X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=acre.c;h=35d0541d9c4b14bc58eef0da4d86bc61121be27a;hb=4df04fc13a5b7411dbdba561528e18f234a5364d;hp=1b238fdb33babc5471f818e886b9b708ca9790f0;hpb=3651b8c6038a7414e088d4263f67bf6efd87d2bd;p=acre diff --git a/acre.c b/acre.c index 1b238fd..35d0541 100644 --- a/acre.c +++ b/acre.c @@ -25,6 +25,7 @@ #include "xmalloc.h" #include +#include #include typedef struct _acre_data_point_2d { @@ -58,6 +59,8 @@ struct _acre { /* Data for drawing. */ cairo_t *cr; PangoFontDescription *font; + struct { double r; double g; double b;} colors[3]; + int num_colors; /* Total size including labels. */ int width; @@ -89,6 +92,11 @@ 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; } @@ -154,9 +162,14 @@ acre_add_data (acre_t *acre, acre_data_t *data) #define ACRE_FONT_FAMILY "sans" #define ACRE_FONT_SIZE 12 -#define ACRE_TITLE_FONT_SIZE 32 +#define ACRE_TITLE_FONT_SIZE 20 #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_X_TICK_VALUE_PAD 2 +#define ACRE_Y_TICK_VALUE_PAD 4 +#define ACRE_LEGEND_PAD 4 +#define ACRE_LEGEND_LINE_SIZE 10 static PangoLayout * _create_layout (acre_t *acre, const char *text) @@ -171,6 +184,42 @@ _create_layout (acre_t *acre, const char *text) return layout; } +#define PRINTF_FORMAT(fmt_index, va_index) __attribute__ ((__format__(__printf__, fmt_index, va_index))) + +static PangoLayout * +_create_layout_vprintf (acre_t *acre, const char *fmt, va_list ap) +{ + PangoLayout *layout; + char *text; + + vasprintf (&text, fmt, ap); + + layout = _create_layout (acre, text); + + free (text); + + return layout; +} + +static PangoLayout * +_create_layout_printf (acre_t *acre, const char *fmt, ...) + PRINTF_FORMAT (2, 3); + +static PangoLayout * +_create_layout_printf (acre_t *acre, const char *fmt, ...) +{ + va_list ap; + PangoLayout *layout; + + va_start (ap, fmt); + + layout = _create_layout_vprintf (acre, fmt, ap); + + va_end (ap); + + return layout; +} + static void _destroy_layout (PangoLayout *layout) { @@ -191,6 +240,8 @@ _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; @@ -214,14 +265,22 @@ _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); @@ -232,11 +291,13 @@ _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 && @@ -277,7 +338,7 @@ _draw_title_and_labels (acre_t *acre) /* For a given axis range, compute a step size (in data space) to * generate a suitable number of ticks (5 or so). */ static double -_step_for_range (double range) +_step_for_range (double range, int *minor_divisions) { double step, scale_factor; @@ -293,15 +354,21 @@ _step_for_range (double range) * 10). The threshold values between these are computed * logarithmically. */ if (step < 3.535533905932738) { - if (step < 1.58113883008419) + if (step < 1.58113883008419) { step = 1.0; - else + *minor_divisions = 4; + } else { step = 2.5; + *minor_divisions = 5; + } } else { - if (step < 7.071067811865475) + if (step < 7.071067811865475) { step = 5.0; - else + *minor_divisions = 5; + } else { step = 10.0; + *minor_divisions = 4; + } } /* Un-normalize and we now have the data value that we want to @@ -314,14 +381,17 @@ _step_for_range (double range) * nice-looking pixel-snapped ticks we want to expand the range * slightly. */ static void -_expand_range_for_width (double *axis_min, double *axis_max, int pixel_size) +_expand_range_for_width (double *axis_min, double *axis_max, int pixel_range) { - double range, new_range, step, pixel_step; + double range, new_range, step, step_minor, pixel_step; + int minor_divisions; range = *axis_max - *axis_min; - step = _step_for_range (range); - pixel_step = step * pixel_size / range; + step = _step_for_range (range, &minor_divisions); + step_minor = step / minor_divisions; + + pixel_step = step_minor * (pixel_range / range); /* We expand the range by the ratio of the pixel step to the floor * of the pixel_step. @@ -358,6 +428,11 @@ _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]; @@ -374,7 +449,24 @@ _compute_axis_ranges (acre_t *acre) } } - /* Next, increase the axis ranges just enough so that the step + /* Next, we want to ensure that the data never collides with the + * ticks. So we expand each axis on its minimum side as needed. */ + cairo_save (cr); + { + double x, y; + + _set_transform_to_data_space (acre); + + x = ACRE_TICK_MAJOR_SIZE + 2.0; + y = ACRE_TICK_MAJOR_SIZE + 2.0; + cairo_device_to_user_distance (cr, &x, &y); + + acre->x_axis.min -= x; + acre->y_axis.min += y; + } + cairo_restore (cr); + + /* Then, increase the axis ranges just enough so that the step * sizes for the ticks will be integers. */ _expand_range_for_width (&acre->x_axis.min, @@ -408,6 +500,26 @@ _compute_axis_ranges (acre_t *acre) cairo_restore (cr); } +static void +_choose_colors (acre_t *acre) +{ + /* XXX: Should choose N, equally-spaced colors from a perceptually + * linear space here. */ + acre->num_colors = 3; + + acre->colors[0].r = 1; + acre->colors[0].g = 0; + acre->colors[0].b = 0; + + acre->colors[1].r = 0; + acre->colors[1].g = 1; + acre->colors[1].b = 0; + + acre->colors[2].r = 0; + acre->colors[2].g = 0; + acre->colors[2].b = 1; +} + static void _draw_data (acre_t *acre) { @@ -422,6 +534,11 @@ _draw_data (acre_t *acre) _set_transform_to_data_space (acre); for (d = 0; d < acre->num_data; d++) { + int color = d % acre->num_colors; + cairo_set_source_rgb (cr, + acre->colors[color].r, + acre->colors[color].g, + acre->colors[color].b); data = acre->data[d]; cairo_new_path (cr); for (i = 0; i < data->num_points; i++) { @@ -441,100 +558,161 @@ _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; + int minor_divisions; 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, &minor_divisions); + sub_step = step / 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) - round (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; - 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); + /* 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; - 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); - } + + 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); +} + +static void +_draw_legend (acre_t *acre) +{ + PangoLayout *layout; + int label_width, max_label_width = 0; + int width, height; + unsigned int i; + cairo_t *cr = acre->cr; + + cairo_save (cr); + + for (i = 0; i < acre->num_data; i++) { + layout = _create_layout (acre, acre->data[i]->name); + pango_layout_get_pixel_size (layout, &label_width, NULL); + _destroy_layout (layout); + if (label_width > max_label_width) + max_label_width = label_width; + } + + width = ACRE_LEGEND_PAD + ACRE_LEGEND_LINE_SIZE + ACRE_LEGEND_PAD + + max_label_width + ACRE_LEGEND_PAD; + height = ACRE_LEGEND_PAD + + acre->num_data * (ACRE_FONT_SIZE + ACRE_LEGEND_PAD); + + cairo_translate (cr, acre->chart.x, acre->chart.y); + + cairo_translate (cr, + acre->chart.width - ACRE_LEGEND_PAD - width, + ACRE_LEGEND_PAD); + + cairo_rectangle (cr, -0.5, -0.5, width + 1.0, height + 1.0); + cairo_set_source_rgb (cr, 0, 0, 0); + cairo_set_line_width (cr, 1.0); + cairo_stroke (cr); + + cairo_translate (cr, ACRE_LEGEND_PAD, ACRE_LEGEND_PAD); + + for (i = 0; i < acre->num_data; i++) { + cairo_move_to (cr, 0, ACRE_FONT_SIZE / 2 + 0.5); + cairo_rel_line_to (cr, ACRE_LEGEND_LINE_SIZE, 0); + cairo_set_source_rgb (cr, + acre->colors[i % acre->num_colors].r, + acre->colors[i % acre->num_colors].g, + acre->colors[i % acre->num_colors].b); + cairo_stroke (cr); + + layout = _create_layout (acre, acre->data[i]->name); + cairo_move_to (cr, ACRE_LEGEND_LINE_SIZE + ACRE_LEGEND_PAD, 0); + cairo_set_source_rgb (cr, 0, 0, 0); + _show_layout (cr, layout); + + cairo_translate (cr, 0, ACRE_LEGEND_PAD + ACRE_FONT_SIZE); + } + 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); @@ -553,21 +731,34 @@ 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); + _choose_colors (acre); + + /* 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); + if (acre->num_data > 1) + _draw_legend (acre); + _draw_frame_and_ticks (acre); }