--- /dev/null
+/*
+** Graph.c
+**
+** Made by (Johnny Q. Hacker)
+** Login <solarion@johnathan>
+**
+
+
+Copyright (C) 2008 Joseph Pingenot
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+**Many thanks to Davyd Madeley for the excellent Cairo Tutorial
+** at http://gnomejournal.org/article/34/writing-a--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
+*/
+
+#include <graph.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+
+#ifdef DEBUG
+#define DEBUG_AUTOAXIS
+#endif
+
+G_DEFINE_TYPE(Graph, graph, G_TYPE_OBJECT);
+
+static void graph_class_init(GraphClass *klass) {
+ GObjectClass *gobject_klass;
+ gobject_klass = G_OBJECT_CLASS(klass);
+}
+
+static void graph_init(Graph *graph) {
+ graph->symbol = CIRCLE;
+ graph->points = g_ptr_array_new();
+ graph->lines = NULL;
+ graph->xaxis = graph->yaxis = NULL;
+}
+
+Graph *graph_new(void) {
+ return g_object_new(GRAPH_TYPE, NULL);
+}
+
+/*1 means you're stupid and passed NULL*/
+int graph_add_graph_point(Graph* graph, struct graph_point *pt) {
+ if(pt == NULL) return 1;
+ g_ptr_array_add(graph->points, pt);
+ if((graph->points->len == 1) && ((graph->lines == NULL) || (graph->lines->len == 0))) {
+ graph->maxx = graph->minx = pt->x;
+ graph->maxy = graph->miny = pt->y;
+ }else{
+ if(pt->x > graph->maxx) graph->maxx = pt->x;
+ if(pt->x < graph->minx) graph->minx = pt->x;
+ if(pt->y > graph->maxy) graph->maxy = pt->y;
+ if(pt->y < graph->miny) graph->miny = pt->y;
+ }
+ return 0;
+}
+
+/*
+ *
+ *1 means failed to allocate point
+ *NOTE: label is duplicated if not NULL (using g_strdup)
+ */
+int graph_add_point(Graph* graph, double x, double y, const GString *label) {
+ struct graph_point *pt = (struct graph_point*)malloc(sizeof(struct graph_point));
+ if(pt == NULL) return 1;
+ pt->x = x;
+ pt->y = y;
+ pt->label = (label)?g_string_new(label->str):NULL;
+ graph_add_graph_point(graph, pt);
+ return 0;
+}
+
+int graph_add_graph_line(Graph* graph, struct graph_line *l) {
+ if(l == NULL) return 1;
+ if(graph->lines == NULL) {
+ if((graph->lines = g_ptr_array_new()) == NULL) return 1;
+ }
+ g_ptr_array_add(graph->lines, l);
+ if((graph->points->len == 0) &&
+ (graph->lines->len == 1)) {
+ graph->maxx = graph->minx = l->p0_x;
+ graph->maxy = graph->miny = l->p0_y;
+ }else{
+ if(l->p0_x > graph->maxx) graph->maxx = l->p0_x;
+ if(l->p0_x < graph->minx) graph->minx = l->p0_x;
+ if(l->p0_y > graph->maxy) graph->maxy = l->p0_y;
+ if(l->p0_y < graph->miny) graph->miny = l->p0_y;
+ }
+ if(l->p3_x > graph->maxx) graph->maxx = l->p3_x;
+ if(l->p3_x < graph->minx) graph->minx = l->p3_x;
+ if(l->p3_y > graph->maxy) graph->maxy = l->p3_y;
+ if(l->p3_y < graph->miny) graph->miny = l->p3_y;
+ return 0;
+}
+
+
+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) {
+ #ifdef DEBUG
+ 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);
+ #endif
+ struct graph_line *l;
+ if((l=(struct graph_line*)malloc(sizeof(struct graph_line))) == NULL) return 2;
+ l->p0_x=p0_x;
+ l->p0_y=p0_y;
+ l->p1_x=p1_x;
+ l->p1_y=p1_y;
+ l->p2_x=p2_x;
+ l->p2_y=p2_y;
+ l->p3_x=p3_x;
+ l->p3_y=p3_y;
+ return graph_add_graph_line(graph, l);
+}
+
+struct cxt {
+ Graph *graph;
+ struct graph_point *p0;
+};
+
+static void linear_interpolate(gpointer data, gpointer user_data) {
+ struct cxt *cxt = user_data;
+ struct graph_point *p3 = data;
+ if(cxt->p0 != NULL) {
+ double p1_x = (p3->x + 2*cxt->p0->x)/3.0;
+ double p1_y = (p3->y + 2*cxt->p0->y)/3.0;
+ double p2_x = (2*p3->x + cxt->p0->x)/3.0;
+ double p2_y = (2*p3->y + cxt->p0->y)/3.0;
+ graph_add_line(cxt->graph, cxt->p0->x, cxt->p0->y, p1_x, p1_y, p2_x, p2_y, p3->x, p3->y);
+ }
+ cxt->p0 = p3;
+}
+
+void graph_add_linear_connectors(Graph* graph) {
+ struct cxt cxt;
+ cxt.graph = graph;
+ cxt.p0 = NULL;
+ g_ptr_array_foreach(graph->points, &linear_interpolate, &cxt);
+}
+
+void graph_bezier_linear_to_cubic(double x0, double x3, double *x1, double *x2) {
+ *x1 = (x3 + 2.0*x0)/3.0;
+ *x2 = (2.0*x3 + x0)/3.0;
+}
+
+void graph_bezier_linear_to_quadratic(double x0, double x3, double *x1) {
+ *x1 = (x3 + x0)/2.0;
+}
+
+void graph_bezier_quadratic_to_cubic(double x0, double x3, double *x1, double *x2) {
+ *x2 = (x3-2.0*(*x1))/3.0;
+ *x1 = (x0-2.0*(*x1))/3.0;
+}
+
+void graph_set_xaxis(Graph *g, struct graph_axis *axis) {
+ if(g->xaxis != NULL) {
+ free(g->xaxis);
+ }
+ g->xaxis=axis;
+}
+void graph_set_yaxis(Graph *g, struct graph_axis *axis) {
+ if(g->yaxis != NULL) {
+ free(g->yaxis);
+ }
+ g->yaxis=axis;
+}
+
+struct graph_axis* autoset_axis(Graph* g, GString* title, double min, double max) {
+ struct graph_axis *axis;
+ double range_mag;
+ double start_mag;
+ double stop_mag;
+ int i, j;
+ if(g->points->len == 0) {
+ return NULL;
+ }
+ if((axis=(struct graph_axis *)malloc(sizeof(struct graph_axis))) == NULL) {
+ return NULL;
+ }
+ if(g->points->len == 1) {
+ axis->major=1;
+ axis->minor=0;
+ axis->subminor=0;
+ axis->major_start=min;
+ axis->major_step=max;
+ }else{
+ range_mag = logb(max - min);
+ if(min == 0)
+ start_mag = 0;
+ else
+ start_mag = copysign(pow(10, floor(log10(min))), min);
+ if(max == 0)
+ stop_mag = 0;
+ else
+ stop_mag = copysign(pow(10, ceil(log10(max))), max);
+ for(i=1; i<9; i++) {
+ if(i*start_mag > min) break;
+ }
+ i--;
+ for(j=10; j>1; j--) {
+ if(j*(stop_mag/10) < max) break;
+ }
+ j++;
+ axis->major=10;
+ axis->minor=1;
+ axis->subminor=4;
+ axis->major_start=i*start_mag;
+ axis->major_step=(j*(stop_mag/10) - axis->major_start)/(axis->major);
+ }
+ axis->title=g_string_new(title->str);
+ #ifdef DEBUG_AUTOAXIS
+ 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)))));
+ 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)))));
+ 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);
+ #endif
+ return axis;
+}
+
+int graph_autoset_xaxis(Graph *g, GString *title) {
+ graph_set_xaxis(g, autoset_axis(g, title, g->minx, g->maxx));
+ return 0;
+}
+
+int graph_autoset_yaxis(Graph *g, GString *title) {
+ graph_set_yaxis(g, autoset_axis(g, title, g->miny, g->maxy));
+ return 0;
+}
projects / scdataviz / blobdiff