Track min & max coordinates

[batteryviewer] / chart.c

diff --git a/chart.c b/chart.c
index 3efd454b3c454a8af64cae3d32ac9ba8aad27b2d..27057839c0618502c34d3dbb225d54b5077bb779 100644 (file)
--- a/chart.c
+++ b/chart.c
@@ -4,6 +4,7 @@
  */
 
 #include "chart.h"
+#include <float.h>
 #include <gtk/gtk.h>
 
 #define BV_CHART_PRIVATE(obj)                                                  \
@@ -12,7 +13,12 @@
 typedef struct _BVChartPrivate BVChartPrivate;
 
 struct _BVChartPrivate {
-  int temp;
+  GArray *points;
+  float minx, miny, maxx, maxy;
+};
+
+struct BVChartPoint {
+  float x, y;
 };
 
 G_DEFINE_TYPE_WITH_CODE(BVChart, bv_chart, GTK_TYPE_DRAWING_AREA,
@@ -22,8 +28,31 @@ static void bv_chart_class_init(BVChartClass *klass __attribute__((unused))) {}
 
 static void bv_chart_init(BVChart *chart) {
   gtk_widget_set_has_window(GTK_WIDGET(chart), FALSE);
+  BVChartPrivate *priv = bv_chart_get_instance_private(chart);
+  gboolean zero_terminated = FALSE;
+  gboolean clear_ = FALSE;
+  priv->points =
+      g_array_new(zero_terminated, clear_, sizeof(struct BVChartPoint));
+  priv->minx = FLT_MAX;
+  priv->miny = FLT_MAX;
+  priv->maxx = FLT_MIN;
+  priv->maxy = FLT_MIN;
 }
 
 GtkWidget *bv_chart_new() {
   return GTK_WIDGET(g_object_new(bv_chart_get_type(), NULL));
 }
+
+void bv_chart_add_point(BVChart *chart, float x, float y) {
+  BVChartPrivate *priv = bv_chart_get_instance_private(chart);
+  if (x < priv->minx)
+    priv->minx = x;
+  if (y < priv->miny)
+    priv->miny = y;
+  if (x > priv->maxx)
+    priv->maxx = x;
+  if (y > priv->maxy)
+    priv->maxy = y;
+  struct BVChartPoint p = {.x = x, .y = y};
+  g_array_append_val(priv->points, p);
+}