* Not ideal, but it is functional.

[scdataviz] / graph.c

diff --git a/graph.c b/graph.c
index 423ff84..df419b9 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -32,6 +32,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <graph.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <math.h>
+
+#ifdef DEBUG
+#define DEBUG_AUTOAXIS
+#endif
 
 G_DEFINE_TYPE(Graph, graph, G_TYPE_OBJECT);
 
@@ -44,6 +49,7 @@ static void graph_init(Graph *graph) {
   graph->symbol = CIRCLE;
   graph->points = g_ptr_array_new();
   graph->lines = NULL;
+  graph->xaxis = graph->yaxis = NULL;
 }
 
 Graph *graph_new(void) {
@@ -81,13 +87,34 @@ int graph_add_point(Graph* graph, double x, double y, const GString *label) {
   return 0;
 }
 
+int graph_add_graph_line(Graph* graph, struct graph_line *l) {
+  if(l == NULL) return 1;
+  if(graph->lines == NULL) {
+    if((graph->lines = g_ptr_array_new()) == NULL) return 1;
+  }
+  g_ptr_array_add(graph->lines, l);
+  if((graph->points->len == 0) && 
+     (graph->lines->len == 1)) {
+    graph->maxx = graph->minx = l->p0_x;
+    graph->maxy = graph->miny = l->p0_y;
+  }else{
+    if(l->p0_x > graph->maxx) graph->maxx = l->p0_x;
+    if(l->p0_x < graph->minx) graph->minx = l->p0_x;
+    if(l->p0_y > graph->maxy) graph->maxy = l->p0_y;
+    if(l->p0_y < graph->miny) graph->miny = l->p0_y;
+  }
+  if(l->p3_x > graph->maxx) graph->maxx = l->p3_x;
+  if(l->p3_x < graph->minx) graph->minx = l->p3_x;
+  if(l->p3_y > graph->maxy) graph->maxy = l->p3_y;
+  if(l->p3_y < graph->miny) graph->miny = l->p3_y;
+  return 0;
+}
+
+
 int graph_add_line(Graph* graph, double p0_x, double p0_y, double p1_x, double p1_y, double p2_x, double p2_y, double p3_x, double p3_y) {
   #ifdef DEBUG
   fprintf(stderr, "graph_add_line(%d, p0_x=%g, p0_y=%g, p1_x=%g, p1_y=%g, p2_x=%g, p2_y=%g, p3_x=%g, p3_y=%g\n", (unsigned int) graph, p0_x, p0_y, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
   #endif
-  if(graph->lines == NULL) {
-    if((graph->lines = g_ptr_array_new()) == NULL) return 1;
-  }
   struct graph_line *l;
   if((l=(struct graph_line*)malloc(sizeof(struct graph_line))) == NULL) return 2;
   l->p0_x=p0_x;
@@ -98,22 +125,7 @@ int graph_add_line(Graph* graph, double p0_x, double p0_y, double p1_x, double p
   l->p2_y=p2_y;
   l->p3_x=p3_x;
   l->p3_y=p3_y;
-  g_ptr_array_add(graph->lines, l);
-  if((graph->points->len == 0) && 
-     (graph->lines->len == 1)) {
-    graph->maxx = graph->minx = p0_x;
-    graph->maxy = graph->miny = p0_y;
-  }else{
-    if(p0_x > graph->maxx) graph->maxx = p0_x;
-    if(p0_x < graph->minx) graph->minx = p0_x;
-    if(p0_y > graph->maxy) graph->maxy = p0_y;
-    if(p0_y < graph->miny) graph->miny = p0_y;
-  }
-  if(p3_x > graph->maxx) graph->maxx = p3_x;
-  if(p3_x < graph->minx) graph->minx = p3_x;
-  if(p3_y > graph->maxy) graph->maxy = p3_y;
-  if(p3_y < graph->miny) graph->miny = p3_y;
-  return 0;
+  return graph_add_graph_line(graph, l);
 }
     
 struct cxt {
@@ -146,7 +158,77 @@ void graph_bezier_linear_to_cubic(double x0, double x3, double *x1, double *x2)
   *x2 = (2.0*x3 + x0)/3.0;
 }
 
-void graph_bezier_qudratic_to_cubic(double x0, double x3, double *x1, double *x2) {
-  *x2 = (x3 - x0)/3.0 + (*x1);
-  *x1 = (x0 - 3.0*(*x1))/2.0;
+void graph_bezier_linear_to_quadratic(double x0, double x3, double *x1) {
+  *x1 = (x3 + x0)/2.0;
+}
+
+void graph_bezier_quadratic_to_cubic(double x0, double x3, double *x1, double *x2) {
+  *x2 = (x3-2.0*(*x1))/3.0;
+  *x1 = (x0-2.0*(*x1))/3.0;
+}
+
+void graph_set_xaxis(Graph *g, struct graph_axis *axis) {
+  if(g->xaxis != NULL) {
+    free(g->xaxis);
+  }
+  g->xaxis=axis;
+}
+void graph_set_yaxis(Graph *g, struct graph_axis *axis) {
+  if(g->yaxis != NULL) {
+    free(g->yaxis);
+  }
+  g->yaxis=axis;
+}
+
+struct graph_axis* autoset_axis(Graph* g, GString* title, double min, double max) {
+  struct graph_axis *axis;
+  double range_mag;
+  double start_mag;
+  double stop_mag;
+  if(g->points->len == 0) {
+    return NULL;
+  }
+  if((axis=(struct graph_axis *)malloc(sizeof(struct graph_axis))) == NULL) {
+    return NULL;
+  }
+  if(g->points->len == 1) {
+    axis->major=1;
+    axis->minor=0;
+    axis->subminor=0;
+    axis->major_start=min;
+    axis->major_step=max;
+  }else{
+    range_mag = logb(max - min);
+    if(min == 0) 
+      start_mag = 0;
+    else
+      start_mag = copysign(pow(10, floor(log10(min))), min);
+    if(max == 0) 
+      stop_mag = 0;
+    else
+      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->major_start=start_mag;
+    axis->major_step=(stop_mag - start_mag)/(axis->major);
+  }
+  axis->title=g_string_new(title->str);
+  #ifdef DEBUG_AUTOAXIS
+  fprintf(stderr, "graph_autoset_xaxis: xmin=%g, log10(xmin)=%g, floor=%g, pow=%g round=%g\n", min, log10(min), floor(log10(min)), pow(10, floor(log10(min))), round(pow(10, floor(log10(min)))));
+  fprintf(stderr, "graph_autoset_xaxis: xmax=%g, log10(xmax)=%g, floor=%g, pow=%g round=%g\n", max, log10(max), floor(log10(max)), pow(10, floor(log10(max))), round(pow(10, floor(log10(max)))));
+  fprintf(stderr, "graph_autoset_xaxis: xmin=%g,max=%g start_mag=%g, stop_mag=%g range_mag=%g\n", min, max, start_mag, stop_mag, range_mag);
+  #endif
+  return axis;
+}
+
+int graph_autoset_xaxis(Graph *g, GString *title) {
+  graph_set_xaxis(g, autoset_axis(g, title, g->minx, g->maxx));
+  return 0;
+}
+
+int graph_autoset_yaxis(Graph *g, GString *title) {
+  graph_set_yaxis(g, autoset_axis(g, title, g->miny, g->maxy));
+  return 0;
 }