From a421936992acf0bf71e2e38b938e00030df06054 Mon Sep 17 00:00:00 2001
From: Joseph Pingenot <bzrdude@digitasaru.net>
Date: Sat, 26 Jul 2008 21:53:18 -0500
Subject: [PATCH] * Axes work for what I have implemented thus far. * About to
 add in labels.

---
 graph.c       |    4 ++--
 graphwidget.c |   44 +++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/graph.c b/graph.c
index df419b9..f855cc9 100644
--- a/graph.c
+++ b/graph.c
@@ -209,8 +209,8 @@ struct graph_axis* autoset_axis(Graph* g, GString* title, double min, double max
       stop_mag = copysign(pow(10, ceil(log10(max))), max);
     if(stop_mag == start_mag) stop_mag *= 10;
     axis->major=10;
-    axis->minor=0;
-    axis->subminor=0;
+    axis->minor=9;
+    axis->subminor=9;
     axis->major_start=start_mag;
     axis->major_step=(stop_mag - start_mag)/(axis->major);
   }
diff --git a/graphwidget.c b/graphwidget.c
index 1c97eee..473aa49 100644
--- a/graphwidget.c
+++ b/graphwidget.c
@@ -35,6 +35,7 @@
 G_DEFINE_TYPE(GraphWidget, graph_widget, GTK_TYPE_DRAWING_AREA);
 
 #define INSET_PERCENT 0.1
+#define DEBUG_DRAW_AXIS
 
 struct drawing_context {
   GtkWidget *widget;
@@ -79,9 +80,37 @@ static void draw_lines(gpointer data, gpointer user_data) {
   cairo_curve_to(cxt->cr, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
 }
 
-static void draw_axis(gpointer data, gpointer user_data) {
-  struct graph_axis *xs = data;
-  struct drawing_context *cxt = user_data;
+static void draw_axis(struct drawing_context* cxt, struct graph_axis *axis, double scaling, double offset) {
+  #ifdef DEBUG_DRAW_AXIS
+  fprintf(stderr, "draw_axis; major_start=%g, major_step=%g, >major=%d, minor=%d, subminor=%d, label=%s\n", axis->major_start, axis->major_step, axis->major, axis->minor, axis->subminor, axis->title->str);
+  #endif
+  cairo_move_to(cxt->cr, 0, 0);
+  cairo_line_to(cxt->cr, 1, 0);
+  register int i, j, k;
+  register double pos, mpos, smpos;
+  for(i=0; i<axis->major; i++) {
+    pos=i*axis->major_step + axis->major_start;
+    cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
+    cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
+    for(k=0; k<axis->subminor; k++) {
+      smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + pos;
+      cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
+      cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
+    }
+    for(j=0; j<axis->minor; j++) {
+      mpos=(j+1)*(axis->major_step/(axis->minor+1)) + pos;
+      cairo_move_to(cxt->cr, (mpos + offset)*scaling, 0);
+      cairo_line_to(cxt->cr, (mpos + offset)*scaling, 0.025);
+      for(k=0; k<axis->subminor; k++) {
+	smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + mpos;
+	cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
+	cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
+      }
+    }
+  }
+  pos=i*axis->major_step + axis->major_start;
+  cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
+  cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
 }
 
 static void draw(GtkWidget *graph, cairo_t *cr) {
@@ -139,6 +168,15 @@ static void draw(GtkWidget *graph, cairo_t *cr) {
   cairo_fill_preserve(cr);
   cairo_set_source_rgb(cr, 0, 0, 0);
   g_ptr_array_foreach(gw->graph->points, &draw_point, (gpointer)&cxt);
+  if(gw->graph->xaxis != NULL) 
+    draw_axis(&cxt, gw->graph->xaxis, cxt.xscaling, cxt.xoffset);
+  if(gw->graph->yaxis != NULL) {
+    cairo_save(cr);
+    cairo_matrix_t matrix = { .xx=0, .xy = 1, .x0 = 0, .yx = 1, .yy = 0, .y0 = 0 };
+    cairo_transform(cr, &matrix);
+    draw_axis(&cxt, gw->graph->yaxis, cxt.yscaling, cxt.yoffset);
+    cairo_restore(cr);
+  }
   cairo_stroke(cr);
   cairo_restore(cr);
 }
-- 
1.7.9.5