这是来自NeHe的端口的实际代码，但它没有绘制任何东西。为什么??
我的主要活动课程：
import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
/**
* Our OpenGL program's main activity
*/
public class Main extends Activity {
private GLSurfaceView glView; // Use GLSurfaceView
// Call back when the activity is started, to initialize the view
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
glView = new GLSurfaceView(this); // Allocate a GLSurfaceView
glView.setEGLContextClientVersion(1);
glView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
glView.setRenderer(new mainRenderer(this)); // Use a custom renderer
this.setContentView(glView); // This activity sets to GLSurfaceView
}
// Call back when the activity is going into the background
@Override
protected void onPause() {
super.onPause();
glView.onPause();
}
// Call back after onPause()
@Override
protected void onResume() {
super.onResume();
glView.onResume();
}
}
我的渲染器类：
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.content.Context;
import android.opengl.GLSurfaceView;
import android.opengl.GLU;
/**
* OpenGL Custom renderer used with GLSurfaceView
*/
public class mainRenderer implements GLSurfaceView.Renderer {
Context context; // Application's context
Patrat quad;
// Constructor with global application context
public mainRenderer(Context context) {
this.context = context;
quad = new Patrat();
}
// Call back when the surface is first created or re-created
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); // Set color's clear-value to black
gl.glClearDepthf(1.0f); // Set depth's clear-value to farthest
gl.glEnable(GL10.GL_DEPTH_TEST); // Enables depth-buffer for hidden surface removal
gl.glDepthFunc(GL10.GL_LEQUAL); // The type of depth testing to do
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); // nice perspective view
gl.glShadeModel(GL10.GL_SMOOTH); // Enable smooth shading of color
gl.glDisable(GL10.GL_DITHER); // Disable dithering for better performance
// You OpenGL|ES initialization code here
// ......
}
// Call back after onSurfaceCreated() or whenever the window's size changes
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
if (height == 0) height = 1; // To prevent divide by zero
float aspect = (float)width / height;
// Set the viewport (display area) to cover the entire window
gl.glViewport(0, 0, width, height);
// Setup perspective projection, with aspect ratio matches viewport
gl.glMatrixMode(GL10.GL_PROJECTION); // Select projection matrix
gl.glLoadIdentity(); // Reset projection matrix
// Use perspective projection
GLU.gluPerspective(gl, 45, aspect, 0.1f, 100.f);
gl.glMatrixMode(GL10.GL_MODELVIEW); // Select model-view matrix
gl.glLoadIdentity(); // Reset
// You OpenGL|ES display re-sizing code here
// ......
}
// Call back to draw the current frame.
@Override
public void onDrawFrame(GL10 gl) {
// Clear color and depth buffers using clear-value set earlier
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
// You OpenGL|ES rendering code here
// ......
gl.glLoadIdentity();
quad.draw(gl);
}
}
我的方形课程：
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import javax.microedition.khronos.opengles.GL10;
/*
* A square drawn in 2 triangles (using TRIANGLE_STRIP).
*/
public class Patrat {
private FloatBuffer vertexBuffer; // Buffer for vertex-array
private float[] vertices = { // Vertices for the square
-1.0f, -1.0f, 0.0f, // 0. left-bottom
1.0f, -1.0f, 0.0f, // 1. right-bottom
-1.0f, 1.0f, 0.0f, // 2. left-top
1.0f, 1.0f, 0.0f // 3. right-top
};
// Constructor - Setup the vertex buffer
public Patrat() {
// Setup vertex array buffer. Vertices in float. A float has 4 bytes
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
vbb.order(ByteOrder.nativeOrder()); // Use native byte order
vertexBuffer = vbb.asFloatBuffer(); // Convert from byte to float
vertexBuffer.put(vertices); // Copy data into buffer
vertexBuffer.position(0); // Rewind
}
// Render the shape
public void draw(GL10 gl) {
// Enable vertex-array and define its buffer
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
// Draw the primitives from the vertex-array directly
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
}
}
有任何解决方案吗？我不能忽视为什么这不起作用......
答案 0 :(得分：1)
第一次关闭更改vertices设置了10％：
private float[] vertices = { // Vertices for the square
-0.1f, -0.1f, 0.0f, // 0. left-bottom
0.1f, -0.1f, 0.0f, // 1. right-bottom
-0.1f, 0.1f, 0.0f, // 2. left-top
0.1f, 0.1f, 0.0f // 3. right-top
};
之后我在onDrawFrame(GL10 gl)发现了问题：
您既没有glTranslatef也没有glScalef
将其更改为：
@Override
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
// Reset the Modelview Matrix
gl.glLoadIdentity();
// Drawing
gl.glTranslatef(0.0f, 0.0f, -1.0f); // move 5 units INTO the screen
// is the same as moving the camera 5 units away
gl.glScalef(0.5f, 0.5f, 0.5f); // scale the triangle to 50%
// otherwise it will be too large
quad.draw(gl);
}