比较急搞了几天了，OPENGL实现鼠标托动控制物体旋转的问题。

zhaowei303 2014-01-11 05:18:48

类库用的是sharpgl,下边是我用鼠标托动控制旋转的关键代码，在鼠标托动时还是没有实现。在绘图的时主要会用到这个旋转void glRotate{fd}(TYPE angle,TYPE x,TYPE y,TYPE z),比较急请帮忙看一下具体的方法那个地方有问题，或者有人实现了参考一下代码。

double[] lastMatrix = new double[16] // 前一次矩阵，初始化为单位矩阵E
{1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0};
private double theta; // 旋转角度
private double[] axis = new double[3]; // 旋转轴
private double[] lastPos = new double[3], curPos = new double[3]; // 鼠标上次和当前坐标

private int hemishere(int x, int y, int d,double[] v)
{
double z;
// 计算x, y坐标
v[0] = (double)x * 2.0 - (double)d;
v[1] = (double)d - (double)y * 2.0;
// 计算z坐标
z = d * d - v[0] * v[0] - v[1] * v[1];
if (z < 0)
{
return 0;
}
v[2] = Math.Sqrt(z);
// 单位化
v[0] /= (double)d;
v[1] /= (double)d;
v[2] /= (double)d;
return 1;
}

private void openGLControl1_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
double d, dx, dy, dz;
// 计算当前的鼠标单位半球面坐标
if (hemishere(e.X, e.Y, 500, curPos)!=1)
{
return;
}
// 计算移动量的三个方向分量
dx = curPos[0] - lastPos[0];
dy = curPos[1] - lastPos[1];
dz = curPos[2] - lastPos[2];
// 如果有移动
if (dx != 0 || dy != 0 || dz != 0)
{
// 计算移动距离，用来近似移动的球面距离
d = Math.Sqrt(dx * dx + dy * dy + dz * dz);
// 通过移动距离计算移动的角度
theta = d * 180.0;
// 计算移动平面的法向量，即：lastPos × curPos
axis[0] = lastPos[1] * curPos[2] - lastPos[2] * curPos[1];
axis[1] = lastPos[2] * curPos[0] - lastPos[0] * curPos[2];
axis[2] = lastPos[0] * curPos[1] - lastPos[1] * curPos[0];
// 记录当前的鼠标单位半球面坐标
lastPos[0] = curPos[0];
lastPos[1] = curPos[1];
lastPos[2] = curPos[2];
// 重绘窗口
glDraw();
}
}
}

private void openGLControl1_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
hemishere(e.X, e.Y, 500, lastPos);
}
}

private void glDraw()
{
SharpGL.OpenGL gl = this.openGLControl1.OpenGL;
gl.Clear(OpenGL.COLOR_BUFFER_BIT | OpenGL.DEPTH_BUFFER_BIT);
gl.MatrixMode(OpenGL.MODELVIEW); // 设置当前使用模型视图矩阵栈
gl.LoadIdentity(); // Reset The View
gl.Translate(-1.5f, 0.0f, -6.0f); // Move Left And Into The Screen

// 计算新的旋转矩阵，即：M = E · R = R
gl.Rotate(theta, axis[0], axis[1], axis[2]);
//// 左乘上前一次的矩阵，即：M = R · L
gl.MultMatrix(lastMatrix);
//// 保存此次处理结果，即：L = M
gl.GetDouble(OpenGL.MODELVIEW_MATRIX, lastMatrix);
gl.Begin(OpenGL.TRIANGLES); // Start Drawing The Pyramid
gl.Color(1.0f, 0.0f, 0.0f); // Red
gl.Vertex(0.0f, 1.0f, 0.0f); // Top Of Triangle (Front)
gl.Color(0.0f, 1.0f, 0.0f); // Green
gl.Vertex(-1.0f, -1.0f, 1.0f); // Left Of Triangle (Front)
gl.Color(0.0f, 0.0f, 1.0f); // Blue
gl.Vertex(1.0f, -1.0f, 1.0f); // Right Of Triangle (Front)

gl.Color(1.0f, 0.0f, 0.0f); // Red
gl.Vertex(0.0f, 1.0f, 0.0f); // Top Of Triangle (Right)
gl.Color(0.0f, 0.0f, 1.0f); // Blue
gl.Vertex(1.0f, -1.0f, 1.0f); // Left Of Triangle (Right)
gl.Color(0.0f, 1.0f, 0.0f); // Green
gl.Vertex(1.0f, -1.0f, -1.0f); // Right Of Triangle (Right)

gl.Color(1.0f, 0.0f, 0.0f); // Red
gl.Vertex(0.0f, 1.0f, 0.0f); // Top Of Triangle (Back)
gl.Color(0.0f, 1.0f, 0.0f); // Green
gl.Vertex(1.0f, -1.0f, -1.0f); // Left Of Triangle (Back)
gl.Color(0.0f, 0.0f, 1.0f); // Blue
gl.Vertex(-1.0f, -1.0f, -1.0f); // Right Of Triangle (Back)

gl.Color(1.0f, 0.0f, 0.0f); // Red
gl.Vertex(0.0f, 1.0f, 0.0f); // Top Of Triangle (Left)
gl.Color(0.0f, 0.0f, 1.0f); // Blue
gl.Vertex(-1.0f, -1.0f, -1.0f); // Left Of Triangle (Left)
gl.Color(0.0f, 1.0f, 0.0f); // Green
gl.Vertex(-1.0f, -1.0f, 1.0f); // Right Of Triangle (Left)
gl.End();
}

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