Code

Split SPCanvasItem and SPCanvasGroup to individual .h files. Removed forward header.
[inkscape.git] / src / display / guideline.cpp
index fcddbb0e6e5fd86e4f25abc8ee16fc99e7060634..ce1289faf30adf6a0d73ed97ac6338f937da14b9 100644 (file)
@@ -1,32 +1,35 @@
-#define __SP_GUIDELINE_C__
-
 /*
  * Horizontal/vertical but can also be angled line
  *
  * Authors:
  *   Lauris Kaplinski <lauris@kaplinski.com>
  *   Johan Engelen
+ *   Maximilian Albert <maximilian.albert@gmail.com>
  *
  * Copyright (C) 2000-2002 Lauris Kaplinski
  * Copyright (C) 2007 Johan Engelen
+ * Copyright (C) 2009 Maximilian Albert
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
 
 #include <libnr/nr-pixops.h>
-#include "display-forward.h"
+#include <2geom/transforms.h>
 #include "sp-canvas-util.h"
+#include "sp-ctrlpoint.h"
 #include "guideline.h"
 
 static void sp_guideline_class_init(SPGuideLineClass *c);
 static void sp_guideline_init(SPGuideLine *guideline);
 static void sp_guideline_destroy(GtkObject *object);
 
-static void sp_guideline_update(SPCanvasItem *item, NR::Matrix const &affine, unsigned int flags);
+static void sp_guideline_update(SPCanvasItem *item, Geom::Matrix const &affine, unsigned int flags);
 static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf);
 
-static double sp_guideline_point(SPCanvasItem *item, NR::Point p, SPCanvasItem **actual_item);
+static double sp_guideline_point(SPCanvasItem *item, Geom::Point p, SPCanvasItem **actual_item);
+
+static void sp_guideline_drawline (SPCanvasBuf *buf, gint x0, gint y0, gint x1, gint y1, guint32 rgba);
 
 static SPCanvasItemClass *parent_class;
 
@@ -70,12 +73,27 @@ static void sp_guideline_init(SPGuideLine *gl)
     gl->rgba = 0x0000ff7f;
 
     gl->normal_to_line = Geom::Point(0,1);
+    gl->angle = 3.14159265358979323846/2;
     gl->point_on_line = Geom::Point(0,0);
     gl->sensitive = 0;
+
+    gl->origin = NULL;
 }
 
 static void sp_guideline_destroy(GtkObject *object)
 {
+    g_return_if_fail (object != NULL);
+    g_return_if_fail (SP_IS_GUIDELINE (object));
+    //g_return_if_fail (SP_GUIDELINE(object)->origin != NULL);
+    //g_return_if_fail (SP_IS_CTRLPOINT(SP_GUIDELINE(object)->origin));
+    
+    if (SP_GUIDELINE(object)->origin != NULL && SP_IS_CTRLPOINT(SP_GUIDELINE(object)->origin)) {
+        gtk_object_destroy(GTK_OBJECT(SP_GUIDELINE(object)->origin));
+    } else {
+        // FIXME: This branch shouldn't be reached (although it seems to be harmless).
+        //g_error("Why can it be that gl->origin is not a valid SPCtrlPoint?\n");
+    }
+
     GTK_OBJECT_CLASS(parent_class)->destroy(object);
 }
 
@@ -90,8 +108,8 @@ static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf)
     unsigned int const b = NR_RGBA32_B (gl->rgba);
     unsigned int const a = NR_RGBA32_A (gl->rgba);
 
-    if (gl->normal_to_line[Geom::Y] == 0.) {
-        int position = gl->point_on_line[Geom::X];
+    if (gl->is_vertical()) {
+        int position = (int) Inkscape::round(gl->point_on_line[Geom::X]);
         if (position < buf->rect.x0 || position >= buf->rect.x1) {
             return;
         }
@@ -99,7 +117,7 @@ static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf)
         int p0 = buf->rect.y0;
         int p1 = buf->rect.y1;
         int step = buf->buf_rowstride;
-        unsigned char *d = buf->buf + 3 * (position - buf->rect.x0);
+        unsigned char *d = buf->buf + 4 * (position - buf->rect.x0);
 
         for (int p = p0; p < p1; p++) {
             d[0] = NR_COMPOSEN11_1111(r, a, d[0]);
@@ -107,15 +125,15 @@ static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf)
             d[2] = NR_COMPOSEN11_1111(b, a, d[2]);
             d += step;
         }
-    } else if (gl->normal_to_line[Geom::X] == 0.) {
-        int position = gl->point_on_line[Geom::Y];
+    } else if (gl->is_horizontal()) {
+        int position = (int) Inkscape::round(gl->point_on_line[Geom::Y]);
         if (position < buf->rect.y0 || position >= buf->rect.y1) {
             return;
         }
 
         int p0 = buf->rect.x0;
         int p1 = buf->rect.x1;
-        int step = 3;
+        int step = 4;
         unsigned char *d = buf->buf + (position - buf->rect.y0) * buf->buf_rowstride;
 
         for (int p = p0; p < p1; p++) {
@@ -125,11 +143,47 @@ static void sp_guideline_render(SPCanvasItem *item, SPCanvasBuf *buf)
             d += step;
         }
     } else {
-        // render angled line
+        // render angled line, once intersection has been detected, draw from there.
+        Geom::Point parallel_to_line( gl->normal_to_line[Geom::Y],
+                                      /*should be minus, but inverted y axis*/ gl->normal_to_line[Geom::X]);
+
+        //try to intersect with left vertical of rect
+        double y_intersect_left = (buf->rect.x0 - gl->point_on_line[Geom::X]) * parallel_to_line[Geom::Y] / parallel_to_line[Geom::X] + gl->point_on_line[Geom::Y];
+        if ( (y_intersect_left >= buf->rect.y0) && (y_intersect_left <= buf->rect.y1) ) {
+            // intersects with left vertical!
+            double y_intersect_right = (buf->rect.x1 - gl->point_on_line[Geom::X]) * parallel_to_line[Geom::Y] / parallel_to_line[Geom::X] + gl->point_on_line[Geom::Y];
+            sp_guideline_drawline (buf, buf->rect.x0, static_cast<gint>(round(y_intersect_left)), buf->rect.x1, static_cast<gint>(round(y_intersect_right)), gl->rgba);
+            return;
+        }
+
+        //try to intersect with right vertical of rect
+        double y_intersect_right = (buf->rect.x1 - gl->point_on_line[Geom::X]) * parallel_to_line[Geom::Y] / parallel_to_line[Geom::X] + gl->point_on_line[Geom::Y];
+        if ( (y_intersect_right >= buf->rect.y0) && (y_intersect_right <= buf->rect.y1) ) {
+            // intersects with right vertical!
+            sp_guideline_drawline (buf, buf->rect.x1, static_cast<gint>(round(y_intersect_right)), buf->rect.x0, static_cast<gint>(round(y_intersect_left)), gl->rgba);
+            return;
+        }
+
+        //try to intersect with top horizontal of rect
+        double x_intersect_top = (buf->rect.y0 - gl->point_on_line[Geom::Y]) * parallel_to_line[Geom::X] / parallel_to_line[Geom::Y] + gl->point_on_line[Geom::X];
+        if ( (x_intersect_top >= buf->rect.x0) && (x_intersect_top <= buf->rect.x1) ) {
+            // intersects with top horizontal!
+            double x_intersect_bottom = (buf->rect.y1 - gl->point_on_line[Geom::Y]) * parallel_to_line[Geom::X] / parallel_to_line[Geom::Y] + gl->point_on_line[Geom::X];
+            sp_guideline_drawline (buf, static_cast<gint>(round(x_intersect_top)), buf->rect.y0, static_cast<gint>(round(x_intersect_bottom)), buf->rect.y1, gl->rgba);
+            return;
+        }
+
+        //try to intersect with bottom horizontal of rect
+        double x_intersect_bottom = (buf->rect.y1 - gl->point_on_line[Geom::Y]) * parallel_to_line[Geom::X] / parallel_to_line[Geom::Y] + gl->point_on_line[Geom::X];
+        if ( (x_intersect_top >= buf->rect.x0) && (x_intersect_top <= buf->rect.x1) ) {
+            // intersects with bottom horizontal!
+            sp_guideline_drawline (buf, static_cast<gint>(round(x_intersect_bottom)), buf->rect.y1, static_cast<gint>(round(x_intersect_top)), buf->rect.y0, gl->rgba);
+            return;
+        }
     }
 }
 
-static void sp_guideline_update(SPCanvasItem *item, NR::Matrix const &affine, unsigned int flags)
+static void sp_guideline_update(SPCanvasItem *item, Geom::Matrix const &affine, unsigned int flags)
 {
     SPGuideLine *gl = SP_GUIDELINE(item);
 
@@ -140,15 +194,20 @@ static void sp_guideline_update(SPCanvasItem *item, NR::Matrix const &affine, un
     gl->point_on_line[Geom::X] = affine[4];
     gl->point_on_line[Geom::Y] = affine[5];
 
-    if (gl->normal_to_line[Geom::Y] == 1.) {
-        sp_canvas_update_bbox (item, -1000000, -1000000, 1000000, 1000000);
+    sp_ctrlpoint_set_coords(gl->origin, gl->point_on_line * affine.inverse());
+    sp_canvas_item_request_update(SP_CANVAS_ITEM (gl->origin));
+
+    if (gl->is_horizontal()) {
+        sp_canvas_update_bbox (item, -1000000, (int) Inkscape::round(gl->point_on_line[Geom::Y]), 1000000, (int) Inkscape::round(gl->point_on_line[Geom::Y] + 1));
+    } else if (gl->is_vertical()) {
+        sp_canvas_update_bbox (item, (int) Inkscape::round(gl->point_on_line[Geom::X]), -1000000, (int) Inkscape::round(gl->point_on_line[Geom::X] + 1), 1000000);
     } else {
         sp_canvas_update_bbox (item, -1000000, -1000000, 1000000, 1000000);
     }
 }
 
 // Returns 0.0 if point is on the guideline
-static double sp_guideline_point(SPCanvasItem *item, NR::Point p, SPCanvasItem **actual_item)
+static double sp_guideline_point(SPCanvasItem *item, Geom::Point p, SPCanvasItem **actual_item)
 {
     SPGuideLine *gl = SP_GUIDELINE (item);
 
@@ -158,32 +217,48 @@ static double sp_guideline_point(SPCanvasItem *item, NR::Point p, SPCanvasItem *
 
     *actual_item = item;
 
-    double distance = Geom::dot((p.to_2geom() - gl->point_on_line), gl->normal_to_line);
+    Geom::Point vec(gl->normal_to_line[Geom::X], - gl->normal_to_line[Geom::Y]);
+    double distance = Geom::dot((p - gl->point_on_line), vec);
     return MAX(fabs(distance)-1, 0);
 }
 
 SPCanvasItem *sp_guideline_new(SPCanvasGroup *parent, Geom::Point point_on_line, Geom::Point normal)
 {
     SPCanvasItem *item = sp_canvas_item_new(parent, SP_TYPE_GUIDELINE, NULL);
+    SPCanvasItem *origin = sp_canvas_item_new(parent, SP_TYPE_CTRLPOINT, NULL);
 
     SPGuideLine *gl = SP_GUIDELINE(item);
+    SPCtrlPoint *cp = SP_CTRLPOINT(origin);
+    gl->origin = cp;
 
     normal.normalize();
     gl->normal_to_line = normal;
+    gl->angle = tan( -gl->normal_to_line[Geom::X] / gl->normal_to_line[Geom::Y]);
     sp_guideline_set_position(gl, point_on_line);
 
+    sp_ctrlpoint_set_coords(cp, point_on_line);
+
     return item;
 }
 
 void sp_guideline_set_position(SPGuideLine *gl, Geom::Point point_on_line)
 {
-    sp_canvas_item_affine_absolute(SP_CANVAS_ITEM (gl),
-                                   NR::Matrix(NR::translate(point_on_line)));
+    sp_canvas_item_affine_absolute(SP_CANVAS_ITEM (gl), Geom::Matrix(Geom::Translate(point_on_line)));
+    sp_canvas_item_affine_absolute(SP_CANVAS_ITEM (gl->origin), Geom::Matrix(Geom::Translate(point_on_line)));
+}
+
+void sp_guideline_set_normal(SPGuideLine *gl, Geom::Point normal_to_line)
+{
+    gl->normal_to_line = normal_to_line;
+    gl->angle = tan( -normal_to_line[Geom::X] / normal_to_line[Geom::Y]);
+
+    sp_canvas_item_request_update(SP_CANVAS_ITEM (gl));
 }
 
 void sp_guideline_set_color(SPGuideLine *gl, unsigned int rgba)
 {
     gl->rgba = rgba;
+    sp_ctrlpoint_set_color(gl->origin, rgba);
 
     sp_canvas_item_request_update(SP_CANVAS_ITEM(gl));
 }
@@ -193,6 +268,89 @@ void sp_guideline_set_sensitive(SPGuideLine *gl, int sensitive)
     gl->sensitive = sensitive;
 }
 
+void sp_guideline_delete(SPGuideLine *gl)
+{
+    //gtk_object_destroy(GTK_OBJECT(gl->origin));
+    gtk_object_destroy(GTK_OBJECT(gl));
+}
+
+//##########################################################
+// Line rendering
+#define SAFE_SETPIXEL   //undefine this when it is certain that setpixel is never called with invalid params
+
+/**
+    \brief  This function renders a pixel on a particular buffer.
+
+    The topleft of the buffer equals
+                        ( rect.x0 , rect.y0 )  in screen coordinates
+                        ( 0 , 0 )  in setpixel coordinates
+    The bottomright of the buffer equals
+                        ( rect.x1 , rect,y1 )  in screen coordinates
+                        ( rect.x1 - rect.x0 , rect.y1 - rect.y0 )  in setpixel coordinates
+*/
+static void
+sp_guideline_setpixel (SPCanvasBuf *buf, gint x, gint y, guint32 rgba)
+{
+#ifdef SAFE_SETPIXEL
+    if ( (x >= buf->rect.x0) && (x < buf->rect.x1) && (y >= buf->rect.y0) && (y < buf->rect.y1) ) {
+#endif
+        guint r, g, b, a;
+        r = NR_RGBA32_R (rgba);
+        g = NR_RGBA32_G (rgba);
+        b = NR_RGBA32_B (rgba);
+        a = NR_RGBA32_A (rgba);
+        guchar * p = buf->buf + (y - buf->rect.y0) * buf->buf_rowstride + (x - buf->rect.x0) * 4;
+        p[0] = NR_COMPOSEN11_1111 (r, a, p[0]);
+        p[1] = NR_COMPOSEN11_1111 (g, a, p[1]);
+        p[2] = NR_COMPOSEN11_1111 (b, a, p[2]);
+#ifdef SAFE_SETPIXEL
+    }
+#endif
+}
+
+/**
+    \brief  This function renders a line on a particular canvas buffer,
+            using Bresenham's line drawing function.
+            http://www.cs.unc.edu/~mcmillan/comp136/Lecture6/Lines.html
+            Coordinates are interpreted as SCREENcoordinates
+*/
+static void
+sp_guideline_drawline (SPCanvasBuf *buf, gint x0, gint y0, gint x1, gint y1, guint32 rgba)
+{
+    int dy = y1 - y0;
+    int dx = x1 - x0;
+    int stepx, stepy;
+
+    if (dy < 0) { dy = -dy;  stepy = -1; } else { stepy = 1; }
+    if (dx < 0) { dx = -dx;  stepx = -1; } else { stepx = 1; }
+    dy <<= 1;                                                  // dy is now 2*dy
+    dx <<= 1;                                                  // dx is now 2*dx
+
+    sp_guideline_setpixel(buf, x0, y0, rgba);
+    if (dx > dy) {
+        int fraction = dy - (dx >> 1);                         // same as 2*dy - dx
+        while (x0 != x1) {
+            if (fraction >= 0) {
+                y0 += stepy;
+                fraction -= dx;                                // same as fraction -= 2*dx
+            }
+            x0 += stepx;
+            fraction += dy;                                    // same as fraction -= 2*dy
+            sp_guideline_setpixel(buf, x0, y0, rgba);
+        }
+    } else {
+        int fraction = dx - (dy >> 1);
+        while (y0 != y1) {
+            if (fraction >= 0) {
+                x0 += stepx;
+                fraction -= dy;
+            }
+            y0 += stepy;
+            fraction += dx;
+            sp_guideline_setpixel(buf, x0, y0, rgba);
+        }
+    }
+}
 
 /*
   Local Variables:
@@ -203,4 +361,4 @@ void sp_guideline_set_sensitive(SPGuideLine *gl, int sensitive)
   fill-column:99
   End:
 */
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :