4.5.3 Bitmap in memory

These functions return the created picture (bitmap), its width and height. You may display it by yourself in any graphical library (see also, Widget classes) or save in file (see also, Export to file).

Method on mglGraph: const unsigned char * GetRGB ()

Method on mglGraph: void GetRGB (char *buf, int size)

Method on mglGraph: void GetBGRN (char *buf, int size)

C function: const unsigned char * mgl_get_rgb (HMGL gr)

Gets RGB bitmap of the current state of the image. Format of each element of bits is: {red, green, blue}. Number of elements is Width*Height. Position of element {i,j} is [3*i + 3*Width*j] (or is [4*i + 4*Width*j] for GetBGRN()). You have to provide the proper size of the buffer, buf, i.e. the code for Python should look like

from mathgl import *
gr = mglGraph();
bits='\t';
bits=bits.expandtabs(4*gr.GetWidth()*gr.GetHeight());
gr.GetBGRN(bits, len(bits));

Method on mglGraph: const unsigned char * GetRGBA ()

Method on mglGraph: void GetRGBA (char *buf, int size)

C function: const unsigned char * mgl_get_rgba (HMGL gr)

Gets RGBA bitmap of the current state of the image. Format of each element of bits is: {red, green, blue, alpha}. Number of elements is Width*Height. Position of element {i,j} is [4*i + 4*Width*j].

Method on mglGraph: int GetWidth ()

Method on mglGraph: int GetHeight ()

C function: int mgl_get_width (HMGL gr)

C function: int mgl_get_height (HMGL gr)

Gets width and height of the image.

Method on mglGraph: mglPoint CalcXYZ (int xs, int ys)

C function: void mgl_calc_xyz (HMGL gr, int xs, int ys, mreal *x, mreal *y, mreal *z)

Calculate 3D coordinate {x,y,z} for screen point {xs,ys}. At this moment it ignore perspective and transformation formulas (curvilinear coordinates). The calculation are done for the last used InPlot (see Subplots and rotation).

Method on mglGraph: mglPoint CalcScr (mglPoint p)

C function: void mgl_calc_scr (HMGL gr, mreal x, mreal y, mreal z, int *xs, int *ys)

Calculate screen point {xs,ys} for 3D coordinate {x,y,z}. The calculation are done for the last used InPlot (see Subplots and rotation).

Method on mglGraph: void SetObjId (int id)

C function: void mgl_set_obj_id (HMGL gr, int id)

Set the numeric id for object or subplot/inplot.

Method on mglGraph: int GetObjId (int xs, int ys)

C function: int mgl_get_obj_id (HMGL gr, int xs, int ys)

Get the numeric id for most upper object at pixel {xs, ys} of the picture.

Method on mglGraph: int GetSplId (int xs, int ys)

C function: int mgl_get_spl_id (HMGL gr, int xs, int ys)

Get the numeric id for most subplot/inplot at pixel {xs, ys} of the picture.

Method on mglGraph: void Highlight (int id)

C function: void mgl_highlight (HMGL gr, int id)

Highlight the object with given id.

Method on mglGraph: long IsActive (int xs, int ys, int d=1)

C function: long mgl_is_active (HMGL gr, int xs, int ys, int d)

Checks if point {xs, ys} is close to one of active point (i.e. mglBase::Act) with accuracy d and return its index or -1 if not found. Active points are special points which characterize primitives (like edges and so on). This function for advanced users only.

Method on mglGraph: long SetDrawReg (int nx=1, int ny=1, int m=0)

C function: long mgl_set_draw_reg (HMGL gr, int nx, int ny, int m)

Limits drawing region by rectangular area of m-th cell of matrix with sizes nx*ny (like in subplot). This function can be used to update only small region of the image for purposes of higher speed. This function for advanced users only.

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