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    • By Jens Eckervogt
      Hello guys, 
       
      Please tell me! 
      How do I know? Why does wavefront not show for me?
      I already checked I have non errors yet.
      using OpenTK; using System.Collections.Generic; using System.IO; using System.Text; namespace Tutorial_08.net.sourceskyboxer { public class WaveFrontLoader { private static List<Vector3> inPositions; private static List<Vector2> inTexcoords; private static List<Vector3> inNormals; private static List<float> positions; private static List<float> texcoords; private static List<int> indices; public static RawModel LoadObjModel(string filename, Loader loader) { inPositions = new List<Vector3>(); inTexcoords = new List<Vector2>(); inNormals = new List<Vector3>(); positions = new List<float>(); texcoords = new List<float>(); indices = new List<int>(); int nextIdx = 0; using (var reader = new StreamReader(File.Open("Contents/" + filename + ".obj", FileMode.Open), Encoding.UTF8)) { string line = reader.ReadLine(); int i = reader.Read(); while (true) { string[] currentLine = line.Split(); if (currentLine[0] == "v") { Vector3 pos = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inPositions.Add(pos); if (currentLine[1] == "t") { Vector2 tex = new Vector2(float.Parse(currentLine[1]), float.Parse(currentLine[2])); inTexcoords.Add(tex); } if (currentLine[1] == "n") { Vector3 nom = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inNormals.Add(nom); } } if (currentLine[0] == "f") { Vector3 pos = inPositions[0]; positions.Add(pos.X); positions.Add(pos.Y); positions.Add(pos.Z); Vector2 tc = inTexcoords[0]; texcoords.Add(tc.X); texcoords.Add(tc.Y); indices.Add(nextIdx); ++nextIdx; } reader.Close(); return loader.loadToVAO(positions.ToArray(), texcoords.ToArray(), indices.ToArray()); } } } } } And It have tried other method but it can't show for me.  I am mad now. Because any OpenTK developers won't help me.
      Please help me how do I fix.

      And my download (mega.nz) should it is original but I tried no success...
      - Add blend source and png file here I have tried tried,.....  
       
      PS: Why is our community not active? I wait very longer. Stop to lie me!
      Thanks !
    • By codelyoko373
      I wasn't sure if this would be the right place for a topic like this so sorry if it isn't.
      I'm currently working on a project for Uni using FreeGLUT to make a simple solar system simulation. I've got to the point where I've implemented all the planets and have used a Scene Graph to link them all together. The issue I'm having with now though is basically the planets and moons orbit correctly at their own orbit speeds.
      I'm not really experienced with using matrices for stuff like this so It's likely why I can't figure out how exactly to get it working. This is where I'm applying the transformation matrices, as well as pushing and popping them. This is within the Render function that every planet including the sun and moons will have and run.
      if (tag != "Sun") { glRotatef(orbitAngle, orbitRotation.X, orbitRotation.Y, orbitRotation.Z); } glPushMatrix(); glTranslatef(position.X, position.Y, position.Z); glRotatef(rotationAngle, rotation.X, rotation.Y, rotation.Z); glScalef(scale.X, scale.Y, scale.Z); glDrawElements(GL_TRIANGLES, mesh->indiceCount, GL_UNSIGNED_SHORT, mesh->indices); if (tag != "Sun") { glPopMatrix(); } The "If(tag != "Sun")" parts are my attempts are getting the planets to orbit correctly though it likely isn't the way I'm meant to be doing it. So I was wondering if someone would be able to help me? As I really don't have an idea on what I would do to get it working. Using the if statement is truthfully the closest I've got to it working but there are still weird effects like the planets orbiting faster then they should depending on the number of planets actually be updated/rendered.
    • By Jens Eckervogt
      Hello everyone, 
      I have problem with texture
      using System; using OpenTK; using OpenTK.Input; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL4; using System.Drawing; using System.Reflection; namespace Tutorial_05 { class Game : GameWindow { private static int WIDTH = 1200; private static int HEIGHT = 720; private static KeyboardState keyState; private int vaoID; private int vboID; private int iboID; private Vector3[] vertices = { new Vector3(-0.5f, 0.5f, 0.0f), // V0 new Vector3(-0.5f, -0.5f, 0.0f), // V1 new Vector3(0.5f, -0.5f, 0.0f), // V2 new Vector3(0.5f, 0.5f, 0.0f) // V3 }; private Vector2[] texcoords = { new Vector2(0, 0), new Vector2(0, 1), new Vector2(1, 1), new Vector2(1, 0) }; private int[] indices = { 0, 1, 3, 3, 1, 2 }; private string vertsrc = @"#version 450 core in vec3 position; in vec2 textureCoords; out vec2 pass_textureCoords; void main(void) { gl_Position = vec4(position, 1.0); pass_textureCoords = textureCoords; }"; private string fragsrc = @"#version 450 core in vec2 pass_textureCoords; out vec4 out_color; uniform sampler2D textureSampler; void main(void) { out_color = texture(textureSampler, pass_textureCoords); }"; private int programID; private int vertexShaderID; private int fragmentShaderID; private int textureID; private Bitmap texsrc; public Game() : base(WIDTH, HEIGHT, GraphicsMode.Default, "Tutorial 05 - Texturing", GameWindowFlags.Default, DisplayDevice.Default, 4, 5, GraphicsContextFlags.Default) { } protected override void OnLoad(EventArgs e) { base.OnLoad(e); CursorVisible = true; GL.GenVertexArrays(1, out vaoID); GL.BindVertexArray(vaoID); GL.GenBuffers(1, out vboID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(vertices.Length * Vector3.SizeInBytes), vertices, BufferUsageHint.StaticDraw); GL.GenBuffers(1, out iboID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(int)), indices, BufferUsageHint.StaticDraw); vertexShaderID = GL.CreateShader(ShaderType.VertexShader); GL.ShaderSource(vertexShaderID, vertsrc); GL.CompileShader(vertexShaderID); fragmentShaderID = GL.CreateShader(ShaderType.FragmentShader); GL.ShaderSource(fragmentShaderID, fragsrc); GL.CompileShader(fragmentShaderID); programID = GL.CreateProgram(); GL.AttachShader(programID, vertexShaderID); GL.AttachShader(programID, fragmentShaderID); GL.LinkProgram(programID); // Loading texture from embedded resource texsrc = new Bitmap(Assembly.GetEntryAssembly().GetManifestResourceStream("Tutorial_05.example.png")); textureID = GL.GenTexture(); GL.BindTexture(TextureTarget.Texture2D, textureID); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)All.Linear); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)All.Linear); GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, texsrc.Width, texsrc.Height, 0, PixelFormat.Bgra, PixelType.UnsignedByte, IntPtr.Zero); System.Drawing.Imaging.BitmapData bitmap_data = texsrc.LockBits(new Rectangle(0, 0, texsrc.Width, texsrc.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb); GL.TexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, texsrc.Width, texsrc.Height, PixelFormat.Bgra, PixelType.UnsignedByte, bitmap_data.Scan0); texsrc.UnlockBits(bitmap_data); GL.Enable(EnableCap.Texture2D); GL.BufferData(BufferTarget.TextureBuffer, (IntPtr)(texcoords.Length * Vector2.SizeInBytes), texcoords, BufferUsageHint.StaticDraw); GL.BindAttribLocation(programID, 0, "position"); GL.BindAttribLocation(programID, 1, "textureCoords"); } protected override void OnResize(EventArgs e) { base.OnResize(e); GL.Viewport(0, 0, ClientRectangle.Width, ClientRectangle.Height); } protected override void OnUpdateFrame(FrameEventArgs e) { base.OnUpdateFrame(e); keyState = Keyboard.GetState(); if (keyState.IsKeyDown(Key.Escape)) { Exit(); } } protected override void OnRenderFrame(FrameEventArgs e) { base.OnRenderFrame(e); // Prepare for background GL.Clear(ClearBufferMask.ColorBufferBit); GL.ClearColor(Color4.Red); // Draw traingles GL.EnableVertexAttribArray(0); GL.EnableVertexAttribArray(1); GL.BindVertexArray(vaoID); GL.UseProgram(programID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 0, IntPtr.Zero); GL.ActiveTexture(TextureUnit.Texture0); GL.BindTexture(TextureTarget.Texture3D, textureID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.DrawElements(BeginMode.Triangles, indices.Length, DrawElementsType.UnsignedInt, 0); GL.DisableVertexAttribArray(0); GL.DisableVertexAttribArray(1); SwapBuffers(); } protected override void OnClosed(EventArgs e) { base.OnClosed(e); GL.DeleteVertexArray(vaoID); GL.DeleteBuffer(vboID); } } } I can not remember where do I add GL.Uniform2();
    • By Jens Eckervogt
      Hello everyone
      For @80bserver8 nice job - I have found Google search. How did you port from Javascript WebGL to C# OpenTK.?
      I have been searched Google but it shows f***ing Unity 3D. I really want know how do I understand I want start with OpenTK But I want know where is porting of Javascript and C#?
       
      Thanks!
    • By mike44
      Hi
      I draw in a OpenGL framebuffer. All is fine but it eats FPS (frames per second), hence I wonder if I could execute the framebuffer drawing only every 5-10th loop or so?
      Many thanks
       
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OpenGL Rendering 2D tiles - performance issues

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Hi,
 
I'm currently working on a 2D tile based game. I have to display ~3000 32x32 tiles every frame. However, I'm running into performance issues: the framerate drops to 36 FPS.
My code works the following way: I have one sprite instance per tile, I then store all the tiles for the map in a two dimensional array of Sprite pointers, which point to the tile they represent: std::vector<std::vector<Sprite*>>. To display the map, I iterate through all the pointers, set the right position and draw. Here's a minimalist piece of code which can represent what is globally going on:

/* Creating the map */
Sprite tile;
tile.load("res/sprites/tiles/tile_test32.png");

std::vector<std::vector<Sprite*>> map;

for (int x = 0; x < 64; x++)
{
    map.push_back(std::vector<Sprite*>());
    for (int y = 0; y < 48; y++)
        map[x].push_back(&tile);
}

....

/* Rendering */
for (int x = 0; x < map.size(); x++)
{
    for (int y = 0; y < map[x].size(); y++)
    {
        map[x][y]->setPosition(x * 32, y * 32);
        map[x][y]->draw();
    }
}

I tested this code but with SFML and its sf::Sprite class, it ran at about 240 FPS, instead of a miserable 36 FPS with my sprite class dry.png
 
Here is how my sprites are rendered:

void Sprite::draw()
{
    /* If the sprite is out of the screen, we don't render it */
    if (m_position.x + m_size.x * m_scale.x < 0 || m_position.y + m_size.y * m_scale.y < 0 || m_position.x > SCREEN_WIDTH || m_position.y > SCREEN_HEIGHT)
        return;

    if (m_texture == nullptr) return;

    m_texture->getShader()->use();

    /* Creating and sending the transformation matrices */
    glm::mat4 mvp = Transformable::getTransformationMatrix(SCREEN_WIDTH, SCREEN_HEIGHT);
    glUniformMatrix4fv(glGetUniformLocation(m_texture->getShader()->getProgram(), "mvp"), 1, GL_FALSE, glm::value_ptr(mvp));

    /* Sending the general color */
    glUniform4f(glGetUniformLocation(m_texture->getShader()->getProgram(), "generalColor"), m_color.r, m_color.g, m_color.b, m_color.a);

    m_texture->draw();
}

void Texture::draw()
{
    m_shader->use();

    /* Setting the texture */
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, m_texture);
    glUniform1i(glGetUniformLocation(m_shader->getProgram(), "tex"), 0);

    glEnable(GL_BLEND); /* For RGBA -> transparency */
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    /* Binding the right vao and drawing */
    glBindVertexArray(m_vao);

    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

    /* Unbind texture & VAO */
    glBindVertexArray(0);
    glBindTexture(GL_TEXTURE_2D, 0);
}

The shaders (vertex & fragment) are very minimalist. The vertex data carries a vec2 for position, a vec2 for texCoords and a vec4 for color, per vertex.
The Texture class contains the VAO, the VBO (=vertices), the EBO and the OpenGL texture. The Sprite class is basically just there for the transformations, all the rendering is done in the Texture class.

 

I saw on the internet that binding textures is very costly, I therefore tried to boil down the Texture::draw() function to glBindVertexArray(), glDrawElements() and glBindVertexArray(). It didn't change anything to the performance, even though no texture was applied.

 

Thanks.

Edited by Dexario

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The first thing I notice is that it looks you're issuing a draw call for every single tile. Not to mention (potentially) changing texture and shader state unnecessarily. I'm assuming, except for position, all these tiles are being drawn in essentially the same way. Instead of drawing once for every tile, just bind your shader and texture, submit _all_ the vertices and indices at once and issue a single draw call.

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Try avoiding these boilerplate code (gl_enable, gl_activeTexture, etc) callings for each tile since they won't change between these calls and set them before both of the for blocks too.

 

I would too keep m_texture->getShader()->getProgram() in a variable so I wouldn't call the get methods every time, the cost must be minimum since it is just a get operation, but access to memory is faster than method calling, but most importantly, cleans up the code.

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You can simply compare your code with SFML sources smile.png

 

https://github.com/SFML/SFML/blob/master/src/SFML/Graphics/Sprite.cpp

https://github.com/SFML/SFML/blob/master/src/SFML/Graphics/RenderTarget.cpp

 

As you can see there is almost no difference except:

1. SMFL caches states to prevent redundant state switching

2. It uses deprecated gl*Pointer function and it looks like it doesnt use VBO. If you have alot of different textures and each of them use its own VBO that may be the reason. At least I vaguely recall that I've faced similar issue when using glVertexPointer was cheaper that using alot of small VBO (but that was the case for an old gen iPhone). Sharing single VAO between all the sprites might help your case.

 

Apart from that there are alot of optimization that still can be done. There are some good threads regarding this topic here on gamedev.net. Basically, you should group draw calls by shader, textures, buffers to prevent state switching, draw from front to back, etc.

Edited by Alex Mekhed

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I am indeed drawing all the tiles separately, however, I also did that with SFML and it ran much faster. I looked at the code for rendering sprites in the SFML lib, it seems (to me) they are doing the same. I've broken down and analysed SFML's draw function (https://github.com/SFML/SFML/blob/master/src/SFML/Graphics/RenderTarget.cpp):

 

applyTransform(states.transform); -> applying matrices, transformations

|

applyBlendMode(states.blendMode); -> for RGBA

|

applyTexture(states.texture); -> binding the texture

|- leads to: glCheck(glBindTexture(GL_TEXTURE_2D, texture->m_texture));

|

applyShader(states.shader); -> using the correct shader

|

      const char* data = reinterpret_cast<const char*>(vertices);                              |

      glCheck(glVertexPointer(2, GL_FLOAT, sizeof(Vertex), data + 0));                  |-> binding the vertex data

      glCheck(glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(Vertex), data + 8));  |

      glCheck(glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), data + 12));          |    

|

glCheck(glDrawArrays(mode, 0, vertexCount)); -> drawing

|

applyShader(NULL); -> unbinding the shader

|

applyTexture(NULL); -> unbinding the texture

 

I have to admit I am a bit confused since I can't see any signs of buffers (vao, vbo...), I guess they're using the old OpenGL. The draw() method just takes in an array of vertices and a struct called RenderStates, which contains all the info like shaders, transformations... and follows the steps detailed above.

Edited by Dexario

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I understand that keeping track of what texture is currently loaded to avoid redundancy would increase performance, however, if I change my draw() function to:

void Texture::draw()
{
	glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
} 

The VAO & the texture are already bounded once at the startup and are never unbounded/rebounded after.

With that, I'm running at .... 39 FPS mellow.png , which represents an increase of 3 FPS.

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GL_TRIANGLE_STRIP instead of GL_TRIANGLES?

 

Another bottleneck might be here: Transformable::getTransformationMatrix(SCREEN_WIDTH, SCREEN_HEIGHT);

SFML caches transform matrices

Edited by Alex Mekhed

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You should set your 2d loop variables in your rendering section to proper values and avoid pointless iterations. Not sure how mush time it will gain you but it will some for sure.

 

Instead of :

/* Rendering */
for (int x = 0; x < map.size(); x++)
{
    for (int y = 0; y < map[x].size(); y++)
    {
        map[x][y]->setPosition(x * 32, y * 32);
        map[x][y]->draw();
    }
}

Try something like:

/* Rendering */
for (int x = pos.x - somewidth; x < pos.x + somewidth; x++)
{
    for (int y = pos.y - someheight; y < pos.y + someheight; y++)
    {
        map[x][y]->setPosition(x * 32, y * 32);
        map[x][y]->draw();
    }
}

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