java - Opengl 多种纹理混合颜色

Question

为什么纹理的颜色是混合的？我该如何解决这个问题？

这就是我绘制和初始化的方式:

private void initGL_3D() {
    int width = Display.getWidth();
    int height = Display.getHeight();
    glLoadIdentity(); // Reset The Projection Matrix
    GLU.gluPerspective(45.0f, ((float) width / (float) height), 0.1f, 100.0f); // Calculate The Aspect Ratio Of The Window
    glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix

    glLoadIdentity(); // Reset The Modelview Matrix

    glShadeModel(GL_SMOOTH); // Enables Smooth Shading


    glClearDepth(1.0f); // Depth Buffer Setup
    glEnable(GL_DEPTH_TEST); // Enables Depth Testing
    glDepthFunc(GL_LEQUAL); // The Type Of Depth Test To Do
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations
}

private void initGL_2D() {
    int width = Display.getWidth();
    int height = Display.getHeight();

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0.0f, width, height, 0.0f, 1, -1);

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glDisable(GL_DEPTH_TEST);

    // Enable transparency
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

private void renderGL() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    int width = Display.getWidth();
    int height = Display.getHeight();

    glEnable(GL_TEXTURE_2D);

    glViewport(0, 0, width, height); // Reset The Current Viewport\
    glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
    if (game){
        glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // Black Background
        initGL_3D();
        renderGL_3D();
    }
    initGL_2D();
    renderGL_2D();
}

private void renderGL_3D() {
    glLoadIdentity();

    glTranslatef(0, 0f, -3f);

    glRotatef(rotationX, 1.0f,0.0f,0.0f);

    glRotatef(rotationY/4, 0.0f,1.0f,0.0f);

    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, texture1.getTextureID());

    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, texture2.getTextureID());

    glBegin(GL_TRIANGLES);
    glMultiTexCoord2f(GL_TEXTURE0, 0, 0);
    glVertex3f(0, 0, 0);

    glMultiTexCoord2f(GL_TEXTURE0, 1, 0);
    glVertex3f(1, 0, 0);

    glMultiTexCoord2f(GL_TEXTURE0, 0, 1);
    glVertex3f(0, 1, 0);

    glMultiTexCoord2f(GL_TEXTURE1, 1, 1);
    glVertex3f(1, 1, 0);

    glMultiTexCoord2f(GL_TEXTURE1, 1, 0);
    glVertex3f(1, 0, 0);

    glMultiTexCoord2f(GL_TEXTURE1, 0, 1);
    glVertex3f(0, 1, 0);
    glEnd();
}

private void renderGL_2D() {
    if (mainMenu) {
    gui.setBackground(0);
    glLoadIdentity();
    for (Button button : gui.buttons) {
        float posX;
        float posY;

        if (button.posX == "center") {
            posX = Display.getWidth()/2-button.width/2;
        } else {
            posX = Integer.parseInt(button.posX);
        }

        if (button.posY == "center") {
            posY = Display.getHeight()/2-button.height/2;
        } else {
            posY = Integer.parseInt(button.posY);
        }

        if(guiMouseX > posX && guiMouseY > posY && guiMouseX < posX + button.width && guiMouseY < posY + button.height){
            button.textureOver.bind();
            button.mouseOver.run();
            if (Mouse.isButtonDown(0)) {
                button.mouseDown.run();
            }
        } else {
            button.texture.bind();
        }

        float imageWidth = button.texture.getImageWidth();
        float textureWidth = button.width/imageWidth;
        float imageHeight = button.texture.getImageHeight();
        float textureHeight = button.height/imageHeight;

        glBegin(GL_QUADS);
        glTexCoord2f(0, 0);
        glVertex2f(posX, posY);
        glTexCoord2f(textureWidth, 0);
        glVertex2f(posX + button.width, posY);
        glTexCoord2f(textureWidth, textureHeight);
        glVertex2f(posX + button.width, posY + button.height);
        glTexCoord2f(0, textureHeight);
        glVertex2f(posX, posY + button.height);
        glEnd();
    }
    }
}

一切都画得很好，但唯一的问题是纹理颜色是混合的!

这就是我运行应用程序时纹理的样子

这些是具有正常颜色的纹理

和

Answer 1

因为您是从“renderGL”内部调用“renderGL_3D”。该函数绘制两个三角形，一个使用texture0，另一个使用texture1。

左下角三角形的第 0 级纹理坐标全为零。这使得它对绿色纹理的左上角进行采样，因此它也是绿色的。由于您已启用混合，因此第二个白色纹理会混合在顶部，使其全部变为绿色。

要对此进行测试，请尝试将白色纹理的左上角像素设为洋红色或其他易于区分的颜色。现在左下角的三角形应该是脏洋红色(由于过滤而混入了一些绿色)。

对于您的解决方案，您需要禁用多重纹理混合(不是 GL_BLEND - 它将光栅化器提供的最终颜色混合到帧缓冲区中)。您可以通过

来做到这一点

    glActiveTexture(GL_TEXTURE0);
    glTexEnvi(GL_TEXTURE_2D, GL_TEXTURE_ENV_MODE, GL_REPLACE);

纹理单元 1 也是如此

    glActiveTexture(GL_TEXTURE1);
    glTexEnvi(GL_TEXTURE_2D, GL_TEXTURE_ENV_MODE, GL_REPLACE);

这应该有效。