openGL 高程配色绘制点云（csGL）

• 配色函数

private void setColor(double Z)
        {
            float r, g, b;
            if (Z > colorParam1)
            {
                r = (float)((Z - colorParam1) / colorParam2);
                b = 0;
            }
            else
            {
                r = 0;
                b = (float)((colorParam1 - Z) / colorParam2);
            }
            g = 1 - (float)((Math.Abs(colorParam1 - Z)) / colorParam2);
            GL.glColor3f(r, g, b);
            return;
        }

• 画点函数

private void draw_Points(float[] X, float[] Y, float[] Z)
        {
            GL.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
            GL.glClearDepth(1.0);
            GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

            GL.glMatrixMode(GL.GL_PROJECTION);
            GL.glLoadIdentity();
            GL.gluPerspective(90.0, 1.0, 1.0, 6 * eyez);  // 投影矩阵（ y 45度，纵横比1：1，near截平面1，far截平面10000.）

            //GL.glOrtho(vertx[0].Min(), vertx[0].Max(), vertx[1].Min(), vertx[1].Max(), 1.0f, 6 * eyez);//dtmZ.Min(), dtmZ.Max());

            GL.glMatrixMode(GL.GL_MODELVIEW);    // 模型矩阵
            GL.glLoadIdentity();

            //GL.glDrawBuffer(GL.GL_BACK);                                   // Specifies up to four color buffers to be drawn into with the following acceptable symbolic constants.

            GL.glPushMatrix();

            GL.gluLookAt(eyex, eyey, eyez, centerx, centery, 0.0f, 0.0f, 1.0f, 0.0f); //defines a viewing transformation
            GL.glRotatef(roll_x, 1.0f, 0.0f, 0.0f);//    
            GL.glRotatef(yaw_z, 0.0f, 0.0f, 1.0f);//
            GL.glRotatef(pitch_y, 0.0f, 1.0f, 0.0f);//
            GL.glScalef(m_Scalex, m_Scaley, m_Scalez);//缩放


            for (int i = 0; i < row; i += LOD_scale)
            {

                GL.glBegin(GL.GL_POINTS);

                for (int j = 0; j < column; j += LOD_scale)
                {
                    if (Z[i * column + j] == -frm3d.Zc)
                        continue;
                    setColor(Z[i * column + j]);

                    GL.glVertex3f(X[i * column + j], Y[i * column + j], Z[i * column + j]);

                }
                GL.glEnd();
                GL.glFlush();
            }
            /*
             * glFlush:将GL命令队列中的命令发送给显卡并清空命令队列，发送完立即返回；
             * glFinish:将GL命令队列中的命令发送给显卡并清空命令队列，显卡完成这些命令（也就是画完了）后返回。
             */
            
            GL.glPopMatrix();
        }