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 Sun May 12 01:17:25 2002 Speed Blue
32 #include <graphwidget.h>
35 G_DEFINE_TYPE(GraphWidget, graph_widget, GTK_TYPE_DRAWING_AREA);
37 #define INSET_PERCENT 0.1
38 #define DEBUG_DRAW_AXIS
40 struct drawing_context {
50 static void draw_point(gpointer data, gpointer user_data) {
51 struct drawing_context *cxt = user_data;
52 struct graph_point *pt = data;
53 double x = (pt->x + cxt->xoffset)*cxt->xscaling;
54 double y = (pt->y + cxt->yoffset)*cxt->yscaling;
55 cairo_move_to(cxt->cr, x, y);
56 cairo_arc(cxt->cr, x, y, cxt->radius, 0, 2*M_PI);
57 if(pt->label != NULL) {
59 cairo_scale(cxt->cr, 1, -1);
60 cairo_show_text(cxt->cr, pt->label->str);
61 cairo_restore(cxt->cr);
65 static void draw_lines(gpointer data, gpointer user_data) {
66 struct drawing_context *cxt = user_data;
67 struct graph_line *l = data;
68 double p0_x = (l->p0_x + cxt->xoffset)*cxt->xscaling;
69 double p0_y = (l->p0_y + cxt->yoffset)*cxt->yscaling;
70 double p1_x = (l->p1_x + cxt->xoffset)*cxt->xscaling;
71 double p1_y = (l->p1_y + cxt->yoffset)*cxt->yscaling;
72 double p2_x = (l->p2_x + cxt->xoffset)*cxt->xscaling;
73 double p2_y = (l->p2_y + cxt->yoffset)*cxt->yscaling;
74 double p3_x = (l->p3_x + cxt->xoffset)*cxt->xscaling;
75 double p3_y = (l->p3_y + cxt->yoffset)*cxt->yscaling;
77 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);
79 cairo_move_to(cxt->cr, p0_x, p0_y);
80 cairo_curve_to(cxt->cr, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y);
83 static void draw_axis(struct drawing_context* cxt, struct graph_axis *axis, double scaling, double offset) {
84 #ifdef DEBUG_DRAW_AXIS
85 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);
87 cairo_move_to(cxt->cr, 0, 0);
88 cairo_line_to(cxt->cr, 1, 0);
90 register double pos, mpos, smpos;
91 for(i=0; i<axis->major; i++) {
92 pos=i*axis->major_step + axis->major_start;
93 cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
94 cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
95 for(k=0; k<axis->subminor; k++) {
96 smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + pos;
97 cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
98 cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
100 for(j=0; j<axis->minor; j++) {
101 mpos=(j+1)*(axis->major_step/(axis->minor+1)) + pos;
102 cairo_move_to(cxt->cr, (mpos + offset)*scaling, 0);
103 cairo_line_to(cxt->cr, (mpos + offset)*scaling, 0.025);
104 for(k=0; k<axis->subminor; k++) {
105 smpos=(k+1)*(axis->major_step/(axis->minor+1)/(axis->subminor+1)) + mpos;
106 cairo_move_to(cxt->cr, (smpos + offset)*scaling, 0);
107 cairo_line_to(cxt->cr, (smpos + offset)*scaling, 0.0125);
111 pos=i*axis->major_step + axis->major_start;
112 cairo_move_to(cxt->cr, (pos + offset)*scaling, 0);
113 cairo_line_to(cxt->cr, (pos + offset)*scaling, 0.05);
116 static void draw(GtkWidget *graph, cairo_t *cr) {
117 struct drawing_context cxt;
118 GraphWidget *gw = GRAPH_WIDGET(graph);
120 fprintf(stderr, "draw(%d, %d)\n", (int)graph, (int)cr);
121 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);
123 double x0=graph->allocation.x;
124 double y0=graph->allocation.y;
125 double height=graph->allocation.height;
126 double width=graph->allocation.width;
127 double minx = gw->graph->minx;
128 double maxx = gw->graph->maxx;
129 double miny = gw->graph->miny;
130 double maxy = gw->graph->maxy;
131 if(gw->graph->xaxis != NULL) {
132 minx = gw->graph->xaxis->major_start;
133 maxx = gw->graph->xaxis->major_start + gw->graph->xaxis->major_step*gw->graph->xaxis->major;
135 if(gw->graph->yaxis != NULL) {
136 miny = gw->graph->yaxis->major_start;
137 maxy = gw->graph->yaxis->major_start + gw->graph->yaxis->major_step*gw->graph->yaxis->major;
142 cxt.xscaling = (gw->graph->points->len == 1)? 1 : (1/(maxx - minx));
143 cxt.yscaling = (gw->graph->points->len == 1)? 1 : (1/(maxy - miny));
144 cxt.xoffset = (gw->graph->points->len == 1)? (-minx/2) : (-minx);
145 cxt.yoffset = (gw->graph->points->len == 1)? (-miny/2) : (-miny);
147 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);
148 fprintf(stderr, "x0=%g, y0=%g, width=%g, height=%g\n", x0, y0, height, width);
149 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));
151 double offset_height = ((width>=height)?height*INSET_PERCENT:0);;
152 double offset_width = ((height>=width)?width*INSET_PERCENT:0);
153 double inset_height = height - offset_height;
154 double inset_width = width - offset_width;
156 cairo_translate(cr, x0 + ((inset_width>inset_height)?(inset_width-inset_height)/2.0:0) + offset_width/2, y0+((inset_width > inset_height)?inset_height:inset_width) + ((inset_width>=inset_height)?0:(inset_height-inset_width)/2.0) + offset_height/2 );
157 cairo_scale(cr, (inset_width > inset_height)?inset_height:inset_width, (inset_width > inset_height)?-inset_height:-inset_width);
158 cairo_set_line_width(cr, 0.005);
159 cairo_select_font_face (cr, "Georgia",
160 CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
161 cairo_set_font_size (cr, 0.05);
162 if(gw->graph->lines != NULL) {
163 cairo_set_source_rgba(cr, 0, 0, 0, 0.25);
164 g_ptr_array_foreach(gw->graph->lines, &draw_lines, (gpointer)&cxt);
167 cairo_set_source_rgb(cr, 1, 1, 1);
168 cairo_fill_preserve(cr);
169 cairo_set_source_rgb(cr, 0, 0, 0);
170 g_ptr_array_foreach(gw->graph->points, &draw_point, (gpointer)&cxt);
171 if(gw->graph->xaxis != NULL)
172 draw_axis(&cxt, gw->graph->xaxis, cxt.xscaling, cxt.xoffset);
173 if(gw->graph->yaxis != NULL) {
175 cairo_matrix_t matrix = { .xx=0, .xy = 1, .x0 = 0, .yx = 1, .yy = 0, .y0 = 0 };
176 cairo_transform(cr, &matrix);
177 draw_axis(&cxt, gw->graph->yaxis, cxt.yscaling, cxt.yoffset);
184 static gboolean graph_widget_expose(GtkWidget *graph, GdkEventExpose *event) {
185 cairo_t *cr = gdk_cairo_create(graph->window);
186 cairo_rectangle(cr, event->area.x, event->area.y, event->area.width, event->area.height);
193 static void graph_widget_class_init(GraphWidgetClass *klass) {
194 GtkWidgetClass *widget_class;
195 widget_class = GTK_WIDGET_CLASS(klass);
196 widget_class->expose_event = graph_widget_expose;
199 static void graph_widget_init(GraphWidget *graph) {
201 graph->graph = graph_new();
204 GtkWidget *graph_widget_new(void) {
205 return g_object_new(GRAPH_WIDGET_TYPE, NULL);
208 Graph* graph_widget_get_graph(GraphWidget* gw) {