EDIT: Problem partially resolved, see post #8.
Hello,
I'm beginning OpenGL 4.2 in C# using the OpenTK binding (I'm aware that OpenTK binds only up to 3.2, so they have deprecated stuff available so I'm not using those functions, ya know... forward compatibility
). Anyways, so I have got this basic pass-through vertex shader: (also embedded in program below)[source lang="c"]
#version 410
#pragma debug(on)
uniform mat4 projection;
uniform mat4 view;
vec3 inVertexPos;
void main()
{
gl_Position = vec4(inVertexPos, 1.0) * projection * view;
}
[/source]
The problem I am having is marked on line 48 (generic vertex attribute location equals -1) below.
I can't seem to understand the reason for the error (as OpenGL does not really throw an error...), [s]the OpenGL reference suggets it has to do with maximum generic vertex attribs; ....but it clearly doesn't.[/s]
Anyone can shed some light on the problem? I'll be most thankful.
(The entire code-file is attached as a file to the post as well)
The main program (this is a class constructor, after this function returns the main loop runs calling the render function below):
[source lang="csharp"]
Matrix4 Projection;
Matrix4 View;
int[] ShaderIDs;
int[] ProgramIDs;
uint[] VAOs;
uint[] VBOs;[font="arial, verdana, tahoma, sans-serif"]
ushort[] Indices; // Cube indices
Vector3[] Vertices; // Cube vertices
public GameCtor()
{
[font="arial, verdana, tahoma, sans-serif"] [/font]// Our uniform matrices
[font="arial, verdana, tahoma, sans-serif"] [/font]Projection = Matrix4.CreatePerspectiveOffCenter(-Width / 2, Width / 2, -Height / 2, Height / 2, 0.01f, 500); // Perspective with 0,0 in the center and same as window width and height
[font="arial, verdana, tahoma, sans-serif"] [/font]View = Matrix4.LookAt(0, 0, -100, 0, 0, 0, 0, 1, 0); // camera at (z = -100) looking at 0,0,0
[/font][font="arial, verdana, tahoma, sans-serif"]
VAOs = new uint[1];
VBOs = new uint[2];
ShaderIDs = new int[2]; // Reserve space for 2 shaders, here we use one vertex shader
ProgramIDs = new int[1]; // Our shader program[/font]
[font="arial, verdana, tahoma, sans-serif"]
GL.GenVertexArrays(VAOs.Length, VAOs);[/font]
GL.GenBuffers(VBOs.Length, VBOs);
InitVAOsVBOs();
InitVertexShader(); // Initialize our vertex shader
// Create a program and attach our first shader
ProgramIDs[0] = GL.CreateProgram();
GL.AttachShader(ProgramIDs[0], ShaderIDs[0]);
// Link and print result log
GL.LinkProgram(ProgramIDs[0]);
Console.WriteLine(GL.GetProgramInfoLog(ProgramIDs[0]));
// Start using our shader program
// Required before setting Uniforms,
// otherwise I get an error: InvalidValue
GL.UseProgram(ProgramIDs[0]);
// Set uniform projection and view matrices
int uProjIndex = GL.GetUniformLocation(ProgramIDs[0], "projection");
int uViewIndex = GL.GetUniformLocation(ProgramIDs[0], "view");
GL.UniformMatrix4(uProjIndex, true, ref Projection);
GL.UniformMatrix4(uViewIndex, true, ref View);
// Vertex Position attribute: vec3 inVertexPos;
int inVertexPosIndex = GL.GetAttribLocation(ProgramIDs[0], "inVertexPos"); // returns -1
GL.BindVertexArray(VAOs[0]);
GL.VertexAttribPointer(inVertexPosIndex, 3, VertexAttribPointerType.Float, false, 0, IntPtr.Zero);
GL.EnableVertexAttribArray(inVertexPosIndex);}
[/source]
Buffer initialization:
[source lang="csharp"]
private void InitVAOsVBOs()
{
Vertices = new Vector3[8] {
new Vector3(-80, 80, -80), //0 Top, Left, Front
new Vector3(-80, 80, 80), //1 Top, Left, Back
new Vector3(-80, -80, -80), //2 Top, Right, Front
new Vector3(-80, -80, 80), //3 Top, Right, Back
new Vector3( 80, 80, 80), //4 Bottom, Left, Front
new Vector3( 80, 80, -80), //5 Bottom, Left, Back
new Vector3( 80, -80, -80), //6 Bottom, Right, Front
new Vector3( 80, -80, 80) //7 Bottom, Right, Back
};
GL.BindBuffer(BufferTarget.ArrayBuffer, VBOs[0]);
GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(Vertices.Length * Vector3.SizeInBytes), Vertices, BufferUsageHint.StaticDraw);
GL.BindVertexArray(VAOs[0]);
Indices = new ushort[24] {
0, 1, 3, 2, // Top face
0, 1, 5, 4, // Left face
1, 3, 7, 5, // Back face
2, 3, 7, 6, // Right face
4, 5, 7, 6, // Bottom face
0, 2, 6, 4 // Front face
};
GL.BindBuffer(BufferTarget.ElementArrayBuffer, VBOs[0]);
GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(Indices.Length * sizeof(ushort)), Indices, BufferUsageHint.StaticDraw);
}[/source]
Vertex Shader initialization:
[source lang="csharp"]
private void InitVertexShader()
{
string VertexShaderSource = // Yes, this is inline shader source
@"#version 410
#pragma debug(on)
uniform mat4 projection;
uniform mat4 view;
vec3 inVertexPos;
void main()
{
gl_Position = vec4(inVertexPos, 1.0) * projection * view;
}";
// Create our vertex shader, upload our source, and compile
ShaderIDs[0] = GL.CreateShader(ShaderType.VertexShader);
GL.ShaderSource(ShaderIDs[0], VertexShaderSource);
GL.CompileShader(ShaderIDs[0]);
Console.WriteLine(GL.GetShaderInfoLog(ShaderIDs[0])); // check the log to make sure it succeeds
}
[/source]
Render code:
[source lang="csharp"]
protected override void OnRenderFrame(FrameEventArgs e)
{
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
// Draw using the indices buffer
GL.DrawElements(BeginMode.Quads, Indices.Length, DrawElementsType.UnsignedShort, 0);
this.SwapBuffers();
}
[/source]
