4 ** Made by (Johnny Q. Hacker)
5 ** Login <solarion@johnathan>
10 Copyright (C) 2008 Joseph Pingenot
12 This program is free software: you can redistribute it and/or modify
13 it under the terms of the GNU Affero General Public License as published by
14 the Free Software Foundation, either version 3 of the License, or
15 (at your option) any later version.
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU Affero General Public License for more details.
22 You should have received a copy of the GNU Affero General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>.
25 **Many thanks to Davyd Madeley for the excellent Cairo Widget Tutorial
26 ** at http://gnomejournal.org/article/34/writing-a-widget-using-cairo-and-gtk28
28 ** Started on Thu Jul 17 10:51:32 2008 Johnny Q. Hacker
29 ** Last update Thu Oct 8 17:13:50 2009 Johnny Q. Hacker
32 #include <graphwidget.h>
35 G_DEFINE_TYPE(GraphWidget, graph_widget, GTK_TYPE_DRAWING_AREA);
37 #define INSET_PERCENT 0.1
38 #define TITLE_PERCENT 0.15
39 #define DEBUG_DRAW_AXIS
41 struct drawing_context {
49 /*Semi-normalized maxima*/
52 cairo_matrix_t data_scale;
53 cairo_matrix_t data_xlat;
56 static void draw_point(gpointer data, gpointer user_data) {
57 struct drawing_context *cxt = user_data;
58 struct graph_point *pt = data;
59 double x = (pt->x + cxt->xoffset)*cxt->xscaling;
60 double y = (pt->y + cxt->yoffset)*cxt->yscaling;
61 cairo_move_to(cxt->cr, x, y);
62 cairo_arc(cxt->cr, x, y, cxt->radius, 0, 2*M_PI);
63 if(pt->label != NULL) {
65 cairo_scale(cxt->cr, 1, -1);
66 cairo_show_text(cxt->cr, pt->label->str);
67 cairo_restore(cxt->cr);
71 static void draw_lines(gpointer data, gpointer user_data) {
72 struct drawing_context *cxt = user_data;
73 struct graph_line *l = data;
74 double p0_x = (l->p0_x + cxt->xoffset)*cxt->xscaling;
75 double p0_y = (l->p0_y + cxt->yoffset)*cxt->yscaling;
76 double p1_x = (l->p1_x + cxt->xoffset)*cxt->xscaling;
77 double p1_y = (l->p1_y + cxt->yoffset)*cxt->yscaling;
78 double p2_x = (l->p2_x + cxt->xoffset)*cxt->xscaling;
79 double p2_y = (l->p2_y + cxt->yoffset)*cxt->yscaling;
80 double p3_x = (l->p3_x + cxt->xoffset)*cxt->xscaling;
81 double p3_y = (l->p3_y + cxt->yoffset)*cxt->yscaling;
83 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);
85 cairo_move_to(cxt->cr, p0_x, p0_y);
86 cairo_curve_to(cxt->cr, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
89 static void draw_axis(struct drawing_context* cxt, struct graph_axis *axis, double scaling, double offset, double max) {
90 #ifdef DEBUG_DRAW_AXIS
91 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);
93 cairo_move_to(cxt->cr, 0, 0);
94 cairo_line_to(cxt->cr, max, 0);
96 register double pos, mpos, smpos;
97 for(i=0; i<axis->major; i++) {
98 pos=i*axis->major_step + axis->major_start;
99 cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
100 cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
101 for(k=0; k<axis->subminor; k++) {
102 smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + pos;
103 cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
104 cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
106 for(j=0; j<axis->minor; j++) {
107 mpos=(j+1)*(axis->major_step/(axis->minor+1)) + pos;
108 cairo_move_to(cxt->cr, (mpos + offset)*scaling, 0);
109 cairo_line_to(cxt->cr, (mpos + offset)*scaling, 0.025);
110 for(k=0; k<axis->subminor; k++) {
111 smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + mpos;
112 cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
113 cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
117 pos=i*axis->major_step + axis->major_start;
118 cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
119 cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
122 static void draw(GtkWidget *graph, cairo_t *cr) {
123 struct drawing_context cxt;
124 GraphWidget *gw = GRAPH_WIDGET(graph);
126 fprintf(stderr, "draw(%d, %d)\n", (int)graph, (int)cr);
127 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);
129 double x0=graph->allocation.x;
130 double y0=graph->allocation.y;
131 double height=graph->allocation.height;
132 double width=graph->allocation.width;
133 double minx = gw->graph->minx;
134 double maxx = gw->graph->maxx;
135 double miny = gw->graph->miny;
136 double maxy = gw->graph->maxy;
137 if(gw->graph->xaxis != NULL) {
138 minx = gw->graph->xaxis->major_start;
139 maxx = gw->graph->xaxis->major_start + gw->graph->xaxis->major_step*gw->graph->xaxis->major;
141 if(gw->graph->yaxis != NULL) {
142 miny = gw->graph->yaxis->major_start;
143 maxy = gw->graph->yaxis->major_start + gw->graph->yaxis->major_step*gw->graph->yaxis->major;
148 /*Set up our semi-normalized scaling. The shortest direction range
149 [0, 1]; the other range depends upon the relative sizes.*/
150 double effective_height = height;
151 double effective_width = width;
152 double inset, axis_inset;
153 if((INSET_PERCENT > 0) && (INSET_PERCENT < 1.0)) {
154 inset = ((effective_height > effective_width)?effective_width:effective_height)*INSET_PERCENT;
155 effective_height -= inset;
156 effective_width -= inset;
158 if((gw->graph->xaxis != NULL) && (gw->graph->yaxis != NULL)) {
159 /*key off the smaller size.*/
160 axis_inset = ((effective_height > effective_width)?effective_width:effective_height)*TITLE_PERCENT;
161 effective_height -= axis_inset;
162 effective_width -= axis_inset;
163 }else if(gw->graph->xaxis != NULL) {
164 effective_height -= effective_height*TITLE_PERCENT;
165 }else if(gw->graph->yaxis != NULL) {
166 effective_width -= effective_width*TITLE_PERCENT;
168 if(effective_width > effective_height) {
169 cxt.xmax = effective_width/effective_height;
173 cxt.ymax = effective_height/effective_width;
175 /*Convert from data space to the semi-normalized space*/
176 double xscaling = (gw->graph->points->len == 1)? cxt.xmax : (cxt.xmax/(maxx-minx));
177 double yscaling = (gw->graph->points->len == 1)? cxt.ymax : (cxt.ymax/(maxy-miny));
178 double xoffset = (gw->graph->points->len == 1)? (-minx/2) : (-minx);
179 double yoffset = (gw->graph->points->len == 1)? (-miny/2) : (-miny);
180 /*Finish up our context information.*/
181 cxt.xscaling = (gw->graph->points->len == 1)? cxt.xmax : (cxt.xmax/(((maxx - minx)==0)?1:(maxx-minx)));
182 cxt.yscaling = (gw->graph->points->len == 1)? cxt.ymax : (cxt.ymax/(((maxy - miny)==0)?1:(maxy-miny)));
183 cxt.xoffset = (gw->graph->points->len == 1)? (-minx/2) : (-minx);
184 cxt.yoffset = (gw->graph->points->len == 1)? (-miny/2) : (-miny);
185 cairo_matrix_translate(&(cxt.data_xlat), xoffset, yoffset);
186 cairo_matrix_scale(&(cxt.data_scale), xscaling, yscaling);
188 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);
189 fprintf(stderr, "x0=%g, y0=%g, width=%g, height=%g\n", x0, y0, height, width);
190 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));
192 double offset_height = ((width>=height)?height*INSET_PERCENT:0);;
193 double offset_width = ((height>=width)?width*INSET_PERCENT:0);
194 double inset_height = height - offset_height;
195 double inset_width = width - offset_width;
197 cairo_translate(cr, x0 + (width - effective_width) - inset/2, y0 + effective_height + inset/2);
198 cairo_scale(cr, effective_width/cxt.xmax, -effective_height/cxt.ymax);
199 cairo_set_line_width(cr, 0.005);
200 cairo_select_font_face (cr, "Georgia",
201 CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
202 cairo_set_font_size (cr, 0.05);
203 if(gw->graph->lines != NULL) {
204 cairo_set_source_rgba(cr, 0, 0, 0, 0.25);
205 g_ptr_array_foreach(gw->graph->lines, &draw_lines, (gpointer)&cxt);
208 cairo_set_source_rgb(cr, 1, 1, 1);
209 cairo_fill_preserve(cr);
210 cairo_set_source_rgb(cr, 0, 0, 0);
211 g_ptr_array_foreach(gw->graph->points, &draw_point, (gpointer)&cxt);
212 if(gw->graph->xaxis != NULL)
213 draw_axis(&cxt, gw->graph->xaxis, cxt.xscaling, cxt.xoffset, cxt.xmax);
214 if(gw->graph->yaxis != NULL) {
216 cairo_matrix_t matrix = { .xx=0, .xy = 1, .x0 = 0, .yx = 1, .yy = 0, .y0 = 0 };
217 cairo_transform(cr, &matrix);
218 draw_axis(&cxt, gw->graph->yaxis, cxt.yscaling, cxt.yoffset, cxt.ymax);
225 static gboolean graph_widget_expose(GtkWidget *graph, GdkEventExpose *event) {
226 cairo_t *cr = gdk_cairo_create(graph->window);
227 cairo_rectangle(cr, event->area.x, event->area.y, event->area.width, event->area.height);
234 static void graph_widget_class_init(GraphWidgetClass *klass) {
235 GtkWidgetClass *widget_class;
236 widget_class = GTK_WIDGET_CLASS(klass);
237 widget_class->expose_event = graph_widget_expose;
240 static void graph_widget_init(GraphWidget *graph) {
242 graph->graph = graph_new();
245 GtkWidget *graph_widget_new(void) {
246 return g_object_new(GRAPH_WIDGET_TYPE, NULL);
249 Graph* graph_widget_get_graph(GraphWidget* gw) {