* Seems to be coming along. Not convinced that the bowing conversions are right.

[scdataviz] / graph.c

diff --git a/graph.c b/graph.c
index 423ff84..1af3cb8 100644 (file)
--- a/graph.c
+++ b/graph.c
@@ -81,13 +81,33 @@ 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(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 +118,7 @@ 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 +151,11 @@ 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;
 }