t_deathTime;
out float t_angle;
out float t_angleVelocity;
out vec2 t_size;
out vec2 t_uv00;
out vec2 t_uv10;
out vec2 t_uv01;
out vec2 t_uv11;
out vec3 t_unitX;
out vec3 t_unitY;

void main()
{
const float width = 40;
const float height = 25;
const float xOffset = width * 0.5;
const float yOffset = 3;

vec2 aUV = v_position.xy;
aUV.x = (aUV.x + xOffset) / width;
aUV.y = (aUV.y + yOffset) / height;

vec2 a = texture(accelerationTexture, aUV).xy;

vec3 v = v_velocity;
v.xy += a;

t_position = v_position + v * timeDelta;
t_velocity = v;
t_deathTime = v_deathTime;
t_angle = v_angle + v_angleVelocity * timeDelta;
t_angleVelocity = v_angleVelocity;
t_size = v_size;
t_uv00 = v_uv00;
t_uv10 = v_uv10;
t_uv01 = v_uv01;
t_uv11 = v_uv11;
t_unitX = v_unitX;
t_unitY = v_unitY;
}

";
#endregion

string[] varyings =
#region varyings
    {
        "t_position",
        "t_velocity",
        "t_deathTime",
        "t_angle",
        "t_angleVelocity",
        "t_size",
        "t_uv00",
        "t_uv10",
        "t_uv01",
        "t_uv11",
        "t_unitX",
        "t_unitY",
    };
#endregion

var vs = GL.CreateShader(ShaderType.VertexShader);
#region compile shader
GL.ShaderSource(vs, shaderSource);
GL.CompileShader(vs);

int statusCode;
GL.GetShader(vs, ShaderParameter.CompileStatus, out statusCode);

if (statusCode != 1)
{
    string info;
    GL.GetShaderInfoLog(vs, out info);
    Console.WriteLine("Could not compile shader: " + info);
}
else
{
    Console.WriteLine("Compiled shader.");
}
#endregion

var p = GL.CreateProgram();
#region create program
GL.AttachShader(p, vs);

GL.TransformFeedbackVaryings(p, varyings.Length, varyings,
    TransformFeedbackMode.InterleavedAttribs);

GL.LinkProgram(p);

GL.GetProgram(p, GetProgramParameterName.LinkStatus, out statusCode);

if (statusCode != 1)
{
    string info;
    GL.GetProgramInfoLog(p, out info);
    Console.WriteLine("Could not link program: " + info);
}
else
{
    Console.WriteLine("Linked program.");
}
#endregion

#region GetProgramInterface
int i = 0;
GL.GetProgramInterface(p, ProgramInterface.TransformFeedbackVarying,
    ProgramInterfaceParameter.MaxNameLength, out i);
Console.WriteLine("MaxNameLength: " + i);
Console.WriteLine(GL.GetError());

GL.GetProgramInterface(p, ProgramInterface.TransformFeedbackVarying,
    ProgramInterfaceParameter.ActiveResources, out i);
Console.WriteLine("ActiveResources: " + i);
Console.WriteLine(GL.GetError());
#endregion


Console.WriteLine("all done");
Console.WriteLine(GL.GetError());