在android open 2.0中绘制线条
嗨,我是android OpenGL的新手。我尝试在OpenGles 2.0中创建一些2d对象。现在我试着在android Open2.0中划一条线。我的代码看起来像在android open 2.0中绘制线条,android,opengl-es-2.0,line,Android,Opengl Es 2.0,Line,嗨,我是android OpenGL的新手。我尝试在OpenGles 2.0中创建一些2d对象。现在我试着在android Open2.0中划一条线。我的代码看起来像 public class UserLine { private final String vertexShaderCode = "uniform mat4 uMVPMatrix;" + "attribute vec4 vPosition;" + "v
public class UserLine
{
private final String vertexShaderCode =
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"void main() {" +
" gl_Position = uMVPMatrix * vPosition;" +
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
"void main() {" +
" gl_FragColor = vColor;" +
"}";
private final FloatBuffer vertexBuffer;
private final ShortBuffer drawListBuffer;
private final int mProgram;
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
static final int COORDS_PER_VERTEX = 3;
private final int vertexStride = COORDS_PER_VERTEX * 4;
private float[] pathCords =
{
0.00f, 0.0f, 0.0f,
0.5f, 0.3f, 0.0f
};
private short[] pathDrawOrder = {0,1}
private float[] color = {1.0f, 0.0f, 0.0f, 1.0f};
public UserLine()
{
ByteBuffer bb = ByteBuffer.allocateDirect(pathCords.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(pathCords);
vertexBuffer.position(0);
ByteBuffer dlb = ByteBuffer.allocateDirect(pathDrawOrder.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(pathDrawOrder);
drawListBuffer.position(0);
int vertexShader = MyGLRenderer.loadShader(GLES20.GL_VERTEX_SHADER,vertexShaderCode);
int fragmentShader = MyGLRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER,fragmentShaderCode);
mProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(mProgram, vertexShader);
GLES20.glAttachShader(mProgram, fragmentShader);
GLES20.glLinkProgram(mProgram);
}
public void draw(float[] mvpMatrix) {
GLES20.glUseProgram(mProgram);
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,GLES20.GL_FLOAT, false,
vertexStride, vertexBuffer);
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
GLES20.glDrawElements(GLES20.GL_LINES, color.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glDisable(mColorHandle);
}
}
这是我的问题,根据这段代码,它必须画一条线,但沿着这条线,它也画了一条额外的线,这不是预期的行为
我是做错了什么,还是这是我的默认行为。我需要帮助。谢谢。我认为问题在于:
GLES20.glDrawElements(GLES20.GL_LINES, color.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
第二个参数是计数,我不明白为什么要将它设置为颜色的长度。这只是传递到着色器中的线的颜色,因此长度始终为4:
private float[] color = {1.0f, 0.0f, 0.0f, 1.0f};
正如pathDrawOrder中指定的那样,您正在绘制一条带有2个点的直线,因此我认为使用该点的长度是您需要的:
GLES20.glDrawElements(GLES20.GL_LINES, pathDrawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
我认为问题在于:
GLES20.glDrawElements(GLES20.GL_LINES, color.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
第二个参数是计数,我不明白为什么要将它设置为颜色的长度。这只是传递到着色器中的线的颜色,因此长度始终为4:
private float[] color = {1.0f, 0.0f, 0.0f, 1.0f};
正如pathDrawOrder中指定的那样,您正在绘制一条带有2个点的直线,因此我认为使用该点的长度是您需要的:
GLES20.glDrawElements(GLES20.GL_LINES, pathDrawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
我认为问题在于:
GLES20.glDrawElements(GLES20.GL_LINES, color.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
第二个参数是计数,我不明白为什么要将它设置为颜色的长度。这只是传递到着色器中的线的颜色,因此长度始终为4:
private float[] color = {1.0f, 0.0f, 0.0f, 1.0f};
正如pathDrawOrder中指定的那样,您正在绘制一条带有2个点的直线,因此我认为使用该点的长度是您需要的:
GLES20.glDrawElements(GLES20.GL_LINES, pathDrawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
我认为问题在于:
GLES20.glDrawElements(GLES20.GL_LINES, color.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
第二个参数是计数,我不明白为什么要将它设置为颜色的长度。这只是传递到着色器中的线的颜色,因此长度始终为4:
private float[] color = {1.0f, 0.0f, 0.0f, 1.0f};
正如pathDrawOrder中指定的那样,您正在绘制一条带有2个点的直线,因此我认为使用该点的长度是您需要的:
GLES20.glDrawElements(GLES20.GL_LINES, pathDrawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
谢谢你点击我的错误。谢谢。谢谢你点击我的错误。谢谢。谢谢你点击我的错误。谢谢。谢谢你点击我的错误。非常感谢。