X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=acre.c;h=8ba639ebf24e5c86321a482c6b9e2482ce3aa6d6;hb=2ede293f10cdbf9267f48823930950d31be83767;hp=0851902c51d3b8e4bd029b81fd9c34c7b4a5594a;hpb=df97f91d034186598ca0f4cb110c90fda4fef09a;p=acre

diff --git a/acre.c b/acre.c
index 0851902..8ba639e 100644
--- a/acre.c
+++ b/acre.c
@@ -90,6 +90,11 @@ acre_create (void)
     acre->data_size = 0;
     acre->num_data = 0;
 
+    acre->chart.x = 0;
+    acre->chart.y = 0;
+    acre->chart.width = 0;
+    acre->chart.height = 0;
+
     return acre;
 }
 
@@ -157,7 +162,11 @@ acre_add_data (acre_t *acre, acre_data_t *data)
 #define ACRE_FONT_SIZE 12
 #define ACRE_TITLE_FONT_SIZE 32
 #define ACRE_PAD (ACRE_FONT_SIZE)
-#define ACRE_TICK_SIZE 6
+#define ACRE_TICK_MAJOR_SIZE 6
+#define ACRE_TICK_MINOR_SIZE 3
+#define ACRE_TICK_MINOR_DIVISIONS 5
+#define ACRE_X_TICK_VALUE_PAD 2
+#define ACRE_Y_TICK_VALUE_PAD 4
 
 static PangoLayout *
 _create_layout (acre_t *acre, const char *text)
@@ -228,6 +237,8 @@ _draw_title_and_labels (acre_t *acre)
     cairo_t *cr = acre->cr;
     PangoFontDescription *title_font;
     PangoLayout *title_layout, *x_axis_layout, *y_axis_layout;
+    PangoLayout *min_y, *max_y;
+    int min_y_width, max_y_width, y_axis_value_width;
     int title_width, title_height;
     int x_axis_width, x_axis_height;
     int y_axis_width, y_axis_height;
@@ -251,14 +262,22 @@ _draw_title_and_labels (acre_t *acre)
     x_axis_layout = _create_layout (acre, acre->x_axis.label);
     y_axis_layout = _create_layout (acre, acre->y_axis.label);
 
+    min_y = _create_layout_printf (acre, "%g",
+				   round (acre->y_axis.min));
+    max_y = _create_layout_printf (acre, "%g",
+				   round (acre->y_axis.max));
+
+    pango_layout_get_pixel_size (min_y, &min_y_width, NULL);
+    pango_layout_get_pixel_size (max_y, &max_y_width, NULL);
+    y_axis_value_width = MAX (min_y_width, max_y_width);
+
+    _destroy_layout (min_y);
+    _destroy_layout (max_y);
+
     /* Iterate with the layout of the title and axis labels until they
      * are stable, (this requires iteration since we don't know what
      * to set their widths to in advance due to the wrapping of the
      * other elements). */
-    acre->chart.x = 0;
-    acre->chart.y = 0;
-    acre->chart.width = acre->width;
-    acre->chart.height = acre->height;
     while (1) {
 	pango_layout_set_width (title_layout, acre->chart.width * PANGO_SCALE);
 	pango_layout_set_width (x_axis_layout, acre->chart.width * PANGO_SCALE);
@@ -269,11 +288,13 @@ _draw_title_and_labels (acre_t *acre)
 	pango_layout_get_pixel_size (y_axis_layout, &y_axis_width, &y_axis_height);
 
 	new_chart.x = ACRE_PAD + y_axis_height +
-	    ACRE_PAD + ACRE_FONT_SIZE;
+	    ACRE_PAD + y_axis_value_width + ACRE_Y_TICK_VALUE_PAD;
 	new_chart.width = acre->width - acre->chart.x - ACRE_PAD;
 
 	new_chart.y = ACRE_PAD + title_height + ACRE_PAD;
-	new_chart.height = acre->height - acre->chart.y - (ACRE_FONT_SIZE + ACRE_PAD + x_axis_height + ACRE_PAD);
+	new_chart.height = acre->height - acre->chart.y - 
+	    (ACRE_X_TICK_VALUE_PAD + ACRE_FONT_SIZE +
+	     ACRE_PAD + x_axis_height + ACRE_PAD);
 
 	if (new_chart.x == acre->chart.x &&
 	    new_chart.y == acre->chart.y &&
@@ -358,7 +379,7 @@ _expand_range_for_width (double *axis_min, double *axis_max, int pixel_size)
     range = *axis_max - *axis_min;
 
     step = _step_for_range (range);
-    pixel_step = step * pixel_size / range;
+    pixel_step = step * pixel_size / range / ACRE_TICK_MINOR_DIVISIONS;
 
     /* We expand the range by the ratio of the pixel step to the floor
      * of the pixel_step.
@@ -395,6 +416,11 @@ _compute_axis_ranges (acre_t *acre)
     double x_adjust, y_adjust;
     cairo_t *cr = acre->cr;
 
+    acre->x_axis.min = acre->data[0]->points[0].x;
+    acre->x_axis.max = acre->data[0]->points[0].x;
+    acre->y_axis.min = acre->data[0]->points[0].y;
+    acre->y_axis.min = acre->data[0]->points[0].y;
+
     /* First, simply find the extrema of the data. */
     for (d = 0; d < acre->num_data; d++) {
 	data = acre->data[d];
@@ -478,94 +504,103 @@ _draw_data (acre_t *acre)
     cairo_restore (cr);
 }
 
+typedef enum _ticks { ACRE_TICKS_X, ACRE_TICKS_Y } acre_ticks_t;
+
 static void
-_draw_frame_and_ticks (acre_t *acre)
+_draw_ticks (acre_t *acre,
+	     double axis_min, double axis_max,
+	     acre_ticks_t ticks)
 {
     cairo_t *cr = acre->cr;
-    double step, x, y;
+    double t, step, sub_step;
 
     cairo_save (cr);
 
-    cairo_set_source_rgb (cr, 0, 0, 0); /* black */
+    _set_transform_to_data_space (acre);
 
-    /* First the ticks within data space. */
-    cairo_save (cr);
+    step = _step_for_range (axis_max - axis_min);
+    sub_step = step / ACRE_TICK_MINOR_DIVISIONS;
+
+    for (t = (floor (axis_min / sub_step) + 1) * sub_step;
+	 t <= axis_max;
+	 t += sub_step)
     {
-	_set_transform_to_data_space (acre);
+	int tick_size;
+	if (fabs((t / step) - (int) (t / step)) < 0.5 * (sub_step / step))
+	    tick_size = ACRE_TICK_MAJOR_SIZE;
+	else
+	    tick_size = ACRE_TICK_MINOR_SIZE;
 
-	step = _step_for_range (acre->x_axis.max -acre->x_axis.min);
-	x = (floor (acre->x_axis.min / step) + 1) * step;
-	while (x <= acre->x_axis.max) {
-	    cairo_move_to (cr, x, acre->y_axis.min);
-	    cairo_save (cr);
-	    {
-		/* tick */
-		cairo_save (cr);
-		{
-		    cairo_identity_matrix (cr);
-		    cairo_rel_line_to (cr, 0, 0.5);
-		    cairo_rel_line_to (cr, 0, -ACRE_TICK_SIZE-0.5);
-		    cairo_set_line_width (cr, 1.0);
-		    cairo_stroke (cr);
-		}
-		cairo_restore (cr);
-
-		/* label */
-		cairo_save (cr);
-		{
-		    PangoLayout *layout;
-		    int width, height;
-		    layout = _create_layout_printf (acre, "%g", x);
-		    cairo_move_to (cr, x, acre->y_axis.min);
-		    cairo_identity_matrix (cr);
-		    pango_layout_get_pixel_size (layout, &width, &height);
-		    cairo_rel_move_to (cr, -width / 2, 2);
-		    _show_layout (cr, layout);
-		}
-		cairo_restore (cr);
+	/* tick */
+	cairo_save (cr);
+	{
+	    if (ticks == ACRE_TICKS_X)
+		cairo_move_to (cr, t, acre->y_axis.min);
+	    else
+		cairo_move_to (cr, acre->x_axis.min, t);
+
+	    cairo_identity_matrix (cr);
+
+	    if (ticks == ACRE_TICKS_X) {
+		cairo_rel_line_to (cr, 0, 0.5);
+		cairo_rel_line_to (cr, 0, -tick_size - 0.5);
+	    } else {
+		cairo_rel_line_to (cr, -0.5, 0);
+		cairo_rel_line_to (cr, tick_size + 0.5, 0);
 	    }
-	    cairo_restore (cr);
-	    x += step;
+
+	    cairo_set_line_width (cr, 1.0);
+	    cairo_stroke (cr);
 	}
+	cairo_restore (cr);
+
+	/* label */
+	if (tick_size == ACRE_TICK_MAJOR_SIZE)
+	{
+	    PangoLayout *layout;
+	    int width, height;
 
-	step = _step_for_range (acre->y_axis.max -acre->y_axis.min);
-	y = (floor (acre->y_axis.min / step) + 1) * step;
-	while (y <= acre->y_axis.max) {
-	    cairo_move_to (cr, acre->x_axis.min, y);
 	    cairo_save (cr);
-	    {
-		/* tick */
-		cairo_save (cr);
-		{
-		    cairo_identity_matrix (cr);
-		    cairo_rel_line_to (cr, -0.5, 0);
-		    cairo_rel_line_to (cr, ACRE_TICK_SIZE+0.5, 0);
-		    cairo_set_line_width (cr, 1.0);
-		    cairo_stroke (cr);
-		}
-		cairo_restore (cr);
-
-		/* label */
-		cairo_save (cr);
-		{
-		    PangoLayout *layout;
-		    int width, height;
-		    layout = _create_layout_printf (acre, "%g", y);
-		    cairo_move_to (cr, acre->x_axis.min, y);
-		    cairo_identity_matrix (cr);
-		    pango_layout_get_pixel_size (layout, &width, &height);
-		    cairo_rel_move_to (cr, -width-2, -height/2);
-		    _show_layout (cr, layout);
-		}
-		cairo_restore (cr);
-	    }
+
+	    layout = _create_layout_printf (acre, "%g", t);
+
+	    if (ticks == ACRE_TICKS_X)
+		cairo_move_to (cr, t, acre->y_axis.min);
+	    else
+		cairo_move_to (cr, acre->x_axis.min, t);
+
+	    cairo_identity_matrix (cr);
+	    pango_layout_get_pixel_size (layout, &width, &height);
+
+	    if (ticks == ACRE_TICKS_X)
+		cairo_rel_move_to (cr, -width / 2, ACRE_X_TICK_VALUE_PAD);
+	    else
+		cairo_rel_move_to (cr, -width - ACRE_Y_TICK_VALUE_PAD,
+				   -height/2);
+
+	    _show_layout (cr, layout);
+
 	    cairo_restore (cr);
-	    y += step;
 	}
     }
+
     cairo_restore (cr);
+}
 
-    /* Then the frame drawn in pixel space. */
+static void
+_draw_frame_and_ticks (acre_t *acre)
+{
+    cairo_t *cr = acre->cr;
+
+    cairo_save (cr);
+
+    cairo_set_source_rgb (cr, 0, 0, 0); /* black */
+
+    /* ticks */
+    _draw_ticks (acre, acre->x_axis.min, acre->x_axis.max, ACRE_TICKS_X);
+    _draw_ticks (acre, acre->y_axis.min, acre->y_axis.max, ACRE_TICKS_Y);
+
+    /* frame */
     cairo_rectangle (cr,
 		     acre->chart.x - 0.5, acre->chart.y - 0.5,
 		     acre->chart.width + 1.0, acre->chart.height + 1.0);
@@ -584,17 +619,25 @@ void
 acre_draw (acre_t *acre, cairo_t *cr, int width, int height)
 {
     acre->cr = cr;
+
     acre->width = width;
     acre->height = height;
 
+    acre->chart.width = width;
+    acre->chart.height = height;
+
     cairo_save (cr);
 
     cairo_set_source_rgb (cr, 1, 1, 1);
 
-    cairo_paint (cr);
+    /* We compute the axis ranges before doing label layout so that we
+     * can account for the width of the y-axis value labels. */
+    _compute_axis_ranges (acre);
 
     _draw_title_and_labels (acre);
 
+    /* And we recompute the axis ranges now that the title and axis
+     * label space is all measured and accounted for. */
     _compute_axis_ranges (acre);
 
     _draw_data (acre);