X-Git-Url: http://git.maemo.org/git/?p=scdataviz;a=blobdiff_plain;f=graph.c;h=1af3cb8d5276e0c71be6cf7f1027cfddc2e2d0df;hp=6da0fb693edc30d9f44954f4f6b7abc579c2d5d0;hb=f3ddf2cd811f53afd0edaa3b1263035d9faab318;hpb=a954a12134959eab351047489430c57f6281f6c7;ds=sidebyside diff --git a/graph.c b/graph.c index 6da0fb6..1af3cb8 100644 --- a/graph.c +++ b/graph.c @@ -6,20 +6,20 @@ ** - Copyright (C) 2008 Joseph Pingenot +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 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. +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 . +You should have received a copy of the GNU Affero General Public License +along with this program. If not, see . **Many thanks to Davyd Madeley for the excellent Cairo Tutorial @@ -31,6 +31,7 @@ #include #include +#include G_DEFINE_TYPE(Graph, graph, G_TYPE_OBJECT); @@ -42,26 +43,119 @@ static void graph_class_init(GraphClass *klass) { static void graph_init(Graph *graph) { graph->symbol = CIRCLE; graph->points = g_ptr_array_new(); + graph->lines = NULL; } Graph *graph_new(void) { return g_object_new(GRAPH_TYPE, NULL); } -int graph_add_point(Graph* graph, double x, double y) { - double *point = (double*)malloc(2*sizeof(double)); - if(point == NULL) return 1; - point[0] = x; - point[1] = y; - g_ptr_array_add(graph->points, (gpointer)point); - if(graph->points->len == 1) { - graph->maxx = graph->minx = x; - graph->maxy = graph->miny = y; +/*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(x > graph->maxx) graph->maxx = x; - if(x < graph->minx) graph->minx = x; - if(y > graph->maxy) graph->maxy = y; - if(y < graph->miny) graph->miny = y; + 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(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; +}