使用OpenGLEs for Android绘制Pixel

Question

How can I draw a pixel(2D view)for Android using OpenGlEs?

It is simple when we use for drawing

draw(Canvas canvas)
{
   ...
} 

So using it we draw

canvas.drawPoint(i, j, paint);

But in OpenGlEs I still haven't got any function like it.

Please reply Thank in Advance

Answer 1

    GLES20Renderer.programLight = GLES20.glCreateProgram();
    int vertexShaderLight       = GLES20Renderer.loadShader(GLES20.GL_VERTEX_SHADER, GLES20Renderer.vertexShaderCodeLight);
    int fragmentShaderLight     = GLES20Renderer.loadShader(GLES20.GL_FRAGMENT_SHADER, GLES20Renderer.fragmentShaderCodeLight);
    GLES20.glAttachShader(GLES20Renderer.programLight, vertexShaderLight);
    GLES20.glAttachShader(GLES20Renderer.programLight, fragmentShaderLight);
    GLES20.glLinkProgram(GLES20Renderer.programLight);
    uPLocationLight             = GLES20.glGetUniformLocation(GLES20Renderer.programLight, "uP");
    uVPositionLocationLight     = GLES20.glGetUniformLocation(GLES20Renderer.programLight, "uVPosition");

    GLES20.glUseProgram(GLES20Renderer.programLight);
    GLES20.glUniform4f(uVPositionLocationLight, LightPosInEyeSpace[0], LightPosInEyeSpace[1], LightPosInEyeSpace[2], LightPosInEyeSpace[3]);
    GLES20.glUniformMatrix4fv(uPLocationLight, 1, false, ProjectionMatrix, 0);
    GLES20.glDrawArrays(GLES20.GL_POINTS, 0, 1);


private static final String vertexShaderCodeLight = 
        "uniform vec4 uVPosition;                   \n"
    +   "uniform mat4 uP;                           \n"
    +   "void main(){                               \n"
    +   " gl_PointSize = 15.0;                      \n"
    +   " gl_Position = uP * uVPosition;            \n"
    +   "}                                          \n";
private static final String fragmentShaderCodeLight = 
        "#ifdef GL_FRAGMENT_PRECISION_HIGH          \n"
    +   "precision highp float;                     \n"
    +   "#else                                      \n"
    +   "precision mediump float;                   \n"
    +   "#endif                                     \n"
    +   "void main(){                               \n"
    +   " gl_FragColor = vec4(1.0,1.0,1.0,1.0);     \n"
    +   "}                                          \n";

Answer 2

glDrawElements(GL_POINTS, 0, num_points, point_array); You can also use glDrawArrays if you use glVertexPointer first.

Use glPointParameter, glPointSize, and glColor to modify the appearance of the points. Using glPointSizePointer lets you specify an array of point sizes, which is handy for particle effects.