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#81

Lightweight Java Gaming Library / SOLVED - LWJGL <--> Renderdoc ...

Last post by bmcclint - March 31, 2024, 17:05:27

All,

This is my first post and a stab in the dark while I attempt to debug whats going on.  If this is better in the OpenGL topic OR on the RenderDoc platform please let me know.

OK...I am attempting to debug an existing application I've been tinkering with for years now in RenderDoc as I am trying to see whats going on in several of the off screen textures I am rendering to.  The application is using LWGJL 3.3.3-snapshot(also tried 3.3.2-snapshot) and Java 17.  Its a Gradle project and I am currently working on a Ubuntu install.  The project works, builds, runs and the like.  I can command line execute the jar or debug via an IDE and life is grand.  So I seem to think the java application is correct.  Note...I hooked up a C++ GLFW/Cmake variant the RenderDoc runs that code.

When attempting to run via RenderDoc, with the JVM path set, working folder and command line args, RenderDoc does seem to start my application.  I see the window appear, the console where RenderDoc loads is showing the log output, OpenGL version, OpenAL, etc (see below)...then when the scene loads and attempts to compile its first shader it throws an exception and aborts.  Error is...

FATAL ERROR in native method: Thread[main,5,main]: No context is current or a function that is not available in the current context was called. The JVM will abort execution.
   at org.lwjgl.opengl.ARBShaderObjects.glCreateShaderObjectARB(Native Method)
   at com.bbs.platform.desktop.drivers.OpenGLDriver.glCreateShader(OpenGLDriver.java:492)
   at com.bbs.engine.graphics.opengl.GLSL.CompileShader(GLSL.java:140)
   at com.bbs.engine.graphics.opengl.GLSL.CompileVertexShader(GLSL.java:122)
   at com.bbs.engine.shader.ShaderProgram.CompileVertexShaders(ShaderProgram.java:162)
   at com.bbs.engine.asset.shader.DiffusePhong.Compile(DiffusePhong.java:25)
...

...it seems that the OpenGL context is either gone, on another thread or RenderDoc just cannot access it.  From the first parts of the log, LWJGL is detected, versions captured and OpenGL contexts seem to be in play.  As stated, when running in RenderDoc I see the window and the title appear, stay up for a second or so then close.  I assume that's the stack dump process casing the delay.

Question...Anyone know what might be wrong?  Do I need an addl JVM switch?  Different version?  I will strip down to a boiler plate example project but that's going to take some time as it appears to 'find' OpenGL and query strings, versions, the shader is where we fail, so I will need to build a skeleton and keep addling the layers till we get to the stopping point.  This is my quick attempt at 'what am I missing?' type post.  As noted, C++ variant is fine so RenderDoc is at least installed correctly.

Insight greatly appreciated...

*** condensed version of the log...
19.317Z : INFO  : .platform.desktop.MainActivity - Host OS: Linux
19.325Z : INFO  : .platform.desktop.MainActivity - LWJGL V: 3.3.3-snapshot
19.365Z : INFO  : .platform.desktop.MainActivity - GLFW V: 3.4.0 Wayland X11 GLX Null EGL OSMesa monotonic shared
19.365Z : INFO  : .platform.desktop.MainActivity - Java Version: 17.0.10+7-Ubuntu-122.04.1; Processors: 8
19.560Z : INFO  : .platform.desktop.MainActivity - Created GLTF Window: 'HemetTV'
19.575Z : INFO  : .platform.desktop.MainActivity - Display VSYNC Enabled: true
19.620Z : INFO  : com.bbs.app.hemettv.VREngine   - ===============================================================================
19.620Z : INFO  : com.bbs.app.hemettv.VREngine   - Create Engine: 'VREngine'
19.620Z : INFO  : com.bbs.app.hemettv.VREngine   - = = = = = = = = = = = = = = = = = = = = = = =
19.908Z : INFO  : m.desktop.drivers.OpenALDriver - Desktop OpenAL(JWJGL) sound system initialized.
19.909Z : INFO  : m.desktop.drivers.OpenALDriver - Vendor = OpenAL Community
19.909Z : INFO  : m.desktop.drivers.OpenALDriver - Renderer = OpenAL Soft
19.909Z : INFO  : m.desktop.drivers.OpenALDriver - Version = 1.1 ALSOFT 1.23.1
19.909Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_MAJOR_VERSION: 1
19.910Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_MINOR_VERSION: 1
19.910Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_FREQUENCY: 44100
19.910Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_REFRESH: 50
19.910Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_SYNC: 0
19.910Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_MONO_SOURCES: 255
19.910Z : INFO  : m.desktop.drivers.OpenALDriver - ALC_STEREO_SOURCES: 1
19.940Z : INFO  : com.bbs.app.hemettv.VREngine   - toggleStereoscopic: false
19.941Z : INFO  : com.bbs.app.hemettv.VREngine   - toggleVirtualControls: false
19.965Z : INFO  : bbs.engine.manager.FileManager - FileManager::Successfully loaded data folder: ./Data/
19.967Z : INFO  : bs.engine.graphics.opengl.GLES - GL version:   4.6.0 NVIDIA 535.161.07
19.967Z : INFO  : bs.engine.graphics.opengl.GLES - GL vendor:   NVIDIA Corporation
19.967Z : INFO  : bs.engine.graphics.opengl.GLES - GL renderer:   NVIDIA GeForce RTX 2060/PCIe/SSE2
19.967Z : INFO  : bs.engine.graphics.opengl.GLES - GLSL version:   4.60 NVIDIA
19.968Z : INFO  : bs.engine.graphics.opengl.GLES - GLSL version tag:   #version 460
19.968Z : INFO  : bs.engine.graphics.opengl.GLES - GLSL extensions:   
20.081Z : INFO  : bs.app.hemettv.scene.BaseScene - -------------------------------------------------------------------------------
20.081Z : INFO  : bs.app.hemettv.scene.BaseScene - Creating scene: 'HDRBloom'
FATAL ERROR in native method: Thread[main,5,main]: No context is current or a function that is not available in the current context was called. The JVM will abort execution.
...

#82

OpenGL / Re: First steps with LWJGL and...

Last post by stuck1a - March 24, 2024, 21:03:01

Heureka, I finally found the issue myself 

The problem was, that I've called glfwSwapBuffers() before the renderer (instead of after) within the renderloop.

For all those who have similar problems and end up here via google, I'd like to point out the following excellent tutorial. which uses OpenGL under C++, but which can be easily transferred to Java/LWJGL and is the only tutorial I know that shows the complete render process in detail.

Best regards,
stuck1a

#83

OpenGL / Re: First steps with LWJGL and...

Last post by stuck1a - March 24, 2024, 09:27:43

In the meantime, I implemented a few more validations and combined all the code into a single class for the sake of simplicity.
Compiling and linking of the shaders works, but for some reason, the JVM crashes with exit code -1073741819 (0xC0000005) everytime it comes to  glDrawArrays(), but I don't know why. As you can see in the code, both, the buffer and the shader is set.

This is the complete sequence:

Code: Class "Deadzone"

public class Deadzone {
  public static void main(String[] args) throws InterruptedException {
    TestForOpenGL testing = new TestForOpenGL();
    try {
      testing.executeTest();
    } catch (java.lang.Exception e) {
      System.err.println(e.getMessage());
    }
  }
}

Code: Class "TestForOpenGL"

import org.lwjgl.glfw.GLFWErrorCallback;
import org.lwjgl.glfw.GLFWVidMode;
import org.lwjgl.opengl.GL;
import org.lwjgl.system.MemoryStack;

import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.util.Objects;

import static java.lang.Thread.sleep;
import static org.lwjgl.glfw.Callbacks.glfwFreeCallbacks;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL20.*;
import static org.lwjgl.opengl.GL30.*;
import static org.lwjgl.system.MemoryStack.stackPush;
import static org.lwjgl.system.MemoryUtil.NULL;

public class TestForOpenGL {
  private long windowId;
  
  private int shaderProgramId = 0;
  private int vertexShaderId = 0;
  private int fragmentShaderId = 0;
  
  private int vaoId = 0;
  private int vboId = 0;
  
  
  public void executeTest() throws Exception {
    // Initialize LWJGL
    GLFWErrorCallback errorCallback = GLFWErrorCallback.createPrint(System.err);
    glfwSetErrorCallback(errorCallback);
    if ( !glfwInit() ) throw new IllegalStateException("Unable to initialize GLFW");
    
    // Create render context (the application window)
    glfwDefaultWindowHints();
    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
    glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
    windowId = glfwCreateWindow(800, 600, "Render test", NULL, NULL);
    if ( windowId == NULL ) {
      glfwTerminate();
      throw new RuntimeException("Failed to create the GLFW window");
    }
    try ( MemoryStack stack = stackPush() ) {
      IntBuffer pWidth = stack.mallocInt(1);
      IntBuffer pHeight = stack.mallocInt(1);
      glfwGetWindowSize(windowId, pWidth, pHeight);
      GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());
      assert vidmode != null;
      glfwSetWindowPos(windowId, (vidmode.width() - pWidth.get(0)) / 2, (vidmode.height() - pHeight.get(0)) / 2);
    }
    glfwMakeContextCurrent(windowId);
    glfwSwapInterval(1);
    glfwShowWindow(windowId);
    GL.createCapabilities();
    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    
    // Render loop
    while ( !glfwWindowShouldClose(windowId) ) {
      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
      glfwSwapBuffers(windowId);
      glfwPollEvents();
      render();
      sleep(1000L / 30L);
    }

    // Shutdown
    glfwFreeCallbacks(windowId);
    glfwDestroyWindow(windowId);
    glfwTerminate();
    Objects.requireNonNull(glfwSetErrorCallback(null)).free();
  }
  
  
  private void render() throws Exception {
    /* Set up the shader program, if not done yet */
    if (shaderProgramId == 0) {
      try {
        shaderProgramId = glCreateProgram();
        if (shaderProgramId == 0) throw new Exception("Could not create shader program");
        
        // Create, compile and attach vertex shader
        String vertexShaderCode =
          "#version 150 core\n" +
          "in vec2 position;\n" +
          "in vec3 color;\n" +
          "out vec3 vertexColor;\n" +
          "void main() { vertexColor = color; gl_Position = vec4(position, 0.0, 1.0); }";
        vertexShaderId = glCreateShader(GL_VERTEX_SHADER);
        if (vertexShaderId == 0) throw new RuntimeException("Failed to create vertex shader!");
        glShaderSource(vertexShaderId, vertexShaderCode);
        glCompileShader(vertexShaderId);
        if (glGetShaderi(vertexShaderId, GL_COMPILE_STATUS) == 0) throw new RuntimeException("Error compiling vertex shader!\n" + glGetShaderInfoLog(vertexShaderId, 1024));
        glAttachShader(shaderProgramId, vertexShaderId);
        
        // Create, compile and attach fragment shader
        String fragmentShaderCode =
          "#version 150 core\n\n" +
          "in vec3 vertexColor;\n\n" +
          "out vec4 outColor;\n\n" +
          "void main() { outColor = vec4(vertexColor, 1.0);}";
        fragmentShaderId = glCreateShader(GL_FRAGMENT_SHADER);
        if (fragmentShaderId == 0) throw new RuntimeException("Failed to create fragment shader!");
        glShaderSource(fragmentShaderId, fragmentShaderCode);
        glCompileShader(fragmentShaderId);
        if (glGetShaderi(fragmentShaderId, GL_COMPILE_STATUS) == 0) throw new RuntimeException("Error compiling fragment shader!\n" + glGetShaderInfoLog(fragmentShaderId, 1024));
        glAttachShader(shaderProgramId, fragmentShaderId);
      } catch (Exception e) {
        System.err.println("Could not initialize shaders.\n" + e.getMessage());
      }
    }
    
    // Link shader program and detach shaders from RAM
    glLinkProgram(shaderProgramId);
    if (glGetProgrami(shaderProgramId, GL_LINK_STATUS) == 0) throw new Exception("Error linking shader");
    glDetachShader(shaderProgramId, vertexShaderId);
    glDetachShader(shaderProgramId, fragmentShaderId);
  
    // Validate shaders
    glValidateProgram(shaderProgramId);
    if (glGetProgrami(shaderProgramId, GL_VALIDATE_STATUS) == 0) {
      System.err.println("Failed to validate shaders");
    }
    
    // Prepare and use shader program
    glBindFragDataLocation(shaderProgramId, 0, "outColor");
    glUseProgram(shaderProgramId);
    
    /* VAO */
    vaoId = glGenVertexArrays();
    glBindVertexArray(vaoId);
    
    /* VBO */
    float[] triangleInput = {
      // x     y   R   G   B
      0.5f, 0.9f, 1f, 0f, 0f,  // Point A
      0.1f, 0.1f, 1f, 0f, 0f,  // Point B
      0.9f, 0.1f, 1f, 0f, 0f   // Point C
    };
    MemoryStack stack = MemoryStack.stackPush();
    FloatBuffer vertices = stack.mallocFloat(triangleInput.length);
    for (float val : triangleInput) {
      vertices.put(val);
    }
    vertices.flip();
    
    // Bind VBO
    vboId = glGenBuffers();
    glBindBuffer(GL_ARRAY_BUFFER, vboId);
    
    // Upload vertices to the GPU
    glBufferData(GL_ARRAY_BUFFER, vertices, GL_STATIC_DRAW);
    MemoryStack.stackPop();
  
    // Specify vertex attributes
    int positionAttribute = glGetAttribLocation(shaderProgramId, "position");
    glEnableVertexAttribArray(positionAttribute);
    glVertexAttribPointer(positionAttribute, 2, GL_FLOAT, false, 0, 0);
    int colorAttribute = glGetAttribLocation(shaderProgramId, "color");
    glEnableVertexAttribArray(colorAttribute);
    glVertexAttribPointer(colorAttribute, 3, GL_FLOAT, false, 0, 2 * Float.BYTES);
    
    /* Draw the triangle */
    glClear(GL_COLOR_BUFFER_BIT);
    glDrawArrays(GL_TRIANGLES, 0, 3);
  
    /* Free resources */
    glDeleteBuffers(vboId);
    glDeleteVertexArrays(vaoId);
    if (vertexShaderId != 0) glDeleteShader(vertexShaderId);
    if (fragmentShaderId != 0) glDeleteShader(fragmentShaderId);
    glUseProgram(0);
    if (shaderProgramId != 0) glDeleteProgram(shaderProgramId);
  }
  
}

Here you can see the Test Class with syntax highlighting:
https://github.com/stuck1a/deadzone/blob/main/src/deadzone/TestForOpenGL.java

#84

OpenGL / [SOLVED] First steps with LWJG...

Last post by stuck1a - March 23, 2024, 18:33:23

Hello everyone,

I'm actually a web developer, so I haven't had much to do with OpenGL yet.
But I want to get into game development and because I already know Java, it was obvious for me to make my first attempts with LWJGL.

I have implemented the basic structure for my game project and am now trying to render a triangle with the help of thistutorial. No exception is thrown during execution, but nothing is rendered either. The tutorial mentions that you have to bind the VertexBufferObjects to a VertexArrayObject, but unfortunately the tutorial does not explain how this is done. The linked repository differs greatly from the tutorial, so I cannot derive this from it.
Since I'm stuck at this point for two days now, I hope someone here can help me out.


I've shortened the code as good as possible. In my render loop, I simply call drawTriangle() once.
The renderer object is created once on game initialization. As you can see, it will compile and bind the shaders.

Code: Class Renderer

public class Renderer {
  protected ShaderProgram shaders;
  ArrayList<VertexBufferObject> registeredVboObjects = new ArrayList<>();
  ArrayList<VertexArrayObject> registeredVaoObjects = new ArrayList<>();

  public Renderer() {
    if (shaders == null) {
      try {
        shaders = new ShaderProgram();
        shaders.initializeBaseShaders();
        shaders.bind();
      } catch (Exception e) {
        System.err.println("Could not initialize shaders.\n" + e.getMessage());
        return;
      }
    }
  }

  private void drawTriangle() {
    VertexArrayObject vaoTriangle1 = new VertexArrayObject();
    vaoTriangle1.initialize();

    VertexBufferObject vboTriangle1 = new VertexBufferObject(
      new float[]{
        0.5f, 1.0f, 0.0f, 1f, 0f, 0f,
        0.0f, 0.0f, 0.0f, 0f, 1f, 0f,
        1.0f, 0.0f, 0.0f, 0f, 0f, 1f
      }
    );
    vboTriangle1.initialize();
    
    // TODO: Bind the VBO to the VAO ???
    
    // Register all objects related to the triangle
    registeredVboObjects.add(vboTriangle1);
    registeredVaoObjects.add(vaoTriangle1);
    
    // Draw the Triangle
    vboTriangle1.render();
  }
}

Code: Class ShaderProgram

public class ShaderProgram {
  private final int programId;
  private int vertexShaderId;
  private int fragmentShaderId;
  
  public ShaderProgram() throws Exception {
    programId = glCreateProgram();
    if (programId == 0) {
      throw new Exception("Could not create Shader");
    }
  }
  
  public int getProgramId() {
    return programId;
  }
  
  public int getVertexShaderId() {
    return vertexShaderId;
  }
  
  public int getFragmentShaderId() {
    return fragmentShaderId;
  }
  
  public void bind() {
    glUseProgram(programId);
  }
  
  public void unbind() {
    glUseProgram(0);
  }
  
  public void link() throws Exception {
    glLinkProgram(programId);
    if (glGetProgrami(programId, GL_LINK_STATUS) == 0) {
      throw new Exception("Error linking Shader code: " + glGetProgramInfoLog(programId, 1024));
    }
    if (vertexShaderId != 0) glDetachShader(programId, vertexShaderId);
    if (fragmentShaderId != 0) glDetachShader(programId, fragmentShaderId);
  }
  
  public void initializeBaseShaders() throws Exception {
    String shadersDir = Util.getShadersDir();
    String vertexShaderCode = Util.readFullFile(shadersDir + "vertex.glsl");
    vertexShaderId = compileShader(vertexShaderCode, GL_VERTEX_SHADER);
    String fragmentShaderCode = Util.readFullFile(shadersDir + "fragment.glsl");
    fragmentShaderId = compileShader(fragmentShaderCode, GL_FRAGMENT_SHADER);
    link();
  }
  
  public int compileShader(String shaderCode, int shaderType) throws Exception {
    int shaderId = glCreateShader(shaderType);
    if (shaderId == 0) throw new RuntimeException("Error creating shader. Type: " + shaderType);
    glShaderSource(shaderId, shaderCode);
    glCompileShader(shaderId);
    if (glGetShaderi(shaderId, GL_COMPILE_STATUS) == 0) {
      throw new RuntimeException("Error compiling Shader code: " + glGetShaderInfoLog(shaderId, 1024));
    }
    glAttachShader(programId, shaderId);
    return shaderId;
  }
}

Code: Class VertexArrayObject

public class VertexArrayObject {
  private final int vaoId;
  
  public VertexArrayObject() {
    vaoId = glGenVertexArrays();
  }
  
  public void initialize() {
    bind();
  }
  
  public int getID() {
    return vaoId;
  }
  
  public void delete() {
    glDeleteVertexArrays(vaoId);
  }
  
  private void bind() {
    glBindVertexArray(vaoId);
  }
}

Code: Class VertexBufferObject

public class VertexBufferObject {
  private int vboId;
  MemoryStack stack;
  FloatBuffer vertices;
  
  public VertexBufferObject(float[] vertexData) {
    stack = MemoryStack.stackPush();
    vertices = stack.mallocFloat(vertexData.length);
    for (float val : vertexData) {
      vertices.put(val);
    }
    vertices.flip();
  }
  
  public void initialize() {
    vboId = glGenBuffers();
    bind(GL_ARRAY_BUFFER);
    uploadData(GL_ARRAY_BUFFER, vertices, GL_STATIC_DRAW);
    MemoryStack.stackPop();
    specifyVertexAttributes();
  }
  
  public void render() {
    glClear(GL_COLOR_BUFFER_BIT);
    glDrawArrays(GL_TRIANGLES, 0, 3);
  }
  
  public void delete() {
    glDeleteBuffers(vboId);
  }
  
  public int getID() {
    return vboId;
  }
  
  private void bind(int target) {
    glBindBuffer(target, vboId);
  }
  
  private void uploadData(int target, FloatBuffer data, int usage) {
    glBufferData(target, data, usage);
  }
  
  private void specifyVertexAttributes() {
    int shaderProgram = Deadzone.getApplication().getRenderer().getShaders().getProgramId();
    // position attribute
    int positionAttribute = glGetAttribLocation(shaderProgram, "position");
    glEnableVertexAttribArray(positionAttribute);
    glVertexAttribPointer(positionAttribute, 3, GL_FLOAT, false, 6 * Float.BYTES, 0);
    // color attribute
    int colorAttribute = glGetAttribLocation(shaderProgram, "color");
    glEnableVertexAttribArray(colorAttribute);
    glVertexAttribPointer(colorAttribute, 3, GL_FLOAT, false, 6 * Float.BYTES, 3 * Float.BYTES);
  }
}

Those are my shaders:

Code: vertex.glsl

#version 150 core

in vec2 position;
in vec3 color;

out vec3 vertexColor;

void main() {
  vertexColor = color;
  gl_Position = vec3(position, 1.0);
}

Code: fragment.glsl

#version 150 core

in vec3 vertexColor;

out vec4 outColor;

void main() {
  outColor = vec4(vertexColor, 1.0);
}

Perhaps somone here can help me and explain what is missing or what I am doing wrong?
The complete project repository can be viewed here.

Many thanks in advance and best regards,
stuck1a

#85

Lightweight Java Gaming Library / Re: Multisampling in OpenXR

Last post by Richtea - March 16, 2024, 21:23:01

I understand now I think. I need to render to a seperate frame buffer (that supports multisampling) then blit into a second frame buffers for OpenXR to use as its swapchain image

#86

Bug Reports / RFE / Re: [BUG] Rare and Random cras...

Last post by Lankyware - March 09, 2024, 13:02:34

I was able to stop the crashes. There were two different animation effects being batch rendered together, I split it into 2 separate draw calls and that got rid of the crashes for some reason.

#87

Lightweight Java Gaming Library / Re: Multisampling in OpenXR

Last post by Richtea - March 09, 2024, 11:56:34

edit; sorry, some how managed to quote reply myself rather than editing  Please ignore this reply

#88

Lightweight Java Gaming Library / Multisampling in OpenXR

Last post by Richtea - March 08, 2024, 12:07:26

I've been looking into trying to get MSAA antialiasing working within an OpenXR VR application.

I'm looking at how the swapchain images get created

                XrSwapchainCreateInfo swapchainCreateInfo = XrSwapchainCreateInfo.malloc(stack)
                        .type$Default()
                        .next(NULL)
                        .createFlags(0)
                        .usageFlags(XR10.XR_SWAPCHAIN_USAGE_SAMPLED_BIT | XR10.XR_SWAPCHAIN_USAGE_COLOR_ATTACHMENT_BIT)
                        .format(glColorFormat)
                        .sampleCount(viewConfig.recommendedSwapchainSampleCount()) //<--- interesting
                        .width(viewConfig.recommendedImageRectWidth())
                        .height(viewConfig.recommendedImageRectHeight())
                        .faceCount(1)
                        .arraySize(1)
                        .mipCount(1);

                PointerBuffer swapchainHanglePointerBuffer = stack.mallocPointer(1);
                checkResponseCode(XR10.xrCreateSwapchain(xrSession, swapchainCreateInfo, swapchainHanglePointerBuffer));

And looking at where recommendedSwapchainSampleCount comes from it is from asking the runtime for its opinion

            checkResponseCode(XR10.xrEnumerateViewConfigurationViews(xrInstance, systemID, viewConfigType, viewCountPointer, null));
            viewConfigs = XrUtils.fill(
                    XrViewConfigurationView.calloc(viewCountPointer.get(0)), // use calloc() rather than malloc() to ensure the next field is correctly initialized
                    XrViewConfigurationView.TYPE,
                    XR10.XR_TYPE_VIEW_CONFIGURATION_VIEW
            );

            checkResponseCode(XR10.xrEnumerateViewConfigurationViews(xrInstance, systemID, viewConfigType, viewCountPointer, viewConfigs));

And for my system `viewConfig.recommendedSwapchainSampleCount()` returns 1 (And setting anything else gives me a XR_ERROR_RUNTIME_FAILURE error code). But I don't understand why it's 1. My system aught to be able to support more than that (Its all done locally on the PC right, the headsets not doing the sampling right?); in non VR contexts antialiasing all works fine. (viewConfig.maxSwapchainSampleCount() also returns 1)

My system is:
Oculus Quest 2 running over Virtual Desktop
Windows 10
NVidea GeForce RTX 3070


Am I on the right track here? Any ideas as to how I can get MSAA  antialiasing working?

#89

Bug Reports / RFE / Re: [BUG] Rare and Random cras...

Last post by Lankyware - March 07, 2024, 23:09:43

Oh, I stopped using ByteBuffers. When I call glBufferData() I put in an array of floats. IIRC I did this because for some things in my game, I put new data in before every draw call, and using Buffer objects for that made it GC more often, causing microlags.

#90

Bug Reports / RFE / Re: [BUG] Rare and Random cras...

Last post by spasi - March 07, 2024, 18:16:43

Hey Lankyware,

Does it happen much earlier if you add System.gc() calls (say, once per frame) in your application? It would indicate that a direct ByteBuffer that is still in use is being garbage-collected, and its associated native memory freed, by mistake. Note that a major issue with GC-managed ByteBuffers (allocated with ByteBuffer.allocateDirect or BufferUtils in LWJGL) is that they are not freed unless full GC cycles happen. The JDK uses Cleaner for this, which is a PhantomReference. Weak/soft/phantom reference processing happens during full GC pauses with most GCs. Such pauses are kind of rare on modern JVMs and that can explain unpredictable crashes at a later time.

I hope this helps.