** 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 0.15
+#define DEBUG_DRAW_AXIS
+
struct drawing_context {
GtkWidget *widget;
cairo_t *cr;
double yoffset;
double xscaling;
double yscaling;
+ /*Semi-normalized maxima*/
+ double xmax;
+ double ymax;
+ cairo_matrix_t data_scale;
+ cairo_matrix_t data_xlat;
};
static void draw_point(gpointer data, gpointer user_data) {
- struct drawing_context *cxt = (struct drawing_context *) user_data;
- double *d = (double*)data;
- fprintf(stderr, "draw_point(x=%g(%g) y=%g(%g)) xscaling=%g yscaling=%g xoffset=%g yoffset=%g\n", d[0], (d[0] + cxt->xoffset)*cxt->xscaling, d[1], (d[1] + cxt->yoffset)*cxt->yscaling, cxt->xscaling, cxt->yscaling, cxt->xoffset, cxt->yoffset);
- cairo_arc(cxt->cr, (d[0] + cxt->xoffset)*cxt->xscaling, (d[1] + cxt->yoffset)*cxt->yscaling, cxt->radius, 0, 2*M_PI);
- cairo_set_source_rgb(cxt->cr, 1, 1, 1);
- cairo_fill_preserve(cxt->cr);
- cairo_set_source_rgb(cxt->cr, 0, 0, 0);
- cairo_stroke(cxt->cr);
+ struct drawing_context *cxt = user_data;
+ struct graph_point *pt = data;
+ 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_save(cxt->cr);
+ cairo_scale(cxt->cr, 1, -1);
+ cairo_show_text(cxt->cr, pt->label->str);
+ cairo_restore(cxt->cr);
+ }
+}
+
+static void draw_lines(gpointer data, gpointer user_data) {
+ struct drawing_context *cxt = user_data;
+ struct graph_line *l = data;
+ 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);
+}
+
+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, 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);
+ for(k=0; k<axis->subminor; k++) {
+ smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + pos;
+ cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
+ cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
+ }
+ for(j=0; j<axis->minor; j++) {
+ mpos=(j+1)*(axis->major_step/(axis->minor+1)) + pos;
+ cairo_move_to(cxt->cr, (mpos + offset)*scaling, 0);
+ cairo_line_to(cxt->cr, (mpos + offset)*scaling, 0.025);
+ for(k=0; k<axis->subminor; k++) {
+ smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + mpos;
+ cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
+ cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
+ }
+ }
+ }
+ 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);
}
static void draw(GtkWidget *graph, cairo_t *cr) {
struct drawing_context cxt;
GraphWidget *gw = GRAPH_WIDGET(graph);
- #ifdef DEBUG
- fprintf(stderr, "draw(%d, %d)\n", graph, cr);
+ #ifdef DEBUG_DRAW
+ fprintf(stderr, "draw(%d, %d)\n", (int)graph, (int)cr);
fprintf(stderr, "allocation.x=%d, allocation.y=%d, allocation.height=%d, allocation.width=%d\n", graph->allocation.x, graph->allocation.y, graph->allocation.height, graph->allocation.width);
#endif
double x0=graph->allocation.x;
double y0=graph->allocation.y;
double height=graph->allocation.height;
double width=graph->allocation.width;
+ double minx = gw->graph->minx;
+ double maxx = gw->graph->maxx;
+ double miny = gw->graph->miny;
+ double maxy = gw->graph->maxy;
+ if(gw->graph->xaxis != NULL) {
+ minx = gw->graph->xaxis->major_start;
+ maxx = gw->graph->xaxis->major_start + gw->graph->xaxis->major_step*gw->graph->xaxis->major;
+ }
+ if(gw->graph->yaxis != NULL) {
+ miny = gw->graph->yaxis->major_start;
+ maxy = gw->graph->yaxis->major_start + gw->graph->yaxis->major_step*gw->graph->yaxis->major;
+ }
cxt.widget = graph;
cxt.cr = cr;
- cxt.radius = 0.1;
- cxt.xscaling = (gw->graph->points->len == 1)? 1 : (1/(gw->graph->maxx - gw->graph->minx));
- cxt.yscaling = (gw->graph->points->len == 1)? 1 : (1/(gw->graph->maxy - gw->graph->miny));
- cxt.xoffset = (gw->graph->points->len == 1)? (-gw->graph->minx/2) : (-gw->graph->minx);
- cxt.yoffset = (gw->graph->points->len == 1)? (-gw->graph->miny/2) : (-gw->graph->miny);
+ cxt.radius = 0.01;
+ /*Set up our semi-normalized scaling. The shortest direction range
+ [0, 1]; the other range depends upon the relative sizes.*/
+ double effective_height = height;
+ double effective_width = width;
+ double inset, axis_inset;
+ if((INSET_PERCENT > 0) && (INSET_PERCENT < 1.0)) {
+ inset = ((effective_height > effective_width)?effective_width:effective_height)*INSET_PERCENT;
+ effective_height -= inset;
+ effective_width -= inset;
+ }
+ if((gw->graph->xaxis != NULL) && (gw->graph->yaxis != NULL)) {
+ /*key off the smaller size.*/
+ axis_inset = ((effective_height > effective_width)?effective_width:effective_height)*TITLE_PERCENT;
+ effective_height -= axis_inset;
+ effective_width -= axis_inset;
+ }else if(gw->graph->xaxis != NULL) {
+ effective_height -= effective_height*TITLE_PERCENT;
+ }else if(gw->graph->yaxis != NULL) {
+ effective_width -= effective_width*TITLE_PERCENT;
+ }
+ if(effective_width > effective_height) {
+ cxt.xmax = effective_width/effective_height;
+ cxt.ymax = 1.0;
+ }else{
+ cxt.xmax = 1.0;
+ cxt.ymax = effective_height/effective_width;
+ }
+ /*Convert from data space to the semi-normalized space*/
+ double xscaling = (gw->graph->points->len == 1)? cxt.xmax : (cxt.xmax/(maxx-minx));
+ 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, "move_to(%d, %g->%g, %g->%g)\n", cr, graph_data[0], graph->allocation.x + graph_data[0]*(graph->allocation.width), graph_data[1], graph->allocation.y + graph_data[1]*(graph->allocation.height));
+ 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, x0, y0+height);
- cairo_scale(cr, width, -height);
- cairo_set_line_width(cr, 0.05);
- g_ptr_array_foreach(GRAPH_WIDGET(graph)->graph->points, &draw_point, (gpointer)&cxt);
+ 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, "Georgia",
+ CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
+ cairo_set_font_size (cr, 0.05);
+ if(gw->graph->lines != NULL) {
+ cairo_set_source_rgba(cr, 0, 0, 0, 0.25);
+ g_ptr_array_foreach(gw->graph->lines, &draw_lines, (gpointer)&cxt);
+ cairo_stroke(cr);
+ }
+ cairo_set_source_rgb(cr, 1, 1, 1);
+ cairo_fill_preserve(cr);
+ 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, 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, cxt.ymax);
+ cairo_restore(cr);
+ }
+ cairo_stroke(cr);
cairo_restore(cr);
}
Graph* graph_widget_get_graph(GraphWidget* gw) {
return gw->graph;
}
+
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