app/grid.c

   1 /* Dia -- an diagram creation/manipulation program
   2  * Copyright (C) 1998 Alexander Larsson
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 #include <config.h>
  21 #endif
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <math.h>
  26 #include <glib.h>
  27
  28 #include "intl.h"
  29 #include "grid.h"
  30 #include "preferences.h"
  31
  32 /** Calculate the width (in cm) of the gap between grid lines in dynamic
  33  * grid mode.
  34  */
  35 static real
  36 calculate_dynamic_grid(DDisplay *ddisp, real *width_x, real *width_y)
  37 {
  38   real zoom = ddisplay_untransform_length(ddisp, 1.0);
  39   /* Twiddle zoom to make change-over appropriate */
  40   zoom *= 5;
  41   return pow(10, ceil(log10(zoom)));
  42 }
  43
  44 static void
  45 grid_draw_horizontal_lines(DDisplay *ddisp, Rectangle *update, real length)
  46 {
  47   int x, y;
  48   real pos;
  49   int height, width;
  50   guint major_lines = ddisp->diagram->data->grid.major_lines;
  51   DiaRenderer *renderer = ddisp->renderer;
  52   DiaInteractiveRendererInterface *irenderer;
  53   int major_count;
  54
  55   irenderer = DIA_GET_INTERACTIVE_RENDERER_INTERFACE (renderer);
  56
  57   pos = ceil( update->top / length ) * length;
  58   ddisplay_transform_coords(ddisp, update->left, pos, &x, &y);
  59   ddisplay_transform_coords(ddisp, update->right, update->bottom, &width, &height);
  60
  61   if (major_lines) {
  62     major_count = pos/length;
  63     major_count %= major_lines;
  64   }
  65
  66   while (y < height) {
  67     if (major_lines) {
  68       if (major_count == 0)
  69         DIA_RENDERER_GET_CLASS(renderer)->set_linestyle(renderer, LINESTYLE_SOLID);
  70       else
  71         DIA_RENDERER_GET_CLASS(renderer)->set_linestyle(renderer, LINESTYLE_DOTTED);
  72       major_count = (major_count+1)%major_lines;
  73     }
  74     irenderer->draw_pixel_line(renderer, x, y, width, y,
  75                                &ddisp->diagram->data->grid.colour);
  76     pos += length;
  77     ddisplay_transform_coords(ddisp, update->left, pos, &x, &y);
  78   }
  79 }
  80
  81 static void
  82 grid_draw_vertical_lines(DDisplay *ddisp, Rectangle *update, real length)
  83 {
  84   int x = 0, y = 0;
  85   real pos;
  86   int height, width;
  87   guint major_lines = ddisp->diagram->data->grid.major_lines;
  88   DiaRenderer *renderer = ddisp->renderer;
  89   DiaInteractiveRendererInterface *irenderer;
  90   int major_count;
  91
  92   irenderer = DIA_GET_INTERACTIVE_RENDERER_INTERFACE (renderer);
  93
  94   pos = ceil( update->left / length ) * length;
  95   ddisplay_transform_coords(ddisp, update->right, update->bottom, &width, &height);
  96
  97   if (major_lines) {
  98     major_count = pos/length;
  99     major_count %= major_lines;
 100   }
 101
 102   while (x < width) {
 103     ddisplay_transform_coords(ddisp, pos, update->top, &x, &y);
 104     if (major_lines) {
 105       if (major_count == 0)
 106         DIA_RENDERER_GET_CLASS(renderer)->set_linestyle(renderer, LINESTYLE_SOLID);
 107       else
 108         DIA_RENDERER_GET_CLASS(renderer)->set_linestyle(renderer, LINESTYLE_DOTTED);
 109       major_count = (major_count+1)%major_lines;
 110     }
 111     irenderer->draw_pixel_line(renderer, x, y, x, height,
 112                                &ddisp->diagram->data->grid.colour);
 113     pos += length;
 114   }
 115 }
 116
 117 void
 118 grid_draw(DDisplay *ddisp, Rectangle *update)
 119 {
 120   Grid *grid = &ddisp->grid;
 121   DiaRenderer *renderer = ddisp->renderer;
 122   int major_lines;
 123
 124   if (grid->visible) {
 125     int width = dia_renderer_get_width_pixels(ddisp->renderer);
 126     int height = dia_renderer_get_height_pixels(ddisp->renderer);
 127     /* distance between visible grid lines */
 128     real width_x = ddisp->diagram->data->grid.width_x;
 129     real width_y = ddisp->diagram->data->grid.width_y;
 130     if (ddisp->diagram->data->grid.dynamic) {
 131       width_x = width_y = calculate_dynamic_grid(ddisp, &width_x, &width_y);
 132     } else {
 133       width_x = ddisp->diagram->data->grid.width_x *
 134         ddisp->diagram->data->grid.visible_x;
 135       width_y = ddisp->diagram->data->grid.width_y *
 136         ddisp->diagram->data->grid.visible_y;
 137     }
 138
 139     DIA_RENDERER_GET_CLASS(renderer)->set_linewidth(renderer, 0.0);
 140     DIA_RENDERER_GET_CLASS(renderer)->set_dashlength(renderer,
 141                                                      ddisplay_untransform_length(ddisp, 31));
 142
 143     if (ddisplay_transform_length(ddisp, width_y) >= 2.0 &&
 144         ddisplay_transform_length(ddisp, width_x) >= 2.0) {
 145       /* Vertical lines: */
 146       grid_draw_vertical_lines(ddisp, update, width_x);
 147       /* Horizontal lines: */
 148       grid_draw_horizontal_lines(ddisp, update, width_y);
 149     }
 150   }
 151 }
 152
 153 void
 154 pagebreak_draw(DDisplay *ddisp, Rectangle *update)
 155 {
 156   DiaRenderer *renderer = ddisp->renderer;
 157   DiaInteractiveRendererInterface *irenderer;
 158
 159   int width = dia_renderer_get_width_pixels(ddisp->renderer);
 160   int height = dia_renderer_get_height_pixels(ddisp->renderer);
 161
 162   irenderer = DIA_GET_INTERACTIVE_RENDERER_INTERFACE (renderer);
 163   if (prefs.pagebreak.visible) {
 164     Diagram *dia = ddisp->diagram;
 165     real origx = 0, origy = 0, pos;
 166     real pwidth = dia->data->paper.width;
 167     real pheight = dia->data->paper.height;
 168     int x,y;
 169
 170     DIA_RENDERER_GET_CLASS(renderer)->set_linewidth(renderer, 0.0);
 171     DIA_RENDERER_GET_CLASS(renderer)->set_dashlength(renderer,
 172                                     ddisplay_untransform_length(ddisp, 31));
 173     if (prefs.pagebreak.solid)
 174       DIA_RENDERER_GET_CLASS(renderer)->set_linestyle(renderer, LINESTYLE_SOLID);
 175     else
 176       DIA_RENDERER_GET_CLASS(renderer)->set_linestyle(renderer, LINESTYLE_DOTTED);
 177
 178     if (dia->data->paper.fitto) {
 179       origx = dia->data->extents.left;
 180       origy = dia->data->extents.top;
 181     }
 182
 183     /* vertical lines ... */
 184     pos = origx + ceil((update->left - origx) / pwidth) * pwidth;
 185     while (pos <= update->right) {
 186       ddisplay_transform_coords(ddisp, pos,0,&x,&y);
 187       irenderer->draw_pixel_line(renderer,
 188                                  x, 0, x, height,
 189                                  &dia->data->pagebreak_color);
 190       pos += pwidth;
 191     }
 192     /* Horizontal lines: */
 193     pos = origy + ceil((update->top - origy) / pheight) * pheight;
 194     while (pos <= update->bottom) {
 195       ddisplay_transform_coords(ddisp, 0,pos,&x,&y);
 196       irenderer->draw_pixel_line(renderer,
 197                                  0, y, width, y,
 198                                  &dia->data->pagebreak_color);
 199       pos += pheight;
 200     }
 201   }
 202 }
 203
 204 void
 205 snap_to_grid(DDisplay *ddisp, coord *x, coord *y)
 206 {
 207   if (ddisp->grid.snap) {
 208     real width_x = ddisp->diagram->data->grid.width_x;
 209     real width_y = ddisp->diagram->data->grid.width_y;
 210     if (prefs.grid.dynamic) {
 211       calculate_dynamic_grid(ddisp, &width_x, &width_y);
 212     }
 213     *x = ROUND((*x) / width_x) * width_x;
 214     *y = ROUND((*y) / width_y) * width_y;
 215   }
 216 }