From: Scott Worley Date: Fri, 24 Feb 2023 04:37:21 +0000 (-0800) Subject: Don't draw connecting lines across large gaps X-Git-Url: http://git.scottworley.com/batteryviewer/commitdiff_plain/328956d5fb25e7ea8aae4f0d35de4b9fd05b1aa6 Don't draw connecting lines across large gaps --- diff --git a/chart.c b/chart.c index 835c63d..1fa76c5 100644 --- a/chart.c +++ b/chart.c @@ -24,6 +24,8 @@ struct BVChartPoint { G_DEFINE_TYPE_WITH_CODE(BVChart, bv_chart, GTK_TYPE_DRAWING_AREA, G_ADD_PRIVATE(BVChart)) +typedef void (*cairo_draw_func)(cairo_t *cr, double x, double y); + static gboolean bv_chart_draw(GtkWidget *widget, cairo_t *cr) { BVChart *chart = BV_CHART(widget); BVChartPrivate *priv = bv_chart_get_instance_private(chart); @@ -41,15 +43,17 @@ static gboolean bv_chart_draw(GtkWidget *widget, cairo_t *cr) { float xscale = (allocation.width - 2 * margin) / (priv->maxx - priv->minx); float yscale = (allocation.height - 2 * margin) / (priv->miny - priv->maxy); cairo_set_source_rgb(cr, 0.0, 0.0, 1.0); - struct BVChartPoint *start = - &g_array_index(priv->points, struct BVChartPoint, 0); - cairo_move_to(cr, xscale * (start->x - priv->minx) + margin, - yscale * (start->y - priv->maxy) + margin); - for (guint i = 1; i < priv->points->len; i++) { + float gap_threshold = 3.0; + float prevx = 0.0; + for (guint i = 0; i < priv->points->len; i++) { struct BVChartPoint *p = &g_array_index(priv->points, struct BVChartPoint, i); - cairo_line_to(cr, xscale * (p->x - priv->minx) + margin, - yscale * (p->y - priv->maxy) + margin); + gboolean is_gap = p->x - prevx > gap_threshold; + cairo_draw_func f = is_gap ? cairo_move_to : cairo_line_to; + float screen_x = xscale * (p->x - priv->minx) + margin; + float screen_y = yscale * (p->y - priv->maxy) + margin; + f(cr, screen_x, screen_y); + prevx = p->x; } cairo_stroke(cr);