C++ 获取当前 ModelView 矩阵

Obtaining current ModelView matrix

提问by arul

In OpenGL, how do I read the current x/y translation in the modelview matrix? I know that you have to load the current matrix into an array and read the floats from there, but I don't know precisely how to do it.

在 OpenGL 中，如何读取模型视图矩阵中的当前 x/y 平移？我知道你必须将当前矩阵加载到一个数组中并从那里读取浮点数，但我不知道如何做到这一点。

回答by arul

In order to retrieve the current modelview matrix you have to call the glGetFloatvfunction with GL_MODELVIEW_MATRIXparameter.

为了检索当前的模型视图矩阵，您必须使用参数调用glGetFloatv函数GL_MODELVIEW_MATRIX。

GLfloat matrix[16]; 
glGetFloatv (GL_MODELVIEW_MATRIX, matrix); 

From the documentation:

从文档：

GL_MODELVIEW_MATRIX

params returns sixteen values: the modelview matrix on the top of the modelview matrix stack. Initially this matrix is the identity matrix.

GL_MODELVIEW_MATRIX

params 返回十六个值：模型视图矩阵堆栈顶部的模型视图矩阵。最初这个矩阵是单位矩阵。

回答by Brian Gianforcaro

Use glGlet

使用glGlet

GLfloat matrixf[16];
glGetFloatv(GL_MODELVIEW_MATRIX, matrixf);

GLdouble matrixd[16];
glGetDoublev(GL_MODELVIEW_MATRIX, matrixd);

GLint matrixi[16];
glGetIntegerv(GL_MODELVIEW_MATRIX, matrixi);