Author: varone

Hello,

I have simple problem for professionalist (that i think ) but i asked all available AI about it and none was able to help and solve problem. so nothing is able to help me in this.

I have simple app that show 3 colored axes and camera that move around this scene by mouse click-hold . the problem is that after run appear first white backfround of frame for a second then its normal black background. i dont want this white at beginning.
can you tell me what in code change to get rid of this white flash at beginning ? I tried already plenty things.

This is the project code IntellJ, java , maven , with additional newest libraries lwjgl (lwjgl-release-3.31) and joml ( joml-1.10.61 ), this is whole code of 3d opengl - app 2 classes : Main and Camera , code is :

package org.example;

import org.joml.Matrix4f;
import org.lwjgl.glfw.GLFWVidMode;
import org.lwjgl.glfw.GLFWErrorCallback;
import org.lwjgl.opengl.GL;
import org.lwjgl.system.MemoryStack;

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

import static org.lwjgl.glfw.Callbacks.glfwFreeCallbacks;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.system.MemoryStack.stackPush;
import static org.lwjgl.system.MemoryUtil.NULL;

public class Main {

    private long window;
    private Camera camera;
    private float lastMouseX, lastMouseY;
    private boolean firstMouse = true;
    private boolean mousePressed = false;

    public void run() {
        init();
        loop();

        glfwFreeCallbacks(window);
        glfwDestroyWindow(window);

        glfwTerminate();
        Objects.requireNonNull(glfwSetErrorCallback(null)).free();
    }

    private void init() {
        GLFWErrorCallback.createPrint(System.err).set();

        if (!glfwInit()) {
            throw new IllegalStateException("Unable to initialize GLFW");
        }

        glfwDefaultWindowHints();
        glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
        glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
        // Request a double-buffered window
        glfwWindowHint(GLFW_DOUBLEBUFFER, GL_TRUE);

        window = glfwCreateWindow(800, 600, "3D Scene", NULL, NULL);
        if (window == NULL) {
            throw new RuntimeException("Failed to create the GLFW window");
        }

        glfwSetCursorPosCallback(window, (window, xpos, ypos) -> {
            if (firstMouse) {
                lastMouseX = (float) xpos;
                lastMouseY = (float) ypos;
                firstMouse = false;
            }

            if (mousePressed) {
                float dx = (float) xpos - lastMouseX;
                float dy = (float) ypos - lastMouseY;
                lastMouseX = (float) xpos;
                lastMouseY = (float) ypos;

                camera.rotate(dy * 0.1f, dx * 0.1f);
            }
        });

        glfwSetMouseButtonCallback(window, (window, button, action, mods) -> {
            if (button == GLFW_MOUSE_BUTTON_LEFT) {
                if (action == GLFW_PRESS) {
                    mousePressed = true;
                    firstMouse = true; // Reset firstMouse when the button is pressed
                } else if (action == GLFW_RELEASE) {
                    mousePressed = false;
                }
            }
        });

        glfwSetScrollCallback(window, (window, xoffset, yoffset) -> {
            camera.zoom((float) yoffset * -0.5f);
        });

        glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
            if (key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE) {
                glfwSetWindowShouldClose(window, true);
            }
        });

        try (MemoryStack stack = stackPush()) {
            IntBuffer pWidth = stack.mallocInt(1);
            IntBuffer pHeight = stack.mallocInt(1);

            glfwGetWindowSize(window, pWidth, pHeight);

            GLFWVidMode vidmode = glfwGetVideoMode(glfwGetPrimaryMonitor());

            glfwSetWindowPos(
                    window,
                    (vidmode.width() - pWidth.get(0)) / 2,
                    (vidmode.height() - pHeight.get(0)) / 2
            );
        }

        glfwMakeContextCurrent(window);
        glfwSwapInterval(1);
        glfwShowWindow(window);

        GL.createCapabilities();

        glEnable(GL_DEPTH_TEST);

        // Set the projection matrix
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        float aspectRatio = 800.0f / 600.0f;
        glFrustum(-aspectRatio, aspectRatio, -1, 1, 1, 100);

        camera = new Camera(20, 30, 45);
    }

    private void loop() {
        // Set the clear color explicitly
        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

        while (!glfwWindowShouldClose(window)) {
            // Clear the color and depth buffers
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

            Matrix4f viewMatrix = camera.getViewMatrix();
            FloatBuffer fb = org.lwjgl.BufferUtils.createFloatBuffer(16);
            viewMatrix.get(fb);

            glMatrixMode(GL_MODELVIEW);
            glLoadMatrixf(fb);

            drawAxes();

            glfwSwapBuffers(window);
            glfwPollEvents();
        }
    }


    private void drawAxes() {
        glBegin(GL_LINES);

        // X axis in red
        glColor3f(1.0f, 0.0f, 0.0f);
        glVertex3f(-20.0f, 0.0f, 0.0f);
        glVertex3f(20.0f, 0.0f, 0.0f);

        // Y axis in green
        glColor3f(0.0f, 1.0f, 0.0f);
        glVertex3f(0.0f, -20.0f, 0.0f);
        glVertex3f(0.0f, 20.0f, 0.0f);

        // Z axis in yellow
        glColor3f(1.0f, 1.0f, 0.0f);
        glVertex3f(0.0f, 0.0f, -20.0f);
        glVertex3f(0.0f, 0.0f, 20.0f);

        glEnd();
    }

    public static void main(String[] args) {
        new Main().run();
    }
}

and Camera code :

package org.example;
import org.joml.Matrix4f;
import org.joml.Vector3f;

public class Camera {

private Vector3f position;
private float pitch;
private float yaw;
private float distance;

public Camera(float distance, float pitch, float yaw) {
    this.position = new Vector3f(0, 0, 0);
    this.pitch = pitch;
    this.yaw = yaw;
    this.distance = distance;
}

public Matrix4f getViewMatrix() {
    Matrix4f viewMatrix = new Matrix4f();
    viewMatrix.identity();

    // Calculate the camera position based on spherical coordinates
    float x = (float) (distance * Math.sin(Math.toRadians(pitch)) * Math.cos(Math.toRadians(yaw)));
    float y = (float) (distance * Math.cos(Math.toRadians(pitch)));
    float z = (float) (distance * Math.sin(Math.toRadians(pitch)) * Math.sin(Math.toRadians(yaw)));

    position.set(x, y, z);

    viewMatrix.lookAt(position, new Vector3f(0, 0, 0), new Vector3f(0, 1, 0));
    return viewMatrix;
}

public void rotate(float pitchDelta, float yawDelta) {
    this.pitch += pitchDelta;
    this.yaw += yawDelta;
}

public void zoom(float distanceDelta) {
    this.distance += distanceDelta;
    if (this.distance < 1.0f) {
        this.distance = 1.0f; // Prevent camera from getting too close
    }
}

public Vector3f getPosition() {
    return position;
}

public float getPitch() {
    return pitch;
}

public float getYaw() {
    return yaw;
}

public float getDistance() {
    return distance;
}


}

and pom.xml file is :

4.0.0
<groupId>org.example</groupId>
<artifactId>3dscene</artifactId>
<version>1.0-SNAPSHOT</version>

<properties>
    <maven.compiler.source>17</maven.compiler.source>
    <maven.compiler.target>17</maven.compiler.target>
</properties>

<dependencies>
    <!-- LWJGL dependencies -->
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl</artifactId>
        <version>3.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl-glfw</artifactId>
        <version>3.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl-opengl</artifactId>
        <version>3.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl-stb</artifactId>
        <version>3.3.1</version>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl</artifactId>
        <version>3.3.1</version>
        <classifier>natives-windows</classifier>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl-glfw</artifactId>
        <version>3.3.1</version>
        <classifier>natives-windows</classifier>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl-opengl</artifactId>
        <version>3.3.1</version>
        <classifier>natives-windows</classifier>
    </dependency>
    <dependency>
        <groupId>org.lwjgl</groupId>
        <artifactId>lwjgl-stb</artifactId>
        <version>3.3.1</version>
        <classifier>natives-windows</classifier>
    </dependency>

    <!-- JOML dependency -->
    <dependency>
        <groupId>org.joml</groupId>
        <artifactId>joml</artifactId>
        <version>1.10.5</version>
    </dependency>
</dependencies>

<repositories>
    <repository>
        <id>sonatype</id>
        <url>https://oss.sonatype.org/content/repositories/snapshots/</url>
    </repository>
</repositories>