X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=acre.c;h=12be71d249952421f0fb17caa956e3cd74377a0f;hb=af6a6a5cafbbbbb1d5e1cffcab4c5903853d9758;hp=908bebd74fb15a2921205138f20e19100347b4d9;hpb=3812d8a3fc2e73e9a3ae87b748df69ce9b59a90a;p=acre diff --git a/acre.c b/acre.c index 908bebd..12be71d 100644 --- a/acre.c +++ b/acre.c @@ -160,9 +160,12 @@ 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 static PangoLayout * _create_layout (acre_t *acre, const char *text) @@ -284,11 +287,13 @@ _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 + y_axis_value_width; + 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 && @@ -329,7 +334,7 @@ _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; @@ -345,15 +350,21 @@ _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 @@ -366,14 +377,17 @@ _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. @@ -431,7 +445,24 @@ _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, @@ -471,6 +502,16 @@ _draw_data (acre_t *acre) cairo_t *cr = acre->cr; unsigned int d, i; acre_data_t *data; +#define NUM_COLORS 3 + struct { + double r; + double g; + double b; + } colors [NUM_COLORS] = { + {1, 0, 0}, + {0, 1, 0}, + {0, 0, 1} + }; cairo_save (cr); @@ -479,6 +520,11 @@ _draw_data (acre_t *acre) _set_transform_to_data_space (acre); for (d = 0; d < acre->num_data; d++) { + int color = d % NUM_COLORS; + cairo_set_source_rgb (cr, + colors[color].r, + colors[color].g, + colors[color].b); data = acre->data[d]; cairo_new_path (cr); for (i = 0; i < data->num_points; i++) { @@ -498,94 +544,104 @@ _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; - 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-4, -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_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); - /* Then the frame drawn in pixel space. */ + /* frame */ cairo_rectangle (cr, acre->chart.x - 0.5, acre->chart.y - 0.5, acre->chart.width + 1.0, acre->chart.height + 1.0);