1 #define CANVAS_AXONOMGRID_C
3 /*
4 * Copyright (C) 2006-2007 Johan Engelen <johan@shouraizou.nl>
5 */
7 /*
8 * Current limits are: one axis (y-axis) is always vertical. The other two
9 * axes are bound to a certain range of angles. The z-axis always has an angle
10 * smaller than 90 degrees (measured from horizontal, 0 degrees being a line extending
11 * to the right). The x-axis will always have an angle between 0 and 90 degrees.
12 * When I quickly think about it: all possibilities are probably covered this way. Eg.
13 * a z-axis with negative angle can be replaced with an x-axis, etc.
14 */
16 /*
17 * TODO:
18 * THIS FILE AND THE HEADER FILE NEED CLEANING UP. PLEASE DO NOT HESISTATE TO DO SO.
19 * For example: the line drawing code should not be here. There _must_ be a function somewhere else that can provide this functionality...
20 */
22 #include "sp-canvas-util.h"
23 #include "canvas-axonomgrid.h"
24 #include "util/mathfns.h"
25 #include "2geom/geom.h"
26 #include "display-forward.h"
27 #include <libnr/nr-pixops.h>
29 #include "canvas-grid.h"
30 #include "desktop-handles.h"
31 #include "helper/units.h"
32 #include "svg/svg-color.h"
33 #include "xml/node-event-vector.h"
34 #include "sp-object.h"
36 #include "sp-namedview.h"
37 #include "inkscape.h"
38 #include "desktop.h"
40 #include "document.h"
41 #include "prefs-utils.h"
43 #define SAFE_SETPIXEL //undefine this when it is certain that setpixel is never called with invalid params
45 enum Dim3 { X=0, Y, Z };
47 #ifndef M_PI
48 # define M_PI 3.14159265358979323846
49 #endif
51 static double deg_to_rad(double deg) { return deg*M_PI/180.0;}
54 /**
55 \brief This function renders a pixel on a particular buffer.
57 The topleft of the buffer equals
58 ( rect.x0 , rect.y0 ) in screen coordinates
59 ( 0 , 0 ) in setpixel coordinates
60 The bottomright of the buffer equals
61 ( rect.x1 , rect,y1 ) in screen coordinates
62 ( rect.x1 - rect.x0 , rect.y1 - rect.y0 ) in setpixel coordinates
63 */
64 static void
65 sp_caxonomgrid_setpixel (SPCanvasBuf *buf, gint x, gint y, guint32 rgba)
66 {
67 #ifdef SAFE_SETPIXEL
68 if ( (x >= buf->rect.x0) && (x < buf->rect.x1) && (y >= buf->rect.y0) && (y < buf->rect.y1) ) {
69 #endif
70 guint r, g, b, a;
71 r = NR_RGBA32_R (rgba);
72 g = NR_RGBA32_G (rgba);
73 b = NR_RGBA32_B (rgba);
74 a = NR_RGBA32_A (rgba);
75 guchar * p = buf->buf + (y - buf->rect.y0) * buf->buf_rowstride + (x - buf->rect.x0) * 3;
76 p[0] = NR_COMPOSEN11_1111 (r, a, p[0]);
77 p[1] = NR_COMPOSEN11_1111 (g, a, p[1]);
78 p[2] = NR_COMPOSEN11_1111 (b, a, p[2]);
79 #ifdef SAFE_SETPIXEL
80 }
81 #endif
82 }
84 /**
85 \brief This function renders a line on a particular canvas buffer,
86 using Bresenham's line drawing function.
87 http://www.cs.unc.edu/~mcmillan/comp136/Lecture6/Lines.html
88 Coordinates are interpreted as SCREENcoordinates
89 */
90 static void
91 sp_caxonomgrid_drawline (SPCanvasBuf *buf, gint x0, gint y0, gint x1, gint y1, guint32 rgba)
92 {
93 int dy = y1 - y0;
94 int dx = x1 - x0;
95 int stepx, stepy;
97 if (dy < 0) { dy = -dy; stepy = -1; } else { stepy = 1; }
98 if (dx < 0) { dx = -dx; stepx = -1; } else { stepx = 1; }
99 dy <<= 1; // dy is now 2*dy
100 dx <<= 1; // dx is now 2*dx
102 sp_caxonomgrid_setpixel(buf, x0, y0, rgba);
103 if (dx > dy) {
104 int fraction = dy - (dx >> 1); // same as 2*dy - dx
105 while (x0 != x1) {
106 if (fraction >= 0) {
107 y0 += stepy;
108 fraction -= dx; // same as fraction -= 2*dx
109 }
110 x0 += stepx;
111 fraction += dy; // same as fraction -= 2*dy
112 sp_caxonomgrid_setpixel(buf, x0, y0, rgba);
113 }
114 } else {
115 int fraction = dx - (dy >> 1);
116 while (y0 != y1) {
117 if (fraction >= 0) {
118 x0 += stepx;
119 fraction -= dy;
120 }
121 y0 += stepy;
122 fraction += dx;
123 sp_caxonomgrid_setpixel(buf, x0, y0, rgba);
124 }
125 }
127 }
129 static void
130 sp_grid_vline (SPCanvasBuf *buf, gint x, gint ys, gint ye, guint32 rgba)
131 {
132 if ((x >= buf->rect.x0) && (x < buf->rect.x1)) {
133 guint r, g, b, a;
134 gint y0, y1, y;
135 guchar *p;
136 r = NR_RGBA32_R(rgba);
137 g = NR_RGBA32_G (rgba);
138 b = NR_RGBA32_B (rgba);
139 a = NR_RGBA32_A (rgba);
140 y0 = MAX (buf->rect.y0, ys);
141 y1 = MIN (buf->rect.y1, ye + 1);
142 p = buf->buf + (y0 - buf->rect.y0) * buf->buf_rowstride + (x - buf->rect.x0) * 3;
143 for (y = y0; y < y1; y++) {
144 p[0] = NR_COMPOSEN11_1111 (r, a, p[0]);
145 p[1] = NR_COMPOSEN11_1111 (g, a, p[1]);
146 p[2] = NR_COMPOSEN11_1111 (b, a, p[2]);
147 p += buf->buf_rowstride;
148 }
149 }
150 }
152 namespace Inkscape {
155 /**
156 * A DIRECT COPY-PASTE FROM DOCUMENT-PROPERTIES.CPP TO QUICKLY GET RESULTS
157 *
158 * Helper function that attachs widgets in a 3xn table. The widgets come in an
159 * array that has two entries per table row. The two entries code for four
160 * possible cases: (0,0) means insert space in first column; (0, non-0) means
161 * widget in columns 2-3; (non-0, 0) means label in columns 1-3; and
162 * (non-0, non-0) means two widgets in columns 2 and 3.
163 **/
164 #define SPACE_SIZE_X 15
165 #define SPACE_SIZE_Y 10
166 static inline void
167 attach_all(Gtk::Table &table, Gtk::Widget const *const arr[], unsigned size, int start = 0)
168 {
169 for (unsigned i=0, r=start; i<size/sizeof(Gtk::Widget*); i+=2) {
170 if (arr[i] && arr[i+1]) {
171 table.attach (const_cast<Gtk::Widget&>(*arr[i]), 1, 2, r, r+1,
172 Gtk::FILL|Gtk::EXPAND, (Gtk::AttachOptions)0,0,0);
173 table.attach (const_cast<Gtk::Widget&>(*arr[i+1]), 2, 3, r, r+1,
174 Gtk::FILL|Gtk::EXPAND, (Gtk::AttachOptions)0,0,0);
175 } else {
176 if (arr[i+1]) {
177 table.attach (const_cast<Gtk::Widget&>(*arr[i+1]), 1, 3, r, r+1,
178 Gtk::FILL|Gtk::EXPAND, (Gtk::AttachOptions)0,0,0);
179 } else if (arr[i]) {
180 Gtk::Label& label = reinterpret_cast<Gtk::Label&> (const_cast<Gtk::Widget&>(*arr[i]));
181 label.set_alignment (0.0);
182 table.attach (label, 0, 3, r, r+1,
183 Gtk::FILL|Gtk::EXPAND, (Gtk::AttachOptions)0,0,0);
184 } else {
185 Gtk::HBox *space = manage (new Gtk::HBox);
186 space->set_size_request (SPACE_SIZE_X, SPACE_SIZE_Y);
187 table.attach (*space, 0, 1, r, r+1,
188 (Gtk::AttachOptions)0, (Gtk::AttachOptions)0,0,0);
189 }
190 }
191 ++r;
192 }
193 }
195 CanvasAxonomGrid::CanvasAxonomGrid (SPNamedView * nv, Inkscape::XML::Node * in_repr, SPDocument * in_doc)
196 : CanvasGrid(nv, in_repr, in_doc, GRID_AXONOMETRIC), table(1, 1)
197 {
198 origin[NR::X] = prefs_get_double_attribute ("options.grids.axonom", "origin_x", 0.0);
199 origin[NR::Y] = prefs_get_double_attribute ("options.grids.axonom", "origin_y", 0.0);
200 color = prefs_get_int_attribute("options.grids.axonom", "color", 0x0000ff20);
201 empcolor = prefs_get_int_attribute("options.grids.axonom", "empcolor", 0x0000ff40);
202 empspacing = prefs_get_int_attribute("options.grids.axonom", "empspacing", 5);
203 gridunit = sp_unit_get_by_abbreviation( prefs_get_string_attribute("options.grids.axonom", "units") );
204 lengthy = prefs_get_double_attribute ("options.grids.axonom", "spacing_y", 1.0);
205 angle_deg[X] = prefs_get_double_attribute ("options.grids.axonom", "angle_x", 30.0);
206 angle_deg[Z] = prefs_get_double_attribute ("options.grids.axonom", "angle_z", 30.0);
207 angle_deg[Y] =0;
209 angle_rad[X] = deg_to_rad(angle_deg[X]);
210 tan_angle[X] = tan(angle_rad[X]);
211 angle_rad[Z] = deg_to_rad(angle_deg[Z]);
212 tan_angle[Z] = tan(angle_rad[Z]);
214 snapper = new CanvasAxonomGridSnapper(this, namedview, 0);
216 // initialize widgets:
217 vbox.set_border_width(2);
218 table.set_spacings(2);
219 vbox.pack_start(table, false, false, 0);
221 _wr.setUpdating (true);
222 Inkscape::UI::Widget::ScalarUnit * sutemp;
223 _rumg.init (_("Grid _units:"), "units", _wr, repr, doc);
224 _rsu_ox.init (_("_Origin X:"), _("X coordinate of grid origin"),
225 "originx", _rumg, _wr, repr, doc);
226 sutemp = _rsu_ox.getSU();
227 sutemp->setDigits(4);
228 sutemp->setIncrements(0.1, 1.0);
229 _rsu_oy.init (_("O_rigin Y:"), _("Y coordinate of grid origin"),
230 "originy", _rumg, _wr, repr, doc);
231 sutemp = _rsu_oy.getSU();
232 sutemp->setDigits(4);
233 sutemp->setIncrements(0.1, 1.0);
234 _rsu_sy.init (_("Spacing _Y:"), _("Base length of z-axis"),
235 "spacingy", _rumg, _wr, repr, doc);
236 sutemp = _rsu_sy.getSU();
237 sutemp->setDigits(4);
238 sutemp->setIncrements(0.1, 1.0);
239 _rsu_ax.init (_("Angle X:"), _("Angle of x-axis"),
240 "gridanglex", _rumg, _wr, repr, doc);
241 _rsu_az.init (_("Angle Z:"), _("Angle of z-axis"),
242 "gridanglez", _rumg, _wr, repr, doc);
243 _rcp_gcol.init (_("Grid line _color:"), _("Grid line color"),
244 _("Color of grid lines"), "color", "opacity", _wr, repr, doc);
245 _rcp_gmcol.init (_("Ma_jor grid line color:"), _("Major grid line color"),
246 _("Color of the major (highlighted) grid lines"),
247 "empcolor", "empopacity", _wr, repr, doc);
248 _rsi.init (_("_Major grid line every:"), _("lines"), "empspacing", _wr, repr, doc);
249 _wr.setUpdating (false);
251 Gtk::Widget const *const widget_array[] = {
252 0, _rcbgrid._button,
253 _rumg._label, _rumg._sel,
254 0, _rsu_ox.getSU(),
255 0, _rsu_oy.getSU(),
256 0, _rsu_sy.getSU(),
257 0, _rsu_ax.getSU(),
258 0, _rsu_az.getSU(),
259 _rcp_gcol._label, _rcp_gcol._cp,
260 0, 0,
261 _rcp_gmcol._label, _rcp_gmcol._cp,
262 _rsi._label, &_rsi._hbox,
263 };
265 attach_all (table, widget_array, sizeof(widget_array));
267 vbox.show();
269 if (repr) readRepr();
270 updateWidgets();
271 }
273 CanvasAxonomGrid::~CanvasAxonomGrid ()
274 {
275 if (snapper) delete snapper;
276 }
279 /* fixme: Collect all these length parsing methods and think common sane API */
281 static gboolean sp_nv_read_length(gchar const *str, guint base, gdouble *val, SPUnit const **unit)
282 {
283 if (!str) {
284 return FALSE;
285 }
287 gchar *u;
288 gdouble v = g_ascii_strtod(str, &u);
289 if (!u) {
290 return FALSE;
291 }
292 while (isspace(*u)) {
293 u += 1;
294 }
296 if (!*u) {
297 /* No unit specified - keep default */
298 *val = v;
299 return TRUE;
300 }
302 if (base & SP_UNIT_DEVICE) {
303 if (u[0] && u[1] && !isalnum(u[2]) && !strncmp(u, "px", 2)) {
304 *unit = &sp_unit_get_by_id(SP_UNIT_PX);
305 *val = v;
306 return TRUE;
307 }
308 }
310 if (base & SP_UNIT_ABSOLUTE) {
311 if (!strncmp(u, "pt", 2)) {
312 *unit = &sp_unit_get_by_id(SP_UNIT_PT);
313 } else if (!strncmp(u, "mm", 2)) {
314 *unit = &sp_unit_get_by_id(SP_UNIT_MM);
315 } else if (!strncmp(u, "cm", 2)) {
316 *unit = &sp_unit_get_by_id(SP_UNIT_CM);
317 } else if (!strncmp(u, "m", 1)) {
318 *unit = &sp_unit_get_by_id(SP_UNIT_M);
319 } else if (!strncmp(u, "in", 2)) {
320 *unit = &sp_unit_get_by_id(SP_UNIT_IN);
321 } else {
322 return FALSE;
323 }
324 *val = v;
325 return TRUE;
326 }
328 return FALSE;
329 }
331 static gboolean sp_nv_read_opacity(gchar const *str, guint32 *color)
332 {
333 if (!str) {
334 return FALSE;
335 }
337 gchar *u;
338 gdouble v = g_ascii_strtod(str, &u);
339 if (!u) {
340 return FALSE;
341 }
342 v = CLAMP(v, 0.0, 1.0);
344 *color = (*color & 0xffffff00) | (guint32) floor(v * 255.9999);
346 return TRUE;
347 }
351 void
352 CanvasAxonomGrid::readRepr()
353 {
354 gchar const *value;
355 if ( (value = repr->attribute("originx")) ) {
356 sp_nv_read_length(value, SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE, &origin[NR::X], &gridunit);
357 origin[NR::X] = sp_units_get_pixels(origin[NR::X], *(gridunit));
358 }
359 if ( (value = repr->attribute("originy")) ) {
360 sp_nv_read_length(value, SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE, &origin[NR::Y], &gridunit);
361 origin[NR::Y] = sp_units_get_pixels(origin[NR::Y], *(gridunit));
362 }
364 if ( (value = repr->attribute("spacingy")) ) {
365 sp_nv_read_length(value, SP_UNIT_ABSOLUTE | SP_UNIT_DEVICE, &lengthy, &gridunit);
366 lengthy = sp_units_get_pixels(lengthy, *(gridunit));
367 if (lengthy < 1.0) lengthy = 1.0;
368 }
370 if ( (value = repr->attribute("gridanglex")) ) {
371 angle_deg[X] = g_ascii_strtod(value, NULL);
372 if (angle_deg[X] < 1.0) angle_deg[X] = 1.0;
373 if (angle_deg[X] > 89.0) angle_deg[X] = 89.0;
374 angle_rad[X] = deg_to_rad(angle_deg[X]);
375 tan_angle[X] = tan(angle_rad[X]);
376 }
378 if ( (value = repr->attribute("gridanglez")) ) {
379 angle_deg[Z] = g_ascii_strtod(value, NULL);
380 if (angle_deg[Z] < 1.0) angle_deg[Z] = 1.0;
381 if (angle_deg[Z] > 89.0) angle_deg[Z] = 89.0;
382 angle_rad[Z] = deg_to_rad(angle_deg[Z]);
383 tan_angle[Z] = tan(angle_rad[Z]);
384 }
386 if ( (value = repr->attribute("color")) ) {
387 color = (color & 0xff) | sp_svg_read_color(value, color);
388 }
390 if ( (value = repr->attribute("empcolor")) ) {
391 empcolor = (empcolor & 0xff) | sp_svg_read_color(value, empcolor);
392 }
394 if ( (value = repr->attribute("opacity")) ) {
395 sp_nv_read_opacity(value, &color);
396 }
397 if ( (value = repr->attribute("empopacity")) ) {
398 sp_nv_read_opacity(value, &empcolor);
399 }
401 if ( (value = repr->attribute("empspacing")) ) {
402 empspacing = atoi(value);
403 }
405 if ( (value = repr->attribute("visible")) ) {
406 visible = (strcmp(value,"true") == 0);
407 }
409 if ( (value = repr->attribute("snap_enabled")) ) {
410 g_assert(snapper != NULL);
411 snapper->setEnabled(strcmp(value,"true") == 0);
412 }
414 for (GSList *l = canvasitems; l != NULL; l = l->next) {
415 sp_canvas_item_request_update ( SP_CANVAS_ITEM(l->data) );
416 }
417 return;
418 }
420 /**
421 * Called when XML node attribute changed; updates dialog widgets if change was not done by widgets themselves.
422 */
423 void
424 CanvasAxonomGrid::onReprAttrChanged(Inkscape::XML::Node */*repr*/, gchar const */*key*/, gchar const */*oldval*/, gchar const */*newval*/, bool /*is_interactive*/)
425 {
426 readRepr();
428 if ( ! (_wr.isUpdating()) )
429 updateWidgets();
430 }
435 Gtk::Widget &
436 CanvasAxonomGrid::getWidget()
437 {
438 return vbox;
439 }
442 /**
443 * Update dialog widgets from object's values.
444 */
445 void
446 CanvasAxonomGrid::updateWidgets()
447 {
448 if (_wr.isUpdating()) return;
450 _wr.setUpdating (true);
452 _rcb_visible.setActive(visible);
453 if (snapper != NULL) {
454 _rcb_snap_enabled.setActive(snapper->getEnabled());
455 }
457 _rumg.setUnit (gridunit);
459 gdouble val;
460 val = origin[NR::X];
461 val = sp_pixels_get_units (val, *(gridunit));
462 _rsu_ox.setValue (val);
463 val = origin[NR::Y];
464 val = sp_pixels_get_units (val, *(gridunit));
465 _rsu_oy.setValue (val);
466 val = lengthy;
467 double gridy = sp_pixels_get_units (val, *(gridunit));
468 _rsu_sy.setValue (gridy);
470 _rsu_ax.setValue(angle_deg[X]);
471 _rsu_az.setValue(angle_deg[Z]);
473 _rcp_gcol.setRgba32 (color);
474 _rcp_gmcol.setRgba32 (empcolor);
475 _rsi.setValue (empspacing);
477 _wr.setUpdating (false);
479 return;
480 }
484 void
485 CanvasAxonomGrid::Update (NR::Matrix const &affine, unsigned int /*flags*/)
486 {
487 ow = origin * affine;
488 sw = NR::Point(fabs(affine[0]),fabs(affine[3]));
490 for(int dim = 0; dim < 2; dim++) {
491 gint scaling_factor = empspacing;
493 if (scaling_factor <= 1)
494 scaling_factor = 5;
496 scaled = FALSE;
497 int watchdog = 0;
498 while ( (sw[dim] < 8.0) & (watchdog < 100) ) {
499 scaled = TRUE;
500 sw[dim] *= scaling_factor;
501 // First pass, go up to the major line spacing, then
502 // keep increasing by two.
503 scaling_factor = 2;
504 watchdog++;
505 }
507 }
509 spacing_ylines = sw[NR::X] * lengthy /(tan_angle[X] + tan_angle[Z]);
510 lyw = sw[NR::Y] * lengthy;
511 lxw_x = (lengthy / tan_angle[X]) * sw[NR::X];
512 lxw_z = (lengthy / tan_angle[Z]) * sw[NR::X];
514 if (empspacing == 0) {
515 scaled = TRUE;
516 }
518 }
520 void
521 CanvasAxonomGrid::Render (SPCanvasBuf *buf)
522 {
523 // gc = gridcoordinates (the coordinates calculated from the grids origin 'grid->ow'.
524 // sc = screencoordinates ( for example "buf->rect.x0" is in screencoordinates )
525 // bc = buffer patch coordinates
527 // tl = topleft ; br = bottomright
528 NR::Point buf_tl_gc;
529 NR::Point buf_br_gc;
530 buf_tl_gc[NR::X] = buf->rect.x0 - ow[NR::X];
531 buf_tl_gc[NR::Y] = buf->rect.y0 - ow[NR::Y];
532 buf_br_gc[NR::X] = buf->rect.x1 - ow[NR::X];
533 buf_br_gc[NR::Y] = buf->rect.y1 - ow[NR::Y];
535 gdouble x;
536 gdouble y;
538 // render the three separate line groups representing the main-axes
540 // x-axis always goes from topleft to bottomright. (0,0) - (1,1)
541 gdouble const xintercept_y_bc = (buf_tl_gc[NR::X] * tan_angle[X]) - buf_tl_gc[NR::Y] ;
542 gdouble const xstart_y_sc = ( xintercept_y_bc - floor(xintercept_y_bc/lyw)*lyw ) + buf->rect.y0;
543 gint const xlinestart = (gint) Inkscape::round( (xstart_y_sc - buf->rect.x0*tan_angle[X] -ow[NR::Y]) / lyw );
544 gint xlinenum = xlinestart;
545 // lines starting on left side.
546 for (y = xstart_y_sc; y < buf->rect.y1; y += lyw, xlinenum++) {
547 gint const x0 = buf->rect.x0;
548 gint const y0 = (gint) Inkscape::round(y);
549 gint const x1 = x0 + (gint) Inkscape::round( (buf->rect.y1 - y) / tan_angle[X] );
550 gint const y1 = buf->rect.y1;
552 if (!scaled && (xlinenum % empspacing) == 0) {
553 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, empcolor);
554 } else {
555 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, color);
556 }
557 }
558 // lines starting from top side
559 gdouble const xstart_x_sc = buf->rect.x0 + (lxw_x - (xstart_y_sc - buf->rect.y0) / tan_angle[X]) ;
560 xlinenum = xlinestart-1;
561 for (x = xstart_x_sc; x < buf->rect.x1; x += lxw_x, xlinenum--) {
562 gint const y0 = buf->rect.y0;
563 gint const y1 = buf->rect.y1;
564 gint const x0 = (gint) Inkscape::round(x);
565 gint const x1 = x0 + (gint) Inkscape::round( (y1 - y0) / tan_angle[X] );
567 if (!scaled && (xlinenum % empspacing) == 0) {
568 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, empcolor);
569 } else {
570 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, color);
571 }
572 }
574 // y-axis lines (vertical)
575 gdouble const ystart_x_sc = floor (buf_tl_gc[NR::X] / spacing_ylines) * spacing_ylines + ow[NR::X];
576 gint const ylinestart = (gint) Inkscape::round((ystart_x_sc - ow[NR::X]) / spacing_ylines);
577 gint ylinenum = ylinestart;
578 for (x = ystart_x_sc; x < buf->rect.x1; x += spacing_ylines, ylinenum++) {
579 gint const x0 = (gint) Inkscape::round(x);
581 if (!scaled && (ylinenum % empspacing) == 0) {
582 sp_grid_vline (buf, x0, buf->rect.y0, buf->rect.y1 - 1, empcolor);
583 } else {
584 sp_grid_vline (buf, x0, buf->rect.y0, buf->rect.y1 - 1, color);
585 }
586 }
588 // z-axis always goes from bottomleft to topright. (0,1) - (1,0)
589 gdouble const zintercept_y_bc = (buf_tl_gc[NR::X] * -tan_angle[Z]) - buf_tl_gc[NR::Y] ;
590 gdouble const zstart_y_sc = ( zintercept_y_bc - floor(zintercept_y_bc/lyw)*lyw ) + buf->rect.y0;
591 gint const zlinestart = (gint) Inkscape::round( (zstart_y_sc + buf->rect.x0*tan_angle[X] - ow[NR::Y]) / lyw );
592 gint zlinenum = zlinestart;
593 // lines starting from left side
594 for (y = zstart_y_sc; y < buf->rect.y1; y += lyw, zlinenum++) {
595 gint const x0 = buf->rect.x0;
596 gint const y0 = (gint) Inkscape::round(y);
597 gint const x1 = x0 + (gint) Inkscape::round( (y - buf->rect.y0 ) / tan_angle[Z] );
598 gint const y1 = buf->rect.y0;
600 if (!scaled && (zlinenum % empspacing) == 0) {
601 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, empcolor);
602 } else {
603 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, color);
604 }
605 }
606 // draw lines from bottom-up
607 gdouble const zstart_x_sc = buf->rect.x0 + (y - buf->rect.y1) / tan_angle[Z] ;
608 for (x = zstart_x_sc; x < buf->rect.x1; x += lxw_z, zlinenum++) {
609 gint const y0 = buf->rect.y1;
610 gint const y1 = buf->rect.y0;
611 gint const x0 = (gint) Inkscape::round(x);
612 gint const x1 = x0 + (gint) Inkscape::round( (buf->rect.y1 - buf->rect.y0) / tan_angle[Z] );
614 if (!scaled && (zlinenum % empspacing) == 0) {
615 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, empcolor);
616 } else {
617 sp_caxonomgrid_drawline (buf, x0, y0, x1, y1, color);
618 }
619 }
620 }
622 CanvasAxonomGridSnapper::CanvasAxonomGridSnapper(CanvasAxonomGrid *grid, SPNamedView const *nv, NR::Coord const d) : LineSnapper(nv, d)
623 {
624 this->grid = grid;
625 }
627 LineSnapper::LineList
628 CanvasAxonomGridSnapper::_getSnapLines(NR::Point const &p) const
629 {
630 LineList s;
632 if ( grid == NULL ) {
633 return s;
634 }
636 /* This is to make sure we snap to only visible grid lines */
637 double scaled_spacing_h = grid->spacing_ylines; // this is spacing of visible lines if screen pixels
638 double scaled_spacing_v = grid->lyw; // vertical
640 // convert screen pixels to px
641 // FIXME: after we switch to snapping dist in screen pixels, this will be unnecessary
642 if (SP_ACTIVE_DESKTOP) {
643 scaled_spacing_h /= SP_ACTIVE_DESKTOP->current_zoom();
644 scaled_spacing_v /= SP_ACTIVE_DESKTOP->current_zoom();
645 }
647 // In an axonometric grid, any point will be surrounded by 6 grid lines:
648 // - 2 vertical grid lines, one left and one right from the point
649 // - 2 angled z grid lines, one above and one below the point
650 // - 2 angled x grid lines, one above and one below the point
652 // Calculate the x coordinate of the vertical grid lines
653 NR::Coord x_max = Inkscape::Util::round_to_upper_multiple_plus(p[NR::X], scaled_spacing_h, grid->origin[NR::X]);
654 NR::Coord x_min = Inkscape::Util::round_to_lower_multiple_plus(p[NR::X], scaled_spacing_h, grid->origin[NR::X]);
656 // Calculate the y coordinate of the intersection of the angled grid lines with the y-axis
657 double y_proj_along_z = p[NR::Y] - grid->tan_angle[Z]*(p[NR::X] - grid->origin[NR::X]);
658 double y_proj_along_x = p[NR::Y] + grid->tan_angle[X]*(p[NR::X] - grid->origin[NR::X]);
659 double y_proj_along_z_max = Inkscape::Util::round_to_upper_multiple_plus(y_proj_along_z, scaled_spacing_v, grid->origin[NR::Y]);
660 double y_proj_along_z_min = Inkscape::Util::round_to_lower_multiple_plus(y_proj_along_z, scaled_spacing_v, grid->origin[NR::Y]);
661 double y_proj_along_x_max = Inkscape::Util::round_to_upper_multiple_plus(y_proj_along_x, scaled_spacing_v, grid->origin[NR::Y]);
662 double y_proj_along_x_min = Inkscape::Util::round_to_lower_multiple_plus(y_proj_along_x, scaled_spacing_v, grid->origin[NR::Y]);
664 // Calculate the normal for the angled grid lines
665 NR::Point norm_x = NR::rot90(NR::Point(1, -grid->tan_angle[X]));
666 NR::Point norm_z = NR::rot90(NR::Point(1, grid->tan_angle[Z]));
668 // The four angled grid lines form a parallellogram, enclosing the point
669 // One of the two vertical grid lines divides this parallellogram in two triangles
670 // We will now try to find out in which half (i.e. triangle) our point is, and return
671 // only the three grid lines defining that triangle
673 // The vertical grid line is at the intersection of two angled grid lines.
674 // Now go find that intersection!
675 Geom::Point result;
676 Geom::IntersectorKind is = line_intersection(norm_x.to_2geom(), norm_x[NR::Y]*y_proj_along_x_max,
677 norm_z.to_2geom(), norm_z[NR::Y]*y_proj_along_z_max,
678 result);
680 // Determine which half of the parallellogram to use
681 bool use_left_half = true;
682 bool use_right_half = true;
684 if (is == Geom::intersects) {
685 use_left_half = (p[NR::X] - grid->origin[NR::X]) < result[Geom::X];
686 use_right_half = !use_left_half;
687 }
689 //std::cout << "intersection at " << result << " leads to use_left_half = " << use_left_half << " and use_right_half = " << use_right_half << std::endl;
691 // Return the three grid lines which define the triangle that encloses our point
692 // If we didn't find an intersection above, all 6 grid lines will be returned
693 if (use_left_half) {
694 s.push_back(std::make_pair(norm_z, NR::Point(grid->origin[NR::X], y_proj_along_z_max)));
695 s.push_back(std::make_pair(norm_x, NR::Point(grid->origin[NR::X], y_proj_along_x_min)));
696 s.push_back(std::make_pair(component_vectors[NR::X], NR::Point(x_max, 0)));
697 }
699 if (use_right_half) {
700 s.push_back(std::make_pair(norm_z, NR::Point(grid->origin[NR::X], y_proj_along_z_min)));
701 s.push_back(std::make_pair(norm_x, NR::Point(grid->origin[NR::X], y_proj_along_x_max)));
702 s.push_back(std::make_pair(component_vectors[NR::X], NR::Point(x_min, 0)));
703 }
705 return s;
706 }
708 void CanvasAxonomGridSnapper::_addSnappedLine(SnappedConstraints &sc, NR::Point const snapped_point, NR::Coord const snapped_distance, NR::Point const normal_to_line, NR::Point const point_on_line) const
709 {
710 SnappedLine dummy = SnappedLine(snapped_point, snapped_distance, normal_to_line, point_on_line);
711 sc.grid_lines.push_back(dummy);
712 }
716 }; // namespace Inkscape
719 /*
720 Local Variables:
721 mode:c++
722 c-file-style:"stroustrup"
723 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
724 indent-tabs-mode:nil
725 fill-column:99
726 End:
727 */
728 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :