gsd_label.c

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/*!
   \file lib/ogsf/gsd_label.c
 
   \brief OGSF library - label management (lower level functions)
 
   GRASS OpenGL gsurf OGSF Library
 
   (C) 1999-2008 by the GRASS Development Team
 
   This program is free software under the
   GNU General Public License (>=v2).
   Read the file COPYING that comes with GRASS
   for details.
 
   \author Bill Brown USACERL (1991-1992)
   \author Doxygenized by Martin Landa <landa.martin gmail.com> (May 2008)
 */
 
#include <grass/gis.h>
#include <grass/glocale.h>
#include <grass/ogsf.h>
 
#include "rgbpack.h"
 
#define MAX_LIST 20
 
static int first = 0;
GLuint label_base;
GLuint label_id;
 
/*!
   \brief Put label
 
   \todo Allocate label dynamically
 
   \param fontbase fontbase settings
   \param size font size
   \param color font color
   \param pt
 */
void gs_put_label(const char *text, GLuint fontbase, int size,
                  unsigned long color, int *pt)
{
    int txt_width;
    GLint tmp[4];
    float labpt[2];
    int t, l, b, r;
 
    if (!first) {
        /* initialize display list */
        label_base = glGenLists(MAX_LIST);
        glListBase(label_base);
        label_id = label_base;
        first = 1;
    }
 
    if (label_id > (label_base + MAX_LIST)) {
        G_warning(_("Max. number of labels reached!"));
        return;
    }
 
    glNewList(label_id, GL_COMPILE_AND_EXECUTE);
    txt_width = gsd_get_txtwidth(text, size);
 
    /* adjust to center text string */
    labpt[X] = (float)(pt[X] - txt_width / 2.);
    labpt[Y] = (float)pt[Y];
 
    glGetIntegerv(GL_VIEWPORT, tmp);
    l = tmp[0];
    r = tmp[0] + tmp[2];
    b = tmp[1];
    t = tmp[1] + tmp[3];
 
    gsd_bgn_legend_viewport(l, b, r, t);
 
    /* Set text color */
    gsd_color_func(color);
 
    do_label_display(fontbase, labpt, text);
 
    gsd_end_legend_viewport();
 
    glEndList();
 
    label_id++;
 
    return;
}
 
/*!
   \brief Remove current label
 */
void gsd_remove_curr(void)
{
    if (label_id) {
        glDeleteLists(label_id - 1, 1);
        label_id--;
    }
 
    return;
}
 
/*!
   \brief Remove all labels from display list
 */
void gsd_remove_all(void)
{
    glDeleteLists(label_base, MAX_LIST);
    label_id = label_base;
 
    return;
}
 
/*!
   \brief Call display list and draw defined labels -- called from gsd_prim
   (gsd_call_lists)
 */
void gsd_call_label(void)
{
    int i;
 
    for (i = 0; i < MAX_LIST; i++) {
        glCallList(i + label_base);
        glFlush();
    }
    return;
}