X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=acre.c;h=1b238fdb33babc5471f818e886b9b708ca9790f0;hb=3651b8c6038a7414e088d4263f67bf6efd87d2bd;hp=6d1262abe0af95f72864255d0781c688d3bf65fd;hpb=bdcec99e706ccb2af0600bce67b7ade6e0abf348;p=acre diff --git a/acre.c b/acre.c index 6d1262a..1b238fd 100644 --- a/acre.c +++ b/acre.c @@ -19,6 +19,7 @@ #define _ISOC99_SOURCE /* for round() */ #define _XOPEN_SOURCE 500 +#define _GNU_SOURCE /* for asprintf() */ #include "acre.h" #include "xmalloc.h" @@ -56,6 +57,7 @@ struct _acre { /* Data for drawing. */ cairo_t *cr; + PangoFontDescription *font; /* Total size including labels. */ int width; @@ -156,11 +158,38 @@ acre_add_data (acre_t *acre, acre_data_t *data) #define ACRE_PAD (ACRE_FONT_SIZE) #define ACRE_TICK_SIZE 6 +static PangoLayout * +_create_layout (acre_t *acre, const char *text) +{ + PangoLayout *layout; + + layout = pango_cairo_create_layout (acre->cr); + pango_layout_set_font_description (layout, acre->font); + pango_layout_set_text (layout, text, -1); + pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER); + + return layout; +} + +static void +_destroy_layout (PangoLayout *layout) +{ + g_object_unref (layout); +} + +static void +_show_layout (cairo_t *cr, PangoLayout *layout) +{ + pango_cairo_show_layout (cr, layout); + + _destroy_layout (layout); +} + static void _draw_title_and_labels (acre_t *acre) { cairo_t *cr = acre->cr; - PangoFontDescription *acre_font, *title_font; + PangoFontDescription *title_font; PangoLayout *title_layout, *x_axis_layout, *y_axis_layout; int title_width, title_height; int x_axis_width, x_axis_height; @@ -169,9 +198,9 @@ _draw_title_and_labels (acre_t *acre) cairo_save (cr); - acre_font = pango_font_description_new (); - pango_font_description_set_family (acre_font, ACRE_FONT_FAMILY); - pango_font_description_set_absolute_size (acre_font, + acre->font = pango_font_description_new (); + pango_font_description_set_family (acre->font, ACRE_FONT_FAMILY); + pango_font_description_set_absolute_size (acre->font, ACRE_FONT_SIZE * PANGO_SCALE); title_font = pango_font_description_new (); @@ -179,20 +208,11 @@ _draw_title_and_labels (acre_t *acre) pango_font_description_set_absolute_size (title_font, ACRE_TITLE_FONT_SIZE * PANGO_SCALE); - title_layout = pango_cairo_create_layout (cr); + title_layout = _create_layout (acre, acre->title); pango_layout_set_font_description (title_layout, title_font); - pango_layout_set_text (title_layout, acre->title, -1); - pango_layout_set_alignment (title_layout, PANGO_ALIGN_CENTER); - - x_axis_layout = pango_cairo_create_layout (cr); - pango_layout_set_font_description (x_axis_layout, acre_font); - pango_layout_set_text (x_axis_layout, acre->x_axis.label, -1); - pango_layout_set_alignment (x_axis_layout, PANGO_ALIGN_CENTER); - y_axis_layout = pango_cairo_create_layout (cr); - pango_layout_set_font_description (y_axis_layout, acre_font); - pango_layout_set_text (y_axis_layout, acre->y_axis.label, -1); - pango_layout_set_alignment (y_axis_layout, PANGO_ALIGN_CENTER); + x_axis_layout = _create_layout (acre, acre->x_axis.label); + y_axis_layout = _create_layout (acre, acre->y_axis.label); /* Iterate with the layout of the title and axis labels until they * are stable, (this requires iteration since we don't know what @@ -235,21 +255,21 @@ _draw_title_and_labels (acre_t *acre) cairo_set_source_rgb (cr, 0, 0, 0); cairo_move_to (cr, acre->chart.x, ACRE_PAD); - pango_cairo_show_layout (cr, title_layout); + _show_layout (cr, title_layout); cairo_save (cr); { cairo_translate (cr, ACRE_PAD, acre->chart.y + acre->chart.height); cairo_rotate (cr, - M_PI / 2.0); cairo_move_to (cr, 0, 0); - pango_cairo_show_layout (cr, y_axis_layout); + _show_layout (cr, y_axis_layout); } cairo_restore (cr); cairo_move_to (cr, acre->chart.x, acre->chart.y + acre->chart.height + ACRE_FONT_SIZE + ACRE_PAD); - pango_cairo_show_layout (cr, x_axis_layout); + _show_layout (cr, x_axis_layout); cairo_restore (cr); } @@ -293,18 +313,24 @@ _step_for_range (double range) * amount for the major ticks (see _step_for_range). To get * nice-looking pixel-snapped ticks we want to expand the range * slightly. */ -static double -_expand_range (double data_range, int pixel_size) +static void +_expand_range_for_width (double *axis_min, double *axis_max, int pixel_size) { - double step, pixel_step; + double range, new_range, step, pixel_step; + + range = *axis_max - *axis_min; - step = _step_for_range (data_range); - pixel_step = step * pixel_size / data_range; + step = _step_for_range (range); + pixel_step = step * pixel_size / range; /* We expand the range by the ratio of the pixel step to the floor * of the pixel_step. */ - return data_range * pixel_step / floor (pixel_step); + new_range = range * pixel_step / floor (pixel_step); + + /* And spread the increase out on either side of the range. */ + *axis_min -= (new_range - range) / 2.0; + *axis_max += (new_range - range) / 2.0; } /* Setup a transformation in acre->cr such that data values plotted @@ -329,8 +355,7 @@ _compute_axis_ranges (acre_t *acre) { unsigned int d, i; acre_data_t *data; - double x_range, new_x_range, x_adjust; - double y_range, new_y_range, y_adjust; + double x_adjust, y_adjust; cairo_t *cr = acre->cr; /* First, simply find the extrema of the data. */ @@ -352,18 +377,13 @@ _compute_axis_ranges (acre_t *acre) /* Next, increase the axis ranges just enough so that the step * sizes for the ticks will be integers. */ - x_range = acre->x_axis.max - acre->x_axis.min; - new_x_range = _expand_range (x_range, acre->chart.width); - - y_range = acre->y_axis.max - acre->y_axis.min; - new_y_range = _expand_range (y_range, acre->chart.height); - - /* And spread the increase out on either side of the range. */ - acre->x_axis.min -= (new_x_range - x_range) / 2.0; - acre->x_axis.max += (new_x_range - x_range) / 2.0; + _expand_range_for_width (&acre->x_axis.min, + &acre->x_axis.max, + acre->chart.width); - acre->y_axis.min -= (new_y_range - y_range) / 2.0; - acre->y_axis.max += (new_y_range - y_range) / 2.0; + _expand_range_for_width (&acre->y_axis.min, + &acre->y_axis.max, + acre->chart.height); /* Finally, we also translate the axis ranges slightly so that the * ticks land on half-integer device-pixel positions. @@ -442,11 +462,33 @@ _draw_frame_and_ticks (acre_t *acre) cairo_move_to (cr, x, acre->y_axis.min); 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); + /* 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; + char *label; + int width, height; + asprintf (&label, "%g", x); + layout = _create_layout (acre, label); + free (label); + 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); } cairo_restore (cr); x += step; @@ -458,11 +500,33 @@ _draw_frame_and_ticks (acre_t *acre) cairo_move_to (cr, acre->x_axis.min, y); 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); + /* 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; + char *label; + int width, height; + asprintf (&label, "%g", y); + layout = _create_layout (acre, label); + free (label); + 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); } cairo_restore (cr); y += step;