Question

我目前正在尝试在Android上制作游戏。我有这段代码，我试图在屏幕的一角显示正方形。我试过使用GLU.gluOrtho2D，但每次使用它时都会出现空白屏幕。有人能告诉我如何将正方形从屏幕中心移动到其中一个角落吗？

这是我的代码：

public class OpenGLRenderer implements Renderer {

private TexturedSquare element;
private float angle; 

public OpenGLRenderer(Context context) {
    // Initialize things
    int[] bilder = {R.drawable.first};
    element = new TexturedSquare(context, 1f, 1, bilder);
    angle = 0.5f;
}

public void onSurfaceCreated(GL10 gl, EGLConfig config) {

    // Set the background color to black ( rgba )
    gl.glClearColor(1f, 1f, 1f, 1f);
    // Enable Smooth Shading, default not really needed
    gl.glShadeModel(GL10.GL_SMOOTH);// OpenGL docs
    // Depth buffer setup.
    gl.glClearDepthf(1.0f);
    // Enables depth testing.
    gl.glEnable(GL10.GL_DEPTH_TEST);
    // The type of depth testing to do.
    gl.glDepthFunc(GL10.GL_LEQUAL);
    // Really nice perspective calculations.
    gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT,
                      GL10.GL_NICEST);
    // NEW
    element.loadTexture(gl);             // Load images into textures (NEW)
    gl.glEnable(GL10.GL_TEXTURE_2D);
}


public void onDrawFrame(GL10 gl) {

    // Clears the screen and depth buffer.
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    // Replace the current matrix with the identity matrix
    gl.glLoadIdentity();
    // Translates 4 units into the screen.
    gl.glTranslatef(0f, 0f, -4f);
    // What is to be drawn on the screen
    //gl.glRotatef(-angle*20f, 0f, 0f, 1f); // Rotate the element around 3 axes
    //gl.glRotatef(angle, 0f, 1f, 0f);
    //gl.glRotatef(angle, 0f, 0f, 1f);
    element.draw(gl);
    angle++;
}


public void onSurfaceChanged(GL10 gl, int width, int height) {

    // Sets the current view port to the new size.
    gl.glViewport(0, 0, width, height);
    // Select the projection matrix
    gl.glMatrixMode(GL10.GL_PROJECTION);
    // Reset the projection matrix
    gl.glLoadIdentity();// OpenGL docs.
    // Calculate the aspect ratio of the window
    GLU.gluPerspective(gl, 45.0f,
                               (float) width / (float) height,
                               0.1f, 100.0f);
    // Select the modelview matrix
    gl.glMatrixMode(GL10.GL_MODELVIEW);
    // Reset the modelview matrix
    gl.glLoadIdentity();
}
}

这是square class使用的draw方法：

public void draw(GL10 gl) {
  gl.glFrontFace(GL10.GL_CCW);

  gl.glFrontFace(GL10.GL_CCW); // OpenGL docs
    // Enable face culling.
  gl.glEnable(GL10.GL_CULL_FACE); // OpenGL docs
    // What faces to remove with the face culling.
  gl.glCullFace(GL10.GL_BACK); // OpenGL docs

  gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
  gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
  gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
  gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, texBuffer);

  gl.glPushMatrix();
  gl.glTranslatef(0f, 0f, cubeHalfSize);
  gl.glBindTexture(GL10.GL_TEXTURE_2D, textureIDs[0]);
  gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
  gl.glPopMatrix();

  gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
  gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}

任何帮助？

Answer 1

请看gl.glTranslatef（0f，0f，cubeHalfSize）;

如果cubeHalfSize为正值，则不会显示多维数据集。

你的OpenGLRenderer类中已经有了一个“glTranslatef”，所以尝试在你的方形类中注释掉“glTranslatef”：

  gl.glPushMatrix();
  gl.glTranslatef(0f, 0f, cubeHalfSize);
  gl.glBindTexture(GL10.GL_TEXTURE_2D, textureIDs[0]);
 // gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
  gl.glPopMatrix();

Android OpenGL在屏幕的一角显示对象

1 个答案: