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SharpGL 2D Texturing issue

I am trying to texture triangle with runtime generated texture using SharpGL wrapper.
I can't figure out why triangle remains not textured.
gl.Error() put in draw loop returns 0 which means GL_NO_ERROR.
private void openGLControl_OpenGLDraw(object sender, OpenGLEventArgs args)
{
OpenGL gl = openGLControl.OpenGL;
gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT | OpenGL.GL_DEPTH_BUFFER_BIT );
gl.LoadIdentity();
gl.Color(1.0f,1.0f,1.0f,1.0f);
gl.Begin(OpenGL.GL_TRIANGLES);
gl.TexCoord(0, 1.0f);
gl.Vertex(0.0f, 0.0f);
gl.TexCoord(1.0f, 0f);
gl.Vertex(1.0f, 0f);
gl.TexCoord(1.0f, 1.0f);
gl.Vertex(1.0f, 1.0f);
gl.End();
}
private void openGLControl_OpenGLInitialized(object sender, OpenGLEventArgs args)
{
Random rnd = new Random();
OpenGL gl = openGLControl.OpenGL;
gl.ClearColor(0, 0, 0, 0);
gl.Enable(OpenGL.GL_TEXTURE_2D);
byte[] colors = new byte[256 * 256 * 4];
for (int i = 0; i < 256 * 256 * 4; i++)
{
colors[i] = (byte)rnd.Next(256);
}
uint[] textureID = new uint[1];
gl.GenTextures(1, textureID);
gl.TexImage2D(OpenGL.GL_TEXTURE_2D, 0, (int)OpenGL.GL_RGBA, 256, 256, 0, OpenGL.GL_RGBA, OpenGL.GL_BYTE, colors);
gl.BindTexture(OpenGL.GL_TEXTURE_2D, textureID[0]);
}

You have to call gl.BindTexture before calling gl.TexImage2D.
The reason for this is in the first argument of both functions. OpenGL has a state machine that keeps track of what is bound. When you call gl.TexImage2D, you are telling GL to upload the pixels to the texture currently bound to OpenGL.GL_TEXTURE_2D. gl.BindTexture binds the texture you generated to OpenGL.GL_TEXTURE_2D.

The reason why texture wasn't visible was lacking setting:
uint[] array = new uint[] { OpenGL.GL_NEAREST };
gl.TexParameterI(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MIN_FILTER, array);
gl.TexParameterI(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MAG_FILTER, array);
By default SharpGL is using MipMap which weren't generated.

OpenTK Ortho Camera causes objects not to show

I'm trying to draw objects on my screen in 2D and translate them on a pixel by pixel bases.
Here is my render code, and for some reason it's not showing my objects anymore. It showed them before I added the Ortho Camera. What's going on?
Thanks!
game.RenderFrame += (sender, e) =>
{
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadIdentity();
GL.Ortho(0, 800, 600, 0, -1, 1);
GL.MatrixMode(MatrixMode.Modelview);
GL.LoadIdentity();
// GL.ActiveTexture(TextureUnit.Texture0);
int textID = loadTexture(Rock);
GL.BindTexture(TextureTarget.Texture2D, textID);
drawObject(100, 20, 0.15f, 0.15f);
drawObject(100, 60, 0.15f, 0.15f);
drawObject(100, 100,0.15f, 0.15f);
game.SwapBuffers();
};
drawObject(PosX, PosY, ScaleX, ScaleY);
and within my drawObject method I am using
`GL.Translate(PosX, PosY, 0);`

OpenGL texture rendering - only upper left pixel is displayed

I working with C# and OpenTK.
Currently I only want to map a texture on a triangle.
It seems to be working but on nearest texture filter, the whole triangle is only colored with the upper left pixel color of the bmp image and if I set the texture filter to linear the triangle shows still only one color, but it seems whether it is now mixed with the other pixels.
Can someone find the error in the code ?
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
GL.Enable(EnableCap.Texture2D);
GL.ClearColor(0.5F, 0.5F, 0.5F, 1.0F);
int vertexShaderHandle = GL.CreateShader(ShaderType.VertexShader);
int fragmentShaderHandle = GL.CreateShader(ShaderType.FragmentShader);
string vertexShaderSource = #"#version 400
layout(location = 0) in vec3 position;
layout(location = 1) in vec2 uv;
out vec2 texture_uv;
void main()
{
gl_Position = vec4(inPosition.xyz, 1);
texture_uv = uv;
}";
string fragmentShaderSource = #"#version 400
in vec2 texture_uv;
out vec3 outColor;
uniform sampler2D uniSampler;
void main()
{
outColor = texture( uniSampler, texture_uv ).rgb;
}";
GL.ShaderSource(vertexShaderHandle, vertexShaderSource);
GL.ShaderSource(fragmentShaderHandle, fragmentShaderSource);
GL.CompileShader(vertexShaderHandle);
GL.CompileShader(fragmentShaderHandle);
prgHandle = GL.CreateProgram();
GL.AttachShader(prgHandle, vertexShaderHandle);
GL.AttachShader(prgHandle, fragmentShaderHandle);
GL.LinkProgram(prgHandle);
GL.DetachShader(prgHandle, vertexShaderHandle);
GL.DetachShader(prgHandle, fragmentShaderHandle);
GL.DeleteShader(vertexShaderHandle);
GL.DeleteShader(fragmentShaderHandle);
uniSamplerLoc = GL.GetUniformLocation(prgHandle, "uniSampler");
texHandle = GL.GenTexture();
GL.BindTexture(TextureTarget.Texture2D, texHandle);
Bitmap bmp = new Bitmap("C:/Users/Michael/Desktop/Test.bmp");
BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, bmpData.Width, bmpData.Height, 0,
OpenTK.Graphics.OpenGL4.PixelFormat.Bgra, PixelType.UnsignedByte, bmpData.Scan0);
bmp.UnlockBits(bmpData);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Nearest);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Nearest);
vaoHandle = GL.GenVertexArray();
GL.BindVertexArray(vaoHandle);
vboHandle = GL.GenBuffer();
GL.BindBuffer(BufferTarget.ArrayBuffer, vboHandle);
float[] bufferData = { 0.5F, 1, 0, 1, 1,
0, 0, 0, 0, 0,
1, 0, 0, 1, 0 };
GL.BufferData<float>(BufferTarget.ArrayBuffer, (IntPtr) (15 * sizeof(float)), bufferData, BufferUsageHint.StaticDraw);
GL.EnableVertexAttribArray(0);
GL.EnableVertexAttribArray(1);
GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 5 * sizeof(float), 0);
GL.VertexAttribPointer(1, 2, VertexAttribPointerType.Float, false, 5 * sizeof(float), 3 * sizeof(float));
}
protected override void OnUnload(EventArgs e)
{
base.OnUnload(e);
GL.DeleteTexture(texHandle);
GL.DeleteProgram(prgHandle);
GL.DeleteBuffer(vboHandle);
GL.DeleteVertexArray(vaoHandle);
}
protected override void OnRenderFrame(FrameEventArgs e)
{
base.OnRenderFrame(e);
GL.Clear(ClearBufferMask.ColorBufferBit);
GL.UseProgram(prgHandle);
GL.Uniform1(uniSamplerLoc, texHandle);
GL.BindVertexArray(vaoHandle);
GL.DrawArrays(PrimitiveType.Triangles, 0, 3);
SwapBuffers();
}
EDIT:
I tried this:
protected override void OnRenderFrame(FrameEventArgs e)
{
base.OnRenderFrame(e);
GL.Clear(ClearBufferMask.ColorBufferBit);
GL.UseProgram(prgHandle);
GL.BindVertexArray(vaoHandle);
GL.ActiveTexture(TextureUnit.Texture3);
GL.BindTexture(TextureTarget.Texture2D, texHandle);
GL.Uniform1(uniSamplerLoc, 3);
GL.DrawArrays(PrimitiveType.Triangles, 0, 3);
SwapBuffers();
}
But nothing changed :(

The value of a sampler uniform variable needs to be the texture unit it should sample from. In your code, it is set to the texture name (aka texture id, aka texture handle) instead:
GL.Uniform1(uniSamplerLoc, texHandle);
The texture unit can be set with ActiveTexture(). When glBindTexture() is called, the value of the currently active texture unit determines which unit the texture is bound to. The default for the active texture unit is 0. So if you never called ActiveTexture(), the uniform should be set as:
GL.Uniform1(uniSamplerLoc, 0);
Just as a heads-up, another related source of errors is that the value of the uniform is a 0-based index of the texture unit, while the glActiveTexture() call takes an enum starting with GL_TEXTURE0. For example with the C bindings (not sure how exactly this looks with C# and OpenTK, but it should be similar enough), this would bind a texture to texture unit 3, and set a uniform sampler variable to use it:
glActiveTexture(GL_TEXTURE3);
glBindTexture(GL_TEXTURE_2D, texId);
glUniform1i(texUniformLoc, 3);
Note how GL_TEXTURE3 is used in the argument for glActiveTexture(), but a plain 3 in glUniform1i().

OpenTK C# Perspective Lighting looks glitchy

My goal is to make lighting in perspective view smooth. I'm using the same light settings for both perspective and orthographic. The images below show that the orthographic lighting looks great. The perspective lighting looks glitchy and flickers when I rotate it. What am I missing that would make the perspective view lighting look okay?
Processor: AMD FX 6100 6-core 3.31GHz
Graphics: AMD Radeon HD 6800
Note: I referenced from an OpenGL example. I was playing with the different light settings to find out how they work. The code I pasted at the end of this post is the code that created the images.
Perspective: http://i.stack.imgur.com/pSXul.png
Orthographic: http://i.stack.imgur.com/Q7Yr2.png
Here is the relevant code within my paint method.
private void glControl1_Paint(object sender, PaintEventArgs e)
{
if (!glLoaded)
return;
GL.Enable(EnableCap.DepthTest);
//GL.Enable(EnableCap.Blend);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
//SET PERSPECTIVE OR ORTHOGRAPHIC VIEW
if (chkPerspective.Checked)
{
double aspect = glControl1.Width / (double)glControl1.Height;
Matrix4 perspective = Matrix4.CreatePerspectiveFieldOfView(MathHelper.PiOver4, (float)aspect, 0.0001f, 5000.0f);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadIdentity();
GL.LoadMatrix(ref perspective);
Matrix4 lookat = Matrix4.LookAt(eyeOffset.X, eyeOffset.Y, eyeOffset.Z, 0, 0, 0, 0, 1, 0);
GL.MatrixMode(MatrixMode.Modelview);
GL.LoadMatrix(ref lookat);
//GL.Translate(-boxOffset);
}
else
{
setupViewPort(); //Orthographic settings
GL.MatrixMode(MatrixMode.Modelview);
GL.LoadIdentity();
}
GL.Rotate(angleY, 1.0f, 0, 0);
GL.Rotate(angleX, 0, 1.0f, 0);
//LIGHTING
if (chkLighting.Checked)
{
float[] mat_specular = { 1.0f, 1.0f, 1.0f, 1.0f };
float[] mat_shininess = { 50.0f };
float[] light_position = { 1000.0f, 1000.0f, 1000.0f, 100.0f };
float[] light_ambient = { 0.5f, 0.5f, 0.5f, 1.0f };
GL.ClearColor(0.0f, 0.0f, 0.0f, 1.0f);
//GL.ShadeModel(ShadingModel.Smooth);
//GL.Material(MaterialFace.Front, MaterialParameter.Specular, mat_specular);
//GL.Material(MaterialFace.Front, MaterialParameter.Shininess, mat_shininess);
GL.Light(LightName.Light0, LightParameter.Position, light_position);
//GL.Light(LightName.Light0, LightParameter.Ambient, light_ambient);
//GL.Light(LightName.Light0, LightParameter.Diffuse, mat_specular);
GL.Enable(EnableCap.Lighting);
GL.Enable(EnableCap.Light0);
GL.Enable(EnableCap.ColorMaterial);
//GL.Enable(EnableCap.CullFace);
}
else
{
GL.Disable(EnableCap.Lighting);
GL.Disable(EnableCap.Light0);
}
foreach (Cube cube in cubes)
{
cube.drawCube(selectionCubeRadius);
}
glControl1.SwapBuffers();
}
Here is my orthographic viewport code in case it matters.
private void setupViewPort()
{
if (chkPerspective.Checked)
return;
int w = glControl1.Width;
int h = glControl1.Height;
GL.MatrixMode(MatrixMode.Projection);
GL.LoadIdentity();
GL.Ortho(-w, w, -h, h, -5000, 5000); // Bottom-left corner pixel has coordinate (0, 0)
GL.Viewport(0, 0, w, h); // Use all of the glControl paintingarea
}

Based solely on the images, it looks like depth test is being disabled or some normals are flipped or non-normalized.
What does drawCube do exactly?

I found a solution that will work for now. In perspective view, I reduced the size of the cubes from 200.0 to 5.0. Then I moved the camera closer so they appear the same size. Some also said that I should decrease the far Z-plane when I create my perspective field of view.
Reducing the size of my models worked, but I also decreased the distance of the far z-plane for convention purposes. I'll also likely create an algorithm that determines what z-plane distance to use based on my current model size and angle.
User 'dflemstr' asked about my GL.Normal3f calls. The answer is that I have none. What do they do, and are they necessary?

Can't Draw SharpGL(openGL wrapper) object in EMGU CV

I've been working with emgu cv(opencv wrapper to capture images from a webcam and using its functions to proccess this images.
I also detect the hand and track the hand movement...
Now, I need to draw a kind of earth or just an object according to the hand position, for which sharpGL is perfect for perspective transformation and so on. My problem is that I can't achieve that.
I don't know how to say to sharpGL "you guy, draw that object within this hand tracking window"
Is it impossible what I want to do? I am desperate... any help would be great. Thanks in advance
see this video if you're still confused about what I meant (http://www.youtube.com/watch?v=ccL4t36sVvg)
so far, I've just translated this code http://blog.damiles.com/2008/10/opencv-opengl/ into C#
and here's code snippet
private void openGLControl_OpenGLInitialized(object sender, EventArgs e)
{
// TODO: Initialise OpenGL here.
// The texture identifier.
uint[] textures = new uint[1];
// Get the OpenGL object.
OpenGL gl = openGLControl1.OpenGL;
//texture.Create(gl);
// Get one texture id, and stick it into the textures array.
gl.GenTextures(1, textures);
// Bind the texture.
gl.BindTexture(OpenGL.GL_TEXTURE_2D, textures[0]);
// A bit of extra initialisation here, we have to enable textures.
gl.Enable(OpenGL.GL_TEXTURE_2D);
// Specify linear filtering.
gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MIN_FILTER, OpenGL.GL_NEAREST);
gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MAG_FILTER, OpenGL.GL_NEAREST);
gl.PixelStore(OpenGL.GL_UNPACK_ALIGNMENT, 1);
// Set the clear color.
gl.ClearColor(1.0f, 1.0f, 1.0f, 1.0f);
}
private void openGLControl_Resized(object sender, EventArgs e)
{
// TODO: Set the projection matrix here.
// Get the OpenGL object.
OpenGL gl = openGLControl1.OpenGL;
// Set the projection matrix.
gl.MatrixMode(OpenGL.GL_PROJECTION);
// Load the identity.
gl.LoadIdentity();
// Create a perspective transformation.
gl.Perspective(60.0f, (double)Width / (double)Height, 0.01, 100.0);
// Use the 'look at' helper function to position and aim the camera.
gl.LookAt(-5, 5, -5, 0, 0, 0, 0, 1, 0);
// Set the modelview matrix.
gl.MatrixMode(OpenGL.GL_MODELVIEW);
}
and finally draw an 3D object
private void openGLControl_OpenGLDraw(object sender, PaintEventArgs e)
{
// Get the OpenGL object.
OpenGL gl = openGLControl1.OpenGL;
if (capture == null)
{
this.start_capture();
}
if (capture != null)
{
Image<Bgr, Byte> ImageFrame = capture.QueryFrame();
//I'm trying to use some algorithm using the code from sample (sharpGLTextureExample)
//first, I make an Bitmap object that I take from queryframe(convert it to bitmap first)
Bitmap image = new Bitmap(ImageFrame.ToBitmap());
// Clear the color and depth buffer.
gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT | OpenGL.GL_DEPTH_BUFFER_BIT);
//ImageFrame.Draw(new Rectangle(2, 2, 2, 2), new Bgr(Color.Aqua), 2);
// Load the identity matrix.
gl.LoadIdentity();
//then, Lock the image bits (so that we can pass them to OGL).
BitmapData bitmapData = image.LockBits(new Rectangle(0, 0, image.Width, image.Height),
ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
gl.BindTexture(OpenGL.GL_TEXTURE_2D, textures[0]);
//gl.TexImage2D(OpenGL.GL_TEXTURE_2D, 0, (int)OpenGL.GL_RGBA, ImageFrame.Width, ImageFrame.Height, 0, OpenGL.GL_RGBA, OpenGL.GL_UNSIGNED_BYTE, ImageFrame);
gl.TexImage2D(OpenGL.GL_TEXTURE_2D, 0, (int)OpenGL.GL_RGBA, ImageFrame.Width, ImageFrame.Height, 0, OpenGL.GL_RGBA, OpenGL.GL_UNSIGNED_BYTE, bitmapData.Scan0);
//gl.Begin(OpenGL.GL_QUADS);
//gl.TexCoord(0, 0); gl.Vertex(-1, -1, 0);
//gl.TexCoord(1, 0); gl.Vertex(1, -1, 0);
//gl.TexCoord(1, 5); gl.Vertex(1, 1, 0);
//gl.TexCoord(0, 1); gl.Vertex(-1, 1, 0);
//gl.End();
//gl.Flush();
//texture.Bind(gl);
//
//CamImageBox.Image = ImageFrame;
}
}
but the output always return an white, no texture on it...
I've also consindering to use Texture class, but it's no use..because there's no method which the input parameter is the frame...

From your code and help from http://basic4gl.wikispaces.com/2D+Drawing+in+OpenGL, I got SharpGL displaying a video from EmguCV
public partial class FormSharpGLTexturesSample : Form
{
Capture capture;
public FormSharpGLTexturesSample()
{
InitializeComponent();
// Get the OpenGL object, for quick access.
SharpGL.OpenGL gl = this.openGLControl1.OpenGL;
// A bit of extra initialisation here, we have to enable textures.
gl.Enable(OpenGL.GL_TEXTURE_2D);
gl.Disable(OpenGL.GL_DEPTH_TEST);
// Create our texture object from a file. This creates the texture for OpenGL.
capture = new Capture(#"Video file here");
}
private void openGLControl1_OpenGLDraw(object sender, RenderEventArgs e)
{
// Get the OpenGL object, for quick access.
SharpGL.OpenGL gl = this.openGLControl1.OpenGL;
int Width = openGLControl1.Width;
int Height = openGLControl1.Height;
gl.Clear(OpenGL.GL_COLOR_BUFFER_BIT);
gl.LoadIdentity();
var frame = capture.QueryFrame();
texture.Destroy(gl);
texture.Create(gl, frame.Bitmap);
// Bind the texture.
texture.Bind(gl);
gl.Begin(OpenGL.GL_QUADS);
gl.TexCoord(0.0f, 0.0f); gl.Vertex(0, 0, 0);
gl.TexCoord(1.0f, 0.0f); gl.Vertex(Width, 0, 0);
gl.TexCoord(1.0f, 1.0f); gl.Vertex(Width, Height, 0);
gl.TexCoord(0.0f, 1.0f); gl.Vertex(0, Height, 0);
gl.End();
gl.Flush();
}
// The texture identifier.
Texture texture = new Texture();
private void openGLControl1_Resized(object sender, EventArgs e)
{
SharpGL.OpenGL gl = this.openGLControl1.OpenGL;
// Create an orthographic projection.
gl.MatrixMode(MatrixMode.Projection);
gl.LoadIdentity();
// NOTE: Basically no matter what I do, the only points I see are those at
// the "near" surface (with z = -zNear)--in this case, I only see green points
gl.Ortho(0, openGLControl1.Width, openGLControl1.Height, 0, 0, 1);
// Back to the modelview.
gl.MatrixMode(MatrixMode.Modelview);
}
}
I hope it helps.
After some experiments, I could use TexImage2D but only with images having a width and height be a power of two
Instead of:
var frame = capture.QueryFrame();
texture.Destroy(gl);
texture.Create(gl, frame.Bitmap);
It can be replaced by the following block to update the data of the picture. I would like to know how to remove the need to call Resize.
var frame = capture.QueryFrame();
frame = frame.Resize(256, 256, Emgu.CV.CvEnum.INTER.CV_INTER_NN);
Bitmap Bitmap = frame.Bitmap;
BitmapData bitmapData = Bitmap.LockBits(new Rectangle(0, 0, Bitmap.Width, Bitmap.Height),
ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
gl.BindTexture(OpenGL.GL_TEXTURE_2D, textures[0]);
gl.TexImage2D(OpenGL.GL_TEXTURE_2D, 0, OpenGL.GL_RGBA, Bitmap.Width, Bitmap.Height, 0, OpenGL.GL_BGR, OpenGL.GL_UNSIGNED_BYTE, bitmapData.Scan0);
gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MIN_FILTER, OpenGL.GL_LINEAR); // Required for TexImage2D
gl.TexParameter(OpenGL.GL_TEXTURE_2D, OpenGL.GL_TEXTURE_MAG_FILTER, OpenGL.GL_LINEAR); // Required for TexImage2D