Fix some grid/ticks being draw too many/too few

Author: drahnr

src/goat-plot.c

@@ -366,16 +366,23 @@ static gboolean draw (GtkWidget *widget, cairo_t *cr)
 const gint width = allocation.width - padding.left - padding.right;
 const gint height = allocation.height - padding.top - padding.bottom;
 
+g_printf ("--- w=%i h=%i\n", width, height);
 gdouble ref_x_min = +G_MAXDOUBLE;
 gdouble ref_x_max = -G_MAXDOUBLE;
 gdouble ref_y_min = +G_MAXDOUBLE;
 gdouble ref_y_max = -G_MAXDOUBLE;
-goat_scale_get_range (priv->scale_x, &ref_x_min, &ref_x_max);
-goat_scale_get_range (priv->scale_y, &ref_y_min, &ref_y_max);
 
-// draw the actual data
+// get the common extends of all data sets if any scale used is set to autorange
+//
+// vfunc, we use it in a loop, so caching is good idea
 const gboolean register autorange_x = goat_scale_is_auto_range (priv->scale_x);
 const gboolean register autorange_y = goat_scale_is_auto_range (priv->scale_y);
+if (!autorange_x) {
+goat_scale_get_range (priv->scale_x, &ref_x_min, &ref_x_max);
+}
+if (!autorange_y) {
+goat_scale_get_range (priv->scale_y, &ref_y_min, &ref_y_max);
+}
 if (autorange_x || autorange_y) {
 
 for (i = 0; i < priv->array->len; i++) {
@@ -399,19 +406,17 @@ static gboolean draw (GtkWidget *widget, cairo_t *cr)
 goat_scale_update_range (priv->scale_x, ref_x_min, ref_x_max);
 goat_scale_update_range (priv->scale_y, ref_y_min, ref_y_max);
 
-g_printf ("x range %lf %lf\n", ref_x_min, ref_x_max);
-g_printf ("y range %lf %lf\n", ref_y_min, ref_y_max);
-
 // TODO add some fixup if x_min is very close to x_max
 // TODO add some additional padding for niceness :)
+// TODO think about extra padding to compensate marker sizes
 }
 gboolean draw = TRUE;
 if (!get_unit_to_pixel_factor (width, ref_x_min, ref_x_max, &x_unit_to_pixel)) {
-g_warning ("Bad x range. This is too boring to plot. %lf", x_unit_to_pixel);
+g_warning ("Bad x range");
 draw = FALSE;
 }
 if (!get_unit_to_pixel_factor (height, ref_y_min, ref_y_max, &y_unit_to_pixel)) {
-g_warning ("Bad y range. This is too boring to plot. %lf", y_unit_to_pixel);
+g_warning ("Bad y range");
 draw = FALSE;
 }
 

src/goat-scale-linear.c

@@ -173,6 +173,10 @@ void goat_scale_linear_set_ticks (GoatScaleLinear *scale, gdouble major, gint mi
 }
 
 
+static inline gboolean is_major_tick (gint i, gint minors_per_major)
+{
+return (i == 0) || (i % minors_per_major == 0);
+}
 /**
  * @param x/y-nil in pixel
  * @param x/y-factor convert unit to pixel
@@ -184,11 +188,7 @@ static void draw (GoatScale *scale, cairo_t *cr, gint left, gint right, gint top
 GoatScaleLinearPrivate *priv = goat_scale_linear_get_instance_private (self);
 
 const double step_minor = (priv->major_delta / priv->minors_per_major);
-const int register start = (top - nil) / step_minor / factor;
-const int register end = (bottom - nil) / step_minor / factor;
-g_print ("[] bottom %i top %i _nil %lf\n", bottom, top, nil);
-g_print ("> start=%i end=%i %lf _factor\n", start, end, factor);
-int register i;
+gint register i;
 const gint width_major = priv->width_major;
 const gint width_minor = priv->width_minor;
 GdkRGBA color_minor = priv->color_minor;
@@ -202,8 +202,10 @@ static void draw (GoatScale *scale, cairo_t *cr, gint left, gint right, gint top
 cairo_set_line_width (cr, 1.);
 
 if (where == GOAT_POSITION_LEFT) {
+const int register start = (top - nil) / step_minor / factor;
+const int register end = (bottom - nil) / step_minor / factor;
 for (i = start; i <= end; i++) {
-const gboolean register majorstip = (i % priv->minors_per_major == 0);
+const gboolean register majorstip = is_major_tick (i, priv->minors_per_major);
 const double register y = nil + top + step_minor * factor * i;
 if (grid) {
 cairo_move_to (cr, right, y);
@@ -231,8 +233,10 @@ static void draw (GoatScale *scale, cairo_t *cr, gint left, gint right, gint top
 }
 }
 if (where == GOAT_POSITION_RIGHT) {
+const int register start = (top - nil) / step_minor / factor;
+const int register end = (bottom - nil) / step_minor / factor;
 for (i = start; i <= end; i++) {
-const gboolean register majorstip = (i % priv->minors_per_major == 0);
+const gboolean register majorstip = is_major_tick (i, priv->minors_per_major);
 const double register y = nil + top + step_minor * factor * i;
 if (grid) {
 cairo_move_to (cr, left, y);
@@ -260,8 +264,10 @@ static void draw (GoatScale *scale, cairo_t *cr, gint left, gint right, gint top
 }
 }
 if (where == GOAT_POSITION_BOTTOM) {
+const int register start = (left - nil) / step_minor / factor;
+const int register end = (right - nil) / step_minor / factor;
 for (i = start; i <= end; i++) {
-const gboolean register majorstip = (i % priv->minors_per_major == 0);
+const gboolean register majorstip = is_major_tick (i, priv->minors_per_major);
 const double register x = nil + left + step_minor * factor * i;
 if (grid) {
 cairo_move_to (cr, x, top);
@@ -289,8 +295,10 @@ static void draw (GoatScale *scale, cairo_t *cr, gint left, gint right, gint top
 }
 }
 if (where == GOAT_POSITION_TOP) {
+const int register start = (left - nil) / step_minor / factor;
+const int register end = (right - nil) / step_minor / factor;
 for (i = start; i <= end; i++) {
-const gboolean register majorstip = (i % priv->minors_per_major == 0);
+const gboolean register majorstip = is_major_tick (i, priv->minors_per_major);
 const double register x = nil + left + step_minor * factor * i;
 if (grid) {
 cairo_move_to (cr, x, bottom);

tests/dynamic.c

@@ -38,6 +38,8 @@ int main (int argc, char *argv[])
 GoatScale *scale_x = GOAT_SCALE (goat_scale_linear_new (GOAT_POSITION_BOTTOM, GOAT_ORIENTATION_HORIZONTAL));
 GoatScale *scale_y = GOAT_SCALE (goat_scale_linear_new (GOAT_POSITION_RIGHT, GOAT_ORIENTATION_VERTICAL));
 
+goat_scale_linear_set_ticks (GOAT_SCALE_LINEAR (scale_y), 100, 2);
+
 plot = goat_plot_new (scale_x, scale_y);
 
 GoatDataset *dataset;

tests/screenshot.c

@@ -49,7 +49,7 @@ int main (int argc, char *argv[])
 box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
 scale_x = GOAT_SCALE (goat_scale_linear_new (GOAT_POSITION_TOP, GOAT_ORIENTATION_HORIZONTAL));
 goat_scale_set_range (scale_x, -44., +30.);
-goat_scale_linear_set_ticks (GOAT_SCALE_LINEAR (scale_x), 50, 5);
+goat_scale_linear_set_ticks (GOAT_SCALE_LINEAR (scale_x), 100, 5);
 scale_y = GOAT_SCALE (goat_scale_linear_new (GOAT_POSITION_LEFT, GOAT_ORIENTATION_VERTICAL));
 goat_scale_set_range_auto (scale_y);
 goat_scale_linear_set_ticks (GOAT_SCALE_LINEAR (scale_y), 50, 5);