在开发应用程序以通过运动事件使用用户输入动态绘制线和圆时，我喜欢在自定义大小的 SurfaceView Renderer 中提供绘图输出，以便我可以将屏幕的其余部分用于其他目的，如菜单等。我在布局中创建了一个 SurfaceView 并尝试提供输出，但是这条线是从 SurfaceView 的中心绘制的，并且与给定的触摸事件不完全一致。有没有可能我们可以通过 SurfaceView 获得输出，还是我在浪费时间？
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1 回答
1
使用surfaceview中的触摸事件在android中的opengl es 2.0中绘制一条线和圆..
Program for Draw Line using touchEvent. when you touch two times, it will draw one line..
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
Log.v("hari", "action down working");
if (count == 1) {
dx = ev.getX();
dy = ev.getY();
dx = (dx / (getWidth() / 2)) - 1;
dy = 1 - (dy / (getHeight() / 2));
Log.i("hari", "line1:" + dx + "," + dy);
firstX = dx;
firstY = dy;
} else if (count == 2) {
ux = ev.getX();
uy = ev.getY();
ux = (ux / (getWidth() / 2)) - 1;
uy = 1 - (uy / (getHeight() / 2));
Log.i("hari", "line2:" + ux + "," + uy);
secondX = ux;
secondY = uy;
myRenderer.dx = firstX;
myRenderer.dy = firstY;
myRenderer.ux = secondX;
myRenderer.uy = secondY;
requestRender();
count = 0;
}
break;
}
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My Renderer Program :
package com.example.ibus;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView.Renderer;
import android.util.Log;
public class MyRenderer implements Renderer {
MainActivity main;
MyGLsurfaceview myGlsurface;
public volatile boolean myline, mycircle, mydashedline , mysnaptoedge , snapBoolean ;
public volatile double angle,length;
public volatile float dlsx, dlsy, dlex, dley, dlsx1, dlsy1,
dlex1, dley1, dltx, dlty, len;
public volatile double rad, dlrad;
int n, i;
Lines line;
Circle circle;
Snap snapedge;
// Declare as volatile because we are updating it from another thread
public volatile float dx, dy, ux, uy, Dist, centerX,centerY,firstX,firstY,
secondX,secondY, sex, sey;
private float sx, sy, fx, fy, tx, ty;
private double radian, rradian;
public MyRenderer(MainActivity mainActivity, MyGLsurfaceview myGlsurfaceView) {
Log.i("JO", "MyRenderer");
main = mainActivity;
myGlsurface = myGlsurfaceView;
}
@Override
public void onDrawFrame(GL10 gl) {
Log.i("JO", "onDrawFrame");
// line.draw(x,y);
Log.i("JO", "onDrawFrame:DX:"+dx+",DY:"+dy+",UX:"+ux+",UY:"+uy);
// Draw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
//GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
if(myline){
line.draw(dx,dy,ux,uy);
}
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
Log.i("JO", "onSurfaceChanged");
// Adjust the viewport based on geometry changes,
// such as screen rotation
GLES20.glViewport(0, 0, width, height);
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
Log.i("JO", "onSurfaceCreated");
// Set the background frame color
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
line = new Lines();
}
public static int loadShader(int type, String shaderCode) {
// create a vertex shader type (GLES20.GL_VERTEX_SHADER)
// or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
// add the source code to the shader and compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
class Lines {
final String vertexShaderCode = "attribute vec4 vPosition;"
+ "void main() {" + " gl_Position = vPosition;" + "}";
final String fragmentShaderCode = "precision mediump float;"
+ "uniform vec4 vColor;" + "void main() {"
+ " gl_FragColor = vColor;" + "}";
final FloatBuffer vertexBuffer;
final int mProgram;
int mPositionHandle;
int mColorHandle;
// number of coordinates per vertex in this array
final int COORDS_PER_VERTEX = 3;
float lineCoords[] = new float[6];
final int vertexCount = lineCoords.length / COORDS_PER_VERTEX;
final int vertexStride = COORDS_PER_VERTEX * 4; // bytes per vertex
// Set color with red, green, blue and alpha (opacity) values
float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
public Lines() {
// initialize vertex byte buffer for shape coordinates
ByteBuffer bb = ByteBuffer.allocateDirect(
// (number of coordinate values * 4 bytes per float)
lineCoords.length * 4);
// use the device hardware's native byte order
bb.order(ByteOrder.nativeOrder());
// create a floating point buffer from the ByteBuffer
vertexBuffer = bb.asFloatBuffer();
// prepare shaders and OpenGL program
int vertexShader = MyRenderer.loadShader(GLES20.GL_VERTEX_SHADER,
vertexShaderCode);
int fragmentShader = MyRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER,
fragmentShaderCode);
mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader
// to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment
// shader to program
GLES20.glLinkProgram(mProgram); // create OpenGL program executables
}
public void draw(float dX,float dY,float uX,float uY) {
lineCoords[0] = dX;
lineCoords[1] = dY;
lineCoords[2] = 0.0f;
lineCoords[3] = uX;
lineCoords[4] = uY;
lineCoords[5] = 0.0f;
vertexBuffer.put(lineCoords);
vertexBuffer.position(0);
// Add program to OpenGL environment
GLES20.glUseProgram(mProgram);
// get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
// Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,
GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
// get handle to fragment shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
// Set color for drawing the triangle
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
// Draw the triangle
GLES20.glDrawArrays(GLES20.GL_LINES, 0, vertexCount);
// Disable vertex array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
}
}
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于 2013-05-13T10:30:07.710 回答