Question

试图找到一种使用OpenGL在Java中渲染简单2D图像的方法我偶然发现了一个或多或少可理解的类，它为您完成了所有图像加载，我无法理解该怎么做。我相信它属于一个名叫Krythic的人，我认为它工作得很好，我甚至提出了它正在读取的图像的高度和宽度，看它是否能读出正确的图像。但是这里仍然是上课（我不完全理解它是如何工作的）：

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.nio.ByteBuffer;

import javax.imageio.ImageIO;

import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.GL12;

import static org.lwjgl.opengl.GL11.*;

public class TextureLoader {
    private static final int BYTES_PER_PIXEL = 4;//3 for RGB, 4 for RGBA
    public static int loadTexture(BufferedImage image){
    int[] pixels = new int[image.getWidth() * image.getHeight()];

    image.getRGB(0, 0, image.getWidth(), image.getHeight(), pixels, 0, image.getWidth());

    ByteBuffer buffer = BufferUtils.createByteBuffer(image.getWidth() * image.getHeight() * BYTES_PER_PIXEL); //4 for RGBA, 3 for RGB

    for(int y = 0; y < image.getHeight(); y++){
        for(int x = 0; x < image.getWidth(); x++){
            int pixel = pixels[y * image.getWidth() + x];
            buffer.put((byte) ((pixel >> 16) & 0xFF));     // Red component
            buffer.put((byte) ((pixel >> 8) & 0xFF));      // Green component
            buffer.put((byte) (pixel & 0xFF));               // Blue component
            buffer.put((byte) ((pixel >> 24) & 0xFF));    // Alpha component. Only for RGBA
        }
    }

    buffer.flip(); //FOR THE LOVE OF GOD DO NOT FORGET THIS

    // You now have a ByteBuffer filled with the color data of each pixel.
    // Now just create a texture ID and bind it. Then you can load it using
    // whatever OpenGL method you want, for example:

    int textureID = glGenTextures(); //Generate texture ID
    glBindTexture(GL_TEXTURE_2D, textureID); //Bind texture ID

    //Setup wrap mode
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL12.GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE);

    //Setup texture scaling filtering
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

    //Send texel data to OpenGL
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, image.getWidth(), image.getHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, buffer);

    //Return the texture ID so we can bind it later again
    return textureID;
}

public static BufferedImage loadImage(String loc)
{
    try {
        return ImageIO.read(Main.class.getResource(loc));
    } catch (IOException e) {
        //Error Handling Here
    }
    return null;
}

以下是我写的代码，认为它会将图像呈现在四边形上，这可能就是问题所在。

while ( glfwWindowShouldClose(window) == GL_FALSE ) {
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            BufferedImage image = TextureLoader.loadImage("test.png");
            int textureID = TextureLoader.loadTexture(image);
            glBindTexture(GL_TEXTURE_2D, textureID);
            glBegin(GL_QUADS);               
            glTexCoord2f(0, 0);
            glVertex2f(-1f, -1f);
            glTexCoord2f(1, 0);
            glVertex2f( 0f, -1f);
            glTexCoord2f(1, 1);
            glVertex2f( 0f,  0f);
            glTexCoord2f(0, 1);
            glVertex2f(-1f,  0f);
            glEnd();

            glfwSwapBuffers(window);

            glfwPollEvents();
        }

因此它在屏幕的左下角绘制一个四边形，就像之前一样，但它是白色的，纹理应该是棕色的。它没有给我任何例外，所以我不确切地知道我搞砸了。

Answer 1

使用

启用纹理

glEnable(GL_TEXTURE_2D);

需要帮助找出纹理不加载的原因

1 个答案: