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 Thu Oct 15 21:51:41 2009 Johnny Q. Hacker
39 #define DEBUG_AUTOAXIS
42 G_DEFINE_TYPE(Graph, graph, G_TYPE_OBJECT);
44 static void graph_class_init(GraphClass *klass) {
45 GObjectClass *gobject_klass;
46 gobject_klass = G_OBJECT_CLASS(klass);
49 static void graph_init(Graph *graph) {
50 graph->symbol = CIRCLE;
51 graph->points = g_ptr_array_new();
53 graph->xaxis = graph->yaxis = NULL;
56 Graph *graph_new(void) {
57 return g_object_new(GRAPH_TYPE, NULL);
60 /*1 means you're stupid and passed NULL*/
61 int graph_add_graph_point(Graph* graph, struct graph_point *pt) {
62 if(pt == NULL) return 1;
63 g_ptr_array_add(graph->points, pt);
64 if((graph->points->len == 1) && ((graph->lines == NULL) || (graph->lines->len == 0))) {
65 graph->maxx = graph->minx = pt->x;
66 graph->maxy = graph->miny = pt->y;
68 if(pt->x > graph->maxx) graph->maxx = pt->x;
69 if(pt->x < graph->minx) graph->minx = pt->x;
70 if(pt->y > graph->maxy) graph->maxy = pt->y;
71 if(pt->y < graph->miny) graph->miny = pt->y;
78 *1 means failed to allocate point
79 *NOTE: label is duplicated if not NULL (using g_strdup)
81 int graph_add_point(Graph* graph, double x, double y, const GString *label) {
82 struct graph_point *pt = (struct graph_point*)malloc(sizeof(struct graph_point));
83 if(pt == NULL) return 1;
86 pt->label = (label)?g_string_new(label->str):NULL;
87 graph_add_graph_point(graph, pt);
91 int graph_add_graph_line(Graph* graph, struct graph_line *l) {
92 if(l == NULL) return 1;
93 if(graph->lines == NULL) {
94 if((graph->lines = g_ptr_array_new()) == NULL) return 1;
96 g_ptr_array_add(graph->lines, l);
97 if((graph->points->len == 0) &&
98 (graph->lines->len == 1)) {
99 graph->maxx = graph->minx = l->p0_x;
100 graph->maxy = graph->miny = l->p0_y;
102 if(l->p0_x > graph->maxx) graph->maxx = l->p0_x;
103 if(l->p0_x < graph->minx) graph->minx = l->p0_x;
104 if(l->p0_y > graph->maxy) graph->maxy = l->p0_y;
105 if(l->p0_y < graph->miny) graph->miny = l->p0_y;
107 if(l->p3_x > graph->maxx) graph->maxx = l->p3_x;
108 if(l->p3_x < graph->minx) graph->minx = l->p3_x;
109 if(l->p3_y > graph->maxy) graph->maxy = l->p3_y;
110 if(l->p3_y < graph->miny) graph->miny = l->p3_y;
115 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) {
117 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);
119 struct graph_line *l;
120 if((l=(struct graph_line*)malloc(sizeof(struct graph_line))) == NULL) return 2;
129 return graph_add_graph_line(graph, l);
134 struct graph_point *p0;
137 static void linear_interpolate(gpointer data, gpointer user_data) {
138 struct cxt *cxt = user_data;
139 struct graph_point *p3 = data;
140 if(cxt->p0 != NULL) {
141 double p1_x = (p3->x + 2*cxt->p0->x)/3.0;
142 double p1_y = (p3->y + 2*cxt->p0->y)/3.0;
143 double p2_x = (2*p3->x + cxt->p0->x)/3.0;
144 double p2_y = (2*p3->y + cxt->p0->y)/3.0;
145 graph_add_line(cxt->graph, cxt->p0->x, cxt->p0->y, p1_x, p1_y, p2_x, p2_y, p3->x, p3->y);
150 void graph_add_linear_connectors(Graph* graph) {
154 g_ptr_array_foreach(graph->points, &linear_interpolate, &cxt);
157 void graph_bezier_linear_to_cubic(double x0, double x3, double *x1, double *x2) {
158 *x1 = (x3 + 2.0*x0)/3.0;
159 *x2 = (2.0*x3 + x0)/3.0;
162 void graph_bezier_linear_to_quadratic(double x0, double x3, double *x1) {
166 void graph_bezier_quadratic_to_cubic(double x0, double x3, double *x1, double *x2) {
167 *x2 = (x3-2.0*(*x1))/3.0;
168 *x1 = (x0-2.0*(*x1))/3.0;
171 void graph_set_xaxis(Graph *g, struct graph_axis *axis) {
172 if(g->xaxis != NULL) {
177 void graph_set_yaxis(Graph *g, struct graph_axis *axis) {
178 if(g->yaxis != NULL) {
184 struct graph_axis* autoset_axis(Graph* g, GString* title, double min, double max) {
185 struct graph_axis *axis;
190 if(g->points->len == 0) {
193 if((axis=(struct graph_axis *)malloc(sizeof(struct graph_axis))) == NULL) {
196 if(g->points->len == 1) {
200 axis->major_start=min;
201 axis->major_step=max;
203 range_mag = logb(max - min);
207 start_mag = copysign(pow(10, floor(log10(min))), min);
211 stop_mag = copysign(pow(10, ceil(log10(max))), max);
213 if(i*start_mag > min) break;
216 for(j=10; j>1; j--) {
217 if(j*(stop_mag/10) < max) break;
223 axis->major_start=i*start_mag;
224 axis->major_step=(j*(stop_mag/10) - axis->major_start)/(axis->major);
226 axis->title=g_string_new(title->str);
227 #ifdef DEBUG_AUTOAXIS
228 fprintf(stderr, "graph_autoset_xaxis: xmin=%g, log10(xmin)=%g, floor=%g, pow=%g round=%g\n", min, log10(min), floor(log10(min)), pow(10, floor(log10(min))), round(pow(10, floor(log10(min)))));
229 fprintf(stderr, "graph_autoset_xaxis: xmax=%g, log10(xmax)=%g, floor=%g, pow=%g round=%g\n", max, log10(max), floor(log10(max)), pow(10, floor(log10(max))), round(pow(10, floor(log10(max)))));
230 fprintf(stderr, "graph_autoset_xaxis: xmin=%g,max=%g start_mag=%g, stop_mag=%g range_mag=%g\n", min, max, start_mag, stop_mag, range_mag);
235 int graph_autoset_xaxis(Graph *g, GString *title) {
236 graph_set_xaxis(g, autoset_axis(g, title, g->minx, g->maxx));
240 int graph_autoset_yaxis(Graph *g, GString *title) {
241 graph_set_yaxis(g, autoset_axis(g, title, g->miny, g->maxy));