** at http://gnomejournal.org/article/34/writing-a-widget-using-cairo-and-gtk28
** Started on Thu Jul 17 10:51:32 2008 Johnny Q. Hacker
-** Last update Sun May 12 01:17:25 2002 Speed Blue
+** Last update Thu Oct 8 17:13:50 2009 Johnny Q. Hacker
*/
#include <graphwidget.h>
G_DEFINE_TYPE(GraphWidget, graph_widget, GTK_TYPE_DRAWING_AREA);
#define INSET_PERCENT 0.1
-#define TITLE_PERCENT 0.1
+#define TITLE_PERCENT 0.15
#define DEBUG_DRAW_AXIS
struct drawing_context {
GtkWidget *widget;
cairo_t *cr;
double radius;
+ double xoffset;
+ double yoffset;
+ double xscaling;
+ double yscaling;
+ /*Semi-normalized maxima*/
double xmax;
double ymax;
cairo_matrix_t data_scale;
static void draw_point(gpointer data, gpointer user_data) {
struct drawing_context *cxt = user_data;
struct graph_point *pt = data;
- cairo_save(cxt->cr);
- cairo_transform(cxt->cr, cxt->data_xlat);
- cairo_transform(cxt->cr, cxt->data_scale);
- double x = pt->x;
- double y = pt->y;
+ double x = (pt->x + cxt->xoffset)*cxt->xscaling;
+ double y = (pt->y + cxt->yoffset)*cxt->yscaling;
cairo_move_to(cxt->cr, x, y);
cairo_arc(cxt->cr, x, y, cxt->radius, 0, 2*M_PI);
if(pt->label != NULL) {
cairo_show_text(cxt->cr, pt->label->str);
cairo_restore(cxt->cr);
}
- cairo_restore;
}
static void draw_lines(gpointer data, gpointer user_data) {
struct drawing_context *cxt = user_data;
struct graph_line *l = data;
- cairo_save(cxt->cr);
- cairo_transform(cxt->cr, cxt->data_xlat);
- cairo_transform(cxt->cr, cxt->data_scale);
- double p0_x = l->p0_x;
- double p0_y = l->p0_y;
- double p1_x = l->p1_x;
- double p1_y = l->p1_y;
- double p2_x = l->p2_x;
- double p2_y = l->p2_y;
- double p3_x = l->p3_x;
- double p3_y = l->p3_y;
+ double p0_x = (l->p0_x + cxt->xoffset)*cxt->xscaling;
+ double p0_y = (l->p0_y + cxt->yoffset)*cxt->yscaling;
+ double p1_x = (l->p1_x + cxt->xoffset)*cxt->xscaling;
+ double p1_y = (l->p1_y + cxt->yoffset)*cxt->yscaling;
+ double p2_x = (l->p2_x + cxt->xoffset)*cxt->xscaling;
+ double p2_y = (l->p2_y + cxt->yoffset)*cxt->yscaling;
+ double p3_x = (l->p3_x + cxt->xoffset)*cxt->xscaling;
+ double p3_y = (l->p3_y + cxt->yoffset)*cxt->yscaling;
#ifdef DEBUG_DRAW
fprintf(stderr, "draw_lines: p0_x=%g, p0_y=%g, p1_x=%g, p1_y=%g, p2_x=%g, p2_y=%g, p3_x=%g, p3_y=%g\n", p0_x, p0_y, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
#endif
cairo_move_to(cxt->cr, p0_x, p0_y);
cairo_curve_to(cxt->cr, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
- cairo_restore(cxt->cr);
}
-static void draw_axis(struct drawing_context* cxt, struct graph_axis *axis) {
- cairo_save(cxt->cr);
- cairo_transform(cxt->cr, cxt->data_xlat);
- cairo_transform(cxt->cr, cxt->data_scale);
+static void draw_axis(struct drawing_context* cxt, struct graph_axis *axis, double scaling, double offset, double max) {
#ifdef DEBUG_DRAW_AXIS
fprintf(stderr, "draw_axis; major_start=%g, major_step=%g, >major=%d, minor=%d, subminor=%d, label=%s\n", axis->major_start, axis->major_step, axis->major, axis->minor, axis->subminor, axis->title->str);
#endif
cairo_move_to(cxt->cr, 0, 0);
- cairo_line_to(cxt->cr, 1, 0);
+ cairo_line_to(cxt->cr, max, 0);
register int i, j, k;
register double pos, mpos, smpos;
for(i=0; i<axis->major; i++) {
pos=i*axis->major_step + axis->major_start;
cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
- cairo_restore(cxt->cr);
}
static void draw(GtkWidget *graph, cairo_t *cr) {
axis_inset = ((effective_height > effective_width)?effective_width:effective_height)*TITLE_PERCENT;
effective_height -= axis_inset;
effective_width -= axis_inset;
- }elsif(gw->graph->xaxis != NULL) {
+ }else if(gw->graph->xaxis != NULL) {
effective_height -= effective_height*TITLE_PERCENT;
- }elsif(gw->graph->yaxis != NULL) {
+ }else if(gw->graph->yaxis != NULL) {
effective_width -= effective_width*TITLE_PERCENT;
}
if(effective_width > effective_height) {
double yscaling = (gw->graph->points->len == 1)? cxt.ymax : (cxt.ymax/(maxy-miny));
double xoffset = (gw->graph->points->len == 1)? (-minx/2) : (-minx);
double yoffset = (gw->graph->points->len == 1)? (-miny/2) : (-miny);
+ /*Finish up our context information.*/
+ cxt.xscaling = (gw->graph->points->len == 1)? cxt.xmax : (cxt.xmax/(((maxx - minx)==0)?1:(maxx-minx)));
+ cxt.yscaling = (gw->graph->points->len == 1)? cxt.ymax : (cxt.ymax/(((maxy - miny)==0)?1:(maxy-miny)));
+ cxt.xoffset = (gw->graph->points->len == 1)? (-minx/2) : (-minx);
+ cxt.yoffset = (gw->graph->points->len == 1)? (-miny/2) : (-miny);
cairo_matrix_translate(&(cxt.data_xlat), xoffset, yoffset);
cairo_matrix_scale(&(cxt.data_scale), xscaling, yscaling);
+ #ifdef DEBUG
+ fprintf(stderr, "minx=%g, maxx=%g, miny=%g, maxy=%g, xscaling=%g, yscaling=%g, xoffset=%g, yoffset=%g\n", minx, maxx, miny, maxy, cxt.xscaling, cxt.yscaling, cxt.xoffset, cxt.yoffset);
+ fprintf(stderr, "x0=%g, y0=%g, width=%g, height=%g\n", x0, y0, height, width);
+ fprintf(stderr, "translate=(%g, %g)\n", x0 + ((width>height)?(width-height)/2.0:0), y0+((width > height)?height:width) + ((height>width)?(height-width)/2.0:0));
+ #endif
+ double offset_height = ((width>=height)?height*INSET_PERCENT:0);;
+ double offset_width = ((height>=width)?width*INSET_PERCENT:0);
+ double inset_height = height - offset_height;
+ double inset_width = width - offset_width;
cairo_save(cr);
- cairo_translate(cr, effective_width - inset/2, effective_height - inset/2);
- cairo_scale(cr, effective_width, effective_height);
+ cairo_translate(cr, x0 + (width - effective_width) - inset/2, y0 + effective_height + inset/2);
+ cairo_scale(cr, effective_width/cxt.xmax, -effective_height/cxt.ymax);
cairo_set_line_width(cr, 0.005);
- cairo_select_font_face (cr, "Sans Serif",
+ cairo_select_font_face (cr, "Georgia",
CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
cairo_set_font_size (cr, 0.05);
if(gw->graph->lines != NULL) {
cairo_set_source_rgb(cr, 0, 0, 0);
g_ptr_array_foreach(gw->graph->points, &draw_point, (gpointer)&cxt);
if(gw->graph->xaxis != NULL)
- draw_axis(&cxt, gw->graph->xaxis, cxt.xscaling, cxt.xoffset);
+ draw_axis(&cxt, gw->graph->xaxis, cxt.xscaling, cxt.xoffset, cxt.xmax);
if(gw->graph->yaxis != NULL) {
cairo_save(cr);
cairo_matrix_t matrix = { .xx=0, .xy = 1, .x0 = 0, .yx = 1, .yy = 0, .y0 = 0 };
cairo_transform(cr, &matrix);
- draw_axis(&cxt, gw->graph->yaxis, cxt.yscaling, cxt.yoffset);
+ draw_axis(&cxt, gw->graph->yaxis, cxt.yscaling, cxt.yoffset, cxt.ymax);
cairo_restore(cr);
}
cairo_stroke(cr);
projects / scdataviz / blobdiff