[Plplot-cvs] SF.net SVN: plplot:[11166] trunk/src/pllegend.c

[<hez...@us...>]

Revision: 11166
          http://plplot.svn.sourceforge.net/plplot/?rev=11166&view=rev
Author:   hezekiahcarty
Date:     2010-09-11 04:44:06 +0000 (Sat, 11 Sep 2010)

Log Message:
-----------
Actually commit pllegend.c

Added Paths:
-----------
    trunk/src/pllegend.c

Added: trunk/src/pllegend.c
===================================================================
--- trunk/src/pllegend.c	                        (rev 0)
+++ trunk/src/pllegend.c	2010-09-11 04:44:06 UTC (rev 11166)
@@ -0,0 +1,145 @@
+/* pllegend()
+ *
+ * Author: Hezekiah Carty 2010
+ *
+ * Copyright (C) 2010  Hezekiah M. Carty
+ *
+ * This file is part of PLplot.
+ *
+ * PLplot is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Library Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * PLplot is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with PLplot; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "plplotP.h"
+
+PLFLT get_character_height() {
+    // Character height in mm
+    PLFLT default_mm, char_height_mm;
+    // Normalized viewport limits
+    PLFLT vxmin, vxmax, vymin, vymax;
+    PLFLT vy;
+    // Size of subpage in mm
+    PLFLT mxmin, mxmax, mymin, mymax;
+    PLFLT mm_y;
+    // World height in mm
+    PLFLT world_height_mm;
+    // Normalized character height
+    PLFLT char_height_norm;
+    // Window dimensions
+    PLFLT wxmin, wxmax, wymin, wymax;
+    PLFLT world_y;
+
+    plgchr(&default_mm, &char_height_mm);
+    plgvpd(&vxmin, &vxmax, &vymin, &vymax);
+    vy = vymax - vymin;
+
+    plgspa(&mxmin, &mxmax, &mymin, &mymax);
+    mm_y = mymax - mymin;
+
+    world_height_mm = mm_y * vy;
+
+    // Character height (mm) / World height (mm) = Normalized char height
+    char_height_norm = char_height_mm / world_height_mm;
+
+    // Normalized character height * World height (world) =
+    // Character height (world)
+    plgvpw(&wxmin, &wxmax, &wymin, &wymax);
+    world_y = wymax - wymin;
+
+    return(char_height_norm * world_y);
+}
+
+#define normalized_to_world_x(nx) ((xmin) + (nx) * ((xmax) - (xmin)))
+#define normalized_to_world_y(ny) ((ymin) + (ny) * ((ymax) - (ymin)))
+
+// pllegend - Draw a legend using lines or points
+// line_length: How long should the lines be/how far apart are the points
+// x, y: Normalized position of the legend in the plot window
+// n: Number of legend entries
+// text_colors: Color map 0 indices of the colors to use for label text
+// names: Name/label for each legend entry
+// colors: Line/point color for each legend entry
+// symbols: Symbol to draw for each legend entry (NULL for lines)
+void c_pllegend(PLFLT line_length, PLFLT x, PLFLT y, PLINT n, PLINT *text_colors, char **names, PLINT *colors, PLINT *symbols) {
+    // Active indexed drawing color
+    PLINT old_col0;
+    // Viewport world-coordinate limits
+    PLFLT xmin, xmax, ymin, ymax;
+    // Legend position
+    PLFLT line_x, line_x_end, line_x_world, line_x_end_world;
+    PLFLT line_y, line_y_world;
+    PLFLT text_x, text_y, text_x_world, text_y_world;
+    // Character height (world coordinates)
+    PLFLT character_height;
+    // y-position of the current legend entry
+    PLFLT ty;
+    // Positions of the legend entries
+    PLFLT xs[2], ys[2];
+    PLINT i;
+
+    old_col0 = plsc->icol0;
+
+    plgvpw(&xmin, &xmax, &ymin, &ymax);
+
+    // World coordinates for legend lines
+    line_x = x;
+    line_y = y;
+    line_x_end = line_x + 0.1;
+    line_x_world = normalized_to_world_x(line_x);
+    line_y_world = normalized_to_world_y(line_y);
+    line_x_end_world = normalized_to_world_x(line_x_end);
+
+    // Get world-coordinate positions of the start of the legend text
+    text_x = line_x_end + 0.01;
+    text_y = line_y;
+    text_x_world = normalized_to_world_x(text_x);
+    text_y_world = normalized_to_world_y(text_y);
+
+    character_height = get_character_height();
+    // Starting y position for legend entries
+    ty = text_y_world - character_height;
+
+    xs[0] = line_x_world;
+    xs[1] = line_x_end_world;
+    ys[0] = ty;
+    ys[1] = ty;
+
+    // Draw each legend entry
+    for (i = 0; i < n; i++) {
+        // Line for the legend
+        plcol0(colors[i]);
+        if (symbols == NULL) {
+            // Draw lines
+            plline(2, xs, ys);
+        }
+        else {
+            // Draw symbols
+            plpoin(2, xs, ys, symbols[i]);
+        }
+
+        // Label/name for the legend
+        plcol0(text_colors[i]);
+        plptex(text_x_world, ty, 0.0, 0.0, 0.0, names[i]);
+        // Move to the next position
+        ty = ty - (1.5 * character_height);
+        ys[0] = ty;
+        ys[1] = ty;
+    }
+
+    // Restore the previously active drawing color
+    plcol0(old_col0);
+
+    return;
+}
+


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