Sign in to follow this  
8Observer8

OpenGL gl_PointSize doesn't work

Recommended Posts

8Observer8    160

Hello

I want to draw a point with custom size in C# OpenGL3.3 OpenTK like this: https://jsfiddle.net/8Observer8/cc72u1u5/

But I see the point with size 1 pixel

I attached the project. Everyone can run it in VS 2012 - VS 2015

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using OpenTK;
using OpenTK.Graphics.OpenGL;
using Utils;

namespace HelloPoint1
{
    class MainWindow : GameWindow
    {
        string VSHADER_SOURCE = null;
        string FSHADER_SOURCE = null;

        bool canDraw = false;

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            // Load shaders from files
            ShaderLoader.LoadShader("./Shaders/vShader.glsl", out VSHADER_SOURCE);
            ShaderLoader.LoadShader("./Shaders/fShader.glsl", out FSHADER_SOURCE);
            if (VSHADER_SOURCE == null || FSHADER_SOURCE == null)
            {
                Console.WriteLine("Failed to load shaders from files");
                return;
            }

            // Specify the color for clearing
            GL.ClearColor(Color.Black);

            GL.Enable(EnableCap.ProgramPointSize);

            canDraw = true;
        }

        protected override void OnRenderFrame(FrameEventArgs e)
        {
            base.OnRenderFrame(e);

            if (!canDraw) return;

            GL.Clear(ClearBufferMask.ColorBufferBit);

            // Draw a point
            GL.DrawArrays(PrimitiveType.Points, 0, 1);

            GL.Flush();

            SwapBuffers();
        }
    }
}

Edited by 8Observer8

Share this post


Link to post
Share on other sites
slicer4ever    6760

can you provide the source to base.OnLoad(); and base.OnRenderFrame(e);  otherwise i don't even see you setting up vertices, yet alone setting their sizes.

Edited by slicer4ever

Share this post


Link to post
Share on other sites
8Observer8    160
Now it works!
 
PointWithCustomSizeAndColour_512x512.png
 
I forgot to initialise the shaders.
 
 
vShader.glsl
#version 330
 
void main()
{
    gl_Position = vec4(0.8, 0.0, 0.0, 1.0);
    gl_PointSize = 10.0;
}
 
fShader.glsl
#version 330
 
out vec4 fragColor;
 
void main()
{
    fragColor = vec4(1.0, 0.0, 0.0, 1.0);
}
 
Program.cs
namespace PointWithCustomSizeAndColour
{
    class Program
    {
        static void Main(string[] args)
        {
            using (MainWindow mainWindow = new MainWindow())
            {
                mainWindow.Run(30);
            }
        }
    }
}
 
MainWindow.cs
using System;
using System.Drawing;
using OpenTK;
using OpenTK.Graphics.OpenGL;
using System.IO;

namespace PointWithCustomSizeAndColour
{
    class MainWindow : GameWindow
    {
        string vShaderSource = null;
        string fShaderSource = null;

        bool canDraw = false;

        string infoFileName = "info.txt";

        int program;

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            Title = "Point With Custom Size And Colour";
            Width = 512;
            Height = 512;

            // Load shaders from files
            ShaderLoader.LoadShader(infoFileName, "./Shaders/vShader.glsl", out vShaderSource);
            ShaderLoader.LoadShader(infoFileName, "./Shaders/fShader.glsl", out fShaderSource);
            if (vShaderSource == null || fShaderSource == null)
            {
                File.AppendAllText(infoFileName, "Failed to load shaders from files" + Environment.NewLine);
                return;
            }

            // Initialize shaders
            if (!ShaderLoader.InitShaders(vShaderSource, fShaderSource, out program))
            {
                File.AppendAllText(infoFileName, "Failed to initialize the shaders" + Environment.NewLine);
                return;
            }

            // Specify the color for clearing
            GL.ClearColor(Color.Black);

            GL.Enable(EnableCap.ProgramPointSize);

            canDraw = true;
        }

        protected override void OnRenderFrame(FrameEventArgs e)
        {
            base.OnRenderFrame(e);
            GL.Viewport(0, 0, Width, Height);

            if (!canDraw) return;

            GL.Clear(ClearBufferMask.ColorBufferBit);

            // Draw a point
            GL.DrawArrays(PrimitiveType.Points, 0, 1);

            GL.Flush();
            SwapBuffers();
        }
    }
}

 
ShaderLoader.cs
using System.IO;
using OpenTK.Graphics.OpenGL;
using System;
 
namespace PointWithCustomSizeAndColour
{
    class ShaderLoader
    {
        private static string infoFileName = null;
 
        ///<summary>
        ///Create a program object and make current
        ///</summary>
       ///<param name="vShader">a vertex shader program</param>
        ///<param name="fShader">a fragment shader program</param>
        ///<param name="program">created program</param>
        ///<returns>
        ///return true, if the program object was created and successfully made current
        ///</returns>
        public static bool InitShaders(string vShader, string fShader, out int program)
        {
            program = CreateProgram(vShader, fShader);
            if (program == 0)
            {
                File.AppendAllText(infoFileName, "Failed to create program" + Environment.NewLine);
                return false;
            }
 
            GL.UseProgram(program);
 
            return true;
        }
 
        ///<summary>
        ///Load a shader from a file
        ///</summary>
        ///<param name="infoFileName">a file name for errors</param>
        ///<param name="fileName">a file name to a shader</param>
        ///<param name="shaderSource">a shader source string</param>
        public static void LoadShader(string infoFileName, string fileName, out string shaderSource)
        {
            ShaderLoader.infoFileName = infoFileName;
 
            if (File.Exists(infoFileName))
            {
                // Clear File
                File.WriteAllText(infoFileName, "");
            }
 
            shaderSource = null;
 
            using (StreamReader sr = new StreamReader(fileName))
            {
                shaderSource = sr.ReadToEnd();
            }
        }
 
        private static int CreateProgram(string vShader, string fShader)
        {
            // Create shader object
            int vertexShader = LoadShader(ShaderType.VertexShader, vShader);
            int fragmentShader = LoadShader(ShaderType.FragmentShader, fShader);
            if (vertexShader == 0 || fragmentShader == 0)
            {
                return 0;
            }
 
            // Create a program object
            int program = GL.CreateProgram();
            if (program == 0)
            {
                return 0;
            }
 
            // Attach the shader objects
            GL.AttachShader(program, vertexShader);
            GL.AttachShader(program, fragmentShader);
 
            // Link the program object
            GL.LinkProgram(program);
 
            // Check the result of linking
            int status;
            GL.GetProgram(program, GetProgramParameterName.LinkStatus, out status);
            if (status == 0)
            {
                string errorString = string.Format("Failed to link program: {0}" + Environment.NewLine, GL.GetProgramInfoLog(program));
                File.AppendAllText(infoFileName, errorString);
                GL.DeleteProgram(program);
                GL.DeleteShader(vertexShader);
                GL.DeleteShader(fragmentShader);
                return 0;
            }
 
            return program;
        }
 
        private static int LoadShader(ShaderType shaderType, string shaderSource)
        {
            // Create shader object
            int shader = GL.CreateShader(shaderType);
            if (shader == 0)
            {
                File.AppendAllText(infoFileName, "Unable to create shader" + Environment.NewLine);
                return 0;
            }
 
            // Set the shader program
            GL.ShaderSource(shader, shaderSource);
 
            // Compile the shader
            GL.CompileShader(shader);
 
            // Check the result of compilation
            int status;
            GL.GetShader(shader, ShaderParameter.CompileStatus, out status);
            if (status == 0)
            {
                string errorString = string.Format("Failed to compile {0} shader: {1}" + Environment.NewLine, shaderType.ToString(), GL.GetShaderInfoLog(shader));
                File.AppendAllText(infoFileName, errorString);
                GL.DeleteShader(shader);
                return 0;
            }
 
            return shader;
        }
    }
}
Edited by 8Observer8

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Similar Content

    • By Kjell Andersson
      I'm trying to get some legacy OpenGL code to run with a shader pipeline,
      The legacy code uses glVertexPointer(), glColorPointer(), glNormalPointer() and glTexCoordPointer() to supply the vertex information.
      I know that it should be using setVertexAttribPointer() etc to clearly define the layout but that is not an option right now since the legacy code can't be modified to that extent.
      I've got a version 330 vertex shader to somewhat work:
      #version 330 uniform mat4 osg_ModelViewProjectionMatrix; uniform mat4 osg_ModelViewMatrix; layout(location = 0) in vec4 Vertex; layout(location = 2) in vec4 Normal; // Velocity layout(location = 3) in vec3 TexCoord; // TODO: is this the right layout location? out VertexData { vec4 color; vec3 velocity; float size; } VertexOut; void main(void) { vec4 p0 = Vertex; vec4 p1 = Vertex + vec4(Normal.x, Normal.y, Normal.z, 0.0f); vec3 velocity = (osg_ModelViewProjectionMatrix * p1 - osg_ModelViewProjectionMatrix * p0).xyz; VertexOut.velocity = velocity; VertexOut.size = TexCoord.y; gl_Position = osg_ModelViewMatrix * Vertex; } What works is the Vertex and Normal information that the legacy C++ OpenGL code seem to provide in layout location 0 and 2. This is fine.
      What I'm not getting to work is the TexCoord information that is supplied by a glTexCoordPointer() call in C++.
      Question:
      What layout location is the old standard pipeline using for glTexCoordPointer()? Or is this undefined?
       
      Side note: I'm trying to get an OpenSceneGraph 3.4.0 particle system to use custom vertex, geometry and fragment shaders for rendering the particles.
    • By markshaw001
      Hi i am new to this forum  i wanted to ask for help from all of you i want to generate real time terrain using a 32 bit heightmap i am good at c++ and have started learning Opengl as i am very interested in making landscapes in opengl i have looked around the internet for help about this topic but i am not getting the hang of the concepts and what they are doing can some here suggests me some good resources for making terrain engine please for example like tutorials,books etc so that i can understand the whole concept of terrain generation.
       
    • By KarimIO
      Hey guys. I'm trying to get my application to work on my Nvidia GTX 970 desktop. It currently works on my Intel HD 3000 laptop, but on the desktop, every bind textures specifically from framebuffers, I get half a second of lag. This is done 4 times as I have three RGBA textures and one depth 32F buffer. I tried to use debugging software for the first time - RenderDoc only shows SwapBuffers() and no OGL calls, while Nvidia Nsight crashes upon execution, so neither are helpful. Without binding it runs regularly. This does not happen with non-framebuffer binds.
      GLFramebuffer::GLFramebuffer(FramebufferCreateInfo createInfo) { glGenFramebuffers(1, &fbo); glBindFramebuffer(GL_FRAMEBUFFER, fbo); textures = new GLuint[createInfo.numColorTargets]; glGenTextures(createInfo.numColorTargets, textures); GLenum *DrawBuffers = new GLenum[createInfo.numColorTargets]; for (uint32_t i = 0; i < createInfo.numColorTargets; i++) { glBindTexture(GL_TEXTURE_2D, textures[i]); GLint internalFormat; GLenum format; TranslateFormats(createInfo.colorFormats[i], format, internalFormat); // returns GL_RGBA and GL_RGBA glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, createInfo.width, createInfo.height, 0, format, GL_FLOAT, 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); DrawBuffers[i] = GL_COLOR_ATTACHMENT0 + i; glBindTexture(GL_TEXTURE_2D, 0); glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, textures[i], 0); } if (createInfo.depthFormat != FORMAT_DEPTH_NONE) { GLenum depthFormat; switch (createInfo.depthFormat) { case FORMAT_DEPTH_16: depthFormat = GL_DEPTH_COMPONENT16; break; case FORMAT_DEPTH_24: depthFormat = GL_DEPTH_COMPONENT24; break; case FORMAT_DEPTH_32: depthFormat = GL_DEPTH_COMPONENT32; break; case FORMAT_DEPTH_24_STENCIL_8: depthFormat = GL_DEPTH24_STENCIL8; break; case FORMAT_DEPTH_32_STENCIL_8: depthFormat = GL_DEPTH32F_STENCIL8; break; } glGenTextures(1, &depthrenderbuffer); glBindTexture(GL_TEXTURE_2D, depthrenderbuffer); glTexImage2D(GL_TEXTURE_2D, 0, depthFormat, createInfo.width, createInfo.height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glBindTexture(GL_TEXTURE_2D, 0); glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthrenderbuffer, 0); } if (createInfo.numColorTargets > 0) glDrawBuffers(createInfo.numColorTargets, DrawBuffers); else glDrawBuffer(GL_NONE); if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) std::cout << "Framebuffer Incomplete\n"; glBindFramebuffer(GL_FRAMEBUFFER, 0); width = createInfo.width; height = createInfo.height; } // ... // FBO Creation FramebufferCreateInfo gbufferCI; gbufferCI.colorFormats = gbufferCFs.data(); gbufferCI.depthFormat = FORMAT_DEPTH_32; gbufferCI.numColorTargets = gbufferCFs.size(); gbufferCI.width = engine.settings.resolutionX; gbufferCI.height = engine.settings.resolutionY; gbufferCI.renderPass = nullptr; gbuffer = graphicsWrapper->CreateFramebuffer(gbufferCI); // Bind glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo); // Draw here... // Bind to textures glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, textures[0]); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, textures[1]); glActiveTexture(GL_TEXTURE2); glBindTexture(GL_TEXTURE_2D, textures[2]); glActiveTexture(GL_TEXTURE3); glBindTexture(GL_TEXTURE_2D, depthrenderbuffer); Here is an extract of my code. I can't think of anything else to include. I've really been butting my head into a wall trying to think of a reason but I can think of none and all my research yields nothing. Thanks in advance!
    • By Adrianensis
      Hi everyone, I've shared my 2D Game Engine source code. It's the result of 4 years working on it (and I still continue improving features ) and I want to share with the community. You can see some videos on youtube and some demo gifs on my twitter account.
      This Engine has been developed as End-of-Degree Project and it is coded in Javascript, WebGL and GLSL. The engine is written from scratch.
      This is not a professional engine but it's for learning purposes, so anyone can review the code an learn basis about graphics, physics or game engine architecture. Source code on this GitHub repository.
      I'm available for a good conversation about Game Engine / Graphics Programming
    • By C0dR
      I would like to introduce the first version of my physically based camera rendering library, written in C++, called PhysiCam.
      Physicam is an open source OpenGL C++ library, which provides physically based camera rendering and parameters. It is based on OpenGL and designed to be used as either static library or dynamic library and can be integrated in existing applications.
       
      The following features are implemented:
      Physically based sensor and focal length calculation Autoexposure Manual exposure Lense distortion Bloom (influenced by ISO, Shutter Speed, Sensor type etc.) Bokeh (influenced by Aperture, Sensor type and focal length) Tonemapping  
      You can find the repository at https://github.com/0x2A/physicam
       
      I would be happy about feedback, suggestions or contributions.

  • Popular Now