4 ** Made by (Johnny Q. Hacker)
5 ** Login <solarion@johnathan>
9 Copyright (C) 2008 Joseph Pingenot
11 This program is free software: you can redistribute it and/or modify
12 it under the terms of the GNU Affero General Public License as published by
13 the Free Software Foundation, either version 3 of the License, or
14 (at your option) any later version.
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU Affero General Public License for more details.
21 You should have received a copy of the GNU Affero General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>.
25 **Many thanks to Davyd Madeley for the excellent Cairo Tutorial
26 ** at http://gnomejournal.org/article/34/writing-a--using-cairo-and-gtk28
28 ** Started on Thu Jul 17 10:51:32 2008 Johnny Q. Hacker
29 ** Last update Sun May 12 01:17:25 2002 Speed Blue
37 G_DEFINE_TYPE(Graph, graph, G_TYPE_OBJECT);
39 static void graph_class_init(GraphClass *klass) {
40 GObjectClass *gobject_klass;
41 gobject_klass = G_OBJECT_CLASS(klass);
44 static void graph_init(Graph *graph) {
45 graph->symbol = CIRCLE;
46 graph->points = g_ptr_array_new();
48 graph->xaxis = graph->yaxis = NULL;
51 Graph *graph_new(void) {
52 return g_object_new(GRAPH_TYPE, NULL);
55 /*1 means you're stupid and passed NULL*/
56 int graph_add_graph_point(Graph* graph, struct graph_point *pt) {
57 if(pt == NULL) return 1;
58 g_ptr_array_add(graph->points, pt);
59 if((graph->points->len == 1) && ((graph->lines == NULL) || (graph->lines->len == 0))) {
60 graph->maxx = graph->minx = pt->x;
61 graph->maxy = graph->miny = pt->y;
63 if(pt->x > graph->maxx) graph->maxx = pt->x;
64 if(pt->x < graph->minx) graph->minx = pt->x;
65 if(pt->y > graph->maxy) graph->maxy = pt->y;
66 if(pt->y < graph->miny) graph->miny = pt->y;
73 *1 means failed to allocate point
74 *NOTE: label is duplicated if not NULL (using g_strdup)
76 int graph_add_point(Graph* graph, double x, double y, const GString *label) {
77 struct graph_point *pt = (struct graph_point*)malloc(sizeof(struct graph_point));
78 if(pt == NULL) return 1;
81 pt->label = (label)?g_string_new(label->str):NULL;
82 graph_add_graph_point(graph, pt);
86 int graph_add_graph_line(Graph* graph, struct graph_line *l) {
87 if(l == NULL) return 1;
88 if(graph->lines == NULL) {
89 if((graph->lines = g_ptr_array_new()) == NULL) return 1;
91 g_ptr_array_add(graph->lines, l);
92 if((graph->points->len == 0) &&
93 (graph->lines->len == 1)) {
94 graph->maxx = graph->minx = l->p0_x;
95 graph->maxy = graph->miny = l->p0_y;
97 if(l->p0_x > graph->maxx) graph->maxx = l->p0_x;
98 if(l->p0_x < graph->minx) graph->minx = l->p0_x;
99 if(l->p0_y > graph->maxy) graph->maxy = l->p0_y;
100 if(l->p0_y < graph->miny) graph->miny = l->p0_y;
102 if(l->p3_x > graph->maxx) graph->maxx = l->p3_x;
103 if(l->p3_x < graph->minx) graph->minx = l->p3_x;
104 if(l->p3_y > graph->maxy) graph->maxy = l->p3_y;
105 if(l->p3_y < graph->miny) graph->miny = l->p3_y;
110 int graph_add_line(Graph* graph, double p0_x, double p0_y, double p1_x, double p1_y, double p2_x, double p2_y, double p3_x, double p3_y) {
112 fprintf(stderr, "graph_add_line(%d, 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", (unsigned int) graph, p0_x, p0_y, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
114 struct graph_line *l;
115 if((l=(struct graph_line*)malloc(sizeof(struct graph_line))) == NULL) return 2;
124 return graph_add_graph_line(graph, l);
129 struct graph_point *p0;
132 static void linear_interpolate(gpointer data, gpointer user_data) {
133 struct cxt *cxt = user_data;
134 struct graph_point *p3 = data;
135 if(cxt->p0 != NULL) {
136 double p1_x = (p3->x + 2*cxt->p0->x)/3.0;
137 double p1_y = (p3->y + 2*cxt->p0->y)/3.0;
138 double p2_x = (2*p3->x + cxt->p0->x)/3.0;
139 double p2_y = (2*p3->y + cxt->p0->y)/3.0;
140 graph_add_line(cxt->graph, cxt->p0->x, cxt->p0->y, p1_x, p1_y, p2_x, p2_y, p3->x, p3->y);
145 void graph_add_linear_connectors(Graph* graph) {
149 g_ptr_array_foreach(graph->points, &linear_interpolate, &cxt);
152 void graph_bezier_linear_to_cubic(double x0, double x3, double *x1, double *x2) {
153 *x1 = (x3 + 2.0*x0)/3.0;
154 *x2 = (2.0*x3 + x0)/3.0;
157 void graph_bezier_linear_to_quadratic(double x0, double x3, double *x1) {
161 void graph_bezier_quadratic_to_cubic(double x0, double x3, double *x1, double *x2) {
162 *x2 = (x3-2.0*(*x1))/3.0;
163 *x1 = (x0-2.0*(*x1))/3.0;
166 void graph_set_xaxis(Graph *g, struct graph_axis *axis) {
167 if(g->xaxis != NULL) {
172 void graph_set_yaxis(Graph *g, struct graph_axis *axis) {
173 if(g->yaxis != NULL) {
179 int graph_autoset_xaxis(Graph *g, GString *title) {
180 struct graph_axis *axis;
184 if(g->points->len == 0) {
187 if((axis=(struct graph_axis *)malloc(sizeof(struct graph_axis))) == NULL) {
190 if(g->points->len == 1) {
194 axis->major_start=g->minx;
195 axis->major_step=g->maxx;
197 range_mag = round(pow(10, floor(log10(g->maxx-g->minx))));
198 start_mag = copysign(round(pow(10, floor(log10(fabs(g->minx))))), g->minx);
199 stop_mag = copysign(round(pow(10, floor(log10(fabs(g->maxx))))), g->maxx);
203 axis->major_start=start_mag;
204 axis->major_step=range_mag/(axis->major);
206 axis->title=g_string_new(title->str);
207 graph_set_xaxis(g, axis);
211 int graph_autoset_yaxis(Graph *g, GString *title) {