static void
gtk_plot_surface_draw_triangle (GtkPlotSurface *surface,
GtkPlotDTtriangle *triangle,
gint sign)
{
GtkPlot *plot;
GtkPlotVector side1, side2, light, normal;
GtkPlotVector points[3];
GtkPlotPoint t[3];
GdkDrawable *drawable;
GdkColor color, real_color;
gdouble factor, norm;
gboolean visible = TRUE;
plot = GTK_PLOT(GTK_PLOT_DATA(surface)->plot);
drawable = plot->drawable;
points[0].x = triangle->na->x;
points[0].y = triangle->na->y;
points[0].z = triangle->na->z;
points[1].x = triangle->nb->x;
points[1].y = triangle->nb->y;
points[1].z = triangle->nb->z;
points[2].x = triangle->nc->x;
points[2].y = triangle->nc->y;
points[2].z = triangle->nc->z;
t[0].x = triangle->na->px;
t[0].y = triangle->na->py;
t[1].x = triangle->nb->px;
t[1].y = triangle->nb->py;
t[2].x = triangle->nc->px;
t[2].y = triangle->nc->py;
side1.x = (points[1].x - points[0].x) * sign;
side1.y = (points[1].y - points[0].y) * sign;
side1.z = (points[1].z - points[0].z) * sign;
side2.x = (points[2].x - points[0].x) * sign;
side2.y = (points[2].y - points[0].y) * sign;
side2.z = (points[2].z - points[0].z) * sign;
if(surface->height_gradient){
gtk_plot_data_get_gradient_level(GTK_PLOT_DATA(surface),
(triangle->na->z +
triangle->nb->z +
triangle->nc->z) / 3.0,
&real_color);
}else{
color = surface->color;
light = surface->light;
norm = sqrt(light.x*light.x + light.y*light.y + light.z*light.z);
light.x /= norm;
light.y /= norm;
light.z /= norm;
if(GTK_IS_PLOT3D(plot)){
normal.x = side1.y * side2.z - side1.z * side2.y;
normal.y = side1.z * side2.x - side1.x * side2.z;
normal.z = side1.x * side2.y - side1.y * side2.x;
norm = sqrt(normal.x*normal.x + normal.y*normal.y + normal.z*normal.z);
factor = (normal.x*light.x + normal.y*light.y + normal.z*light.z) / norm;
} else {
factor = 1.0;
}
gtk_plot_surface_lighting(&color, &real_color,
factor, surface->ambient);
}
if(GTK_IS_PLOT3D(plot))
if(((t[1].x-t[0].x)*(t[2].y-t[0].y) - (t[1].y-t[0].y)*(t[2].x-t[0].x))*sign > 0)
visible = FALSE;
if(visible)
gtk_plot_pc_set_color(plot->pc, &real_color);
else
gtk_plot_pc_set_color(plot->pc, &surface->shadow);
gtk_plot_pc_draw_polygon(plot->pc, !surface->transparent, t, 3);
if(visible)
gtk_plot_pc_set_color(plot->pc, &surface->grid_foreground);
else
gtk_plot_pc_set_color(plot->pc, &surface->grid_background);
if(surface->show_mesh || !surface->dt->quadrilateral)
gtk_plot_pc_draw_polygon(plot->pc, FALSE, t, 3);
if(!surface->show_mesh && surface->show_grid && surface->dt->quadrilateral)
gtk_plot_pc_draw_line(plot->pc,
t[1].x, t[1].y, t[2].x, t[2].y);
}
static void
gtk_plot_flux_draw_arrow(GtkPlotFlux *flux, gdouble x1, gdouble y1, gdouble x2, gdouble y2)
{
GtkPlot *plot;
GtkPlotData *data;
GtkPlotPoint arrow[3];
gdouble xm, ym;
gdouble width, height;
gdouble arrow_width;
gdouble line_width;
gdouble angle;
gdouble length;
gdouble m;
data = GTK_PLOT_DATA(flux);
plot = data->plot;
m = plot->magnification;
width = fabs(x2 - x1);
height = fabs(y2 - y1);
/* This is a nan */
if (width != width || height != height) return;
if(width == 0 && height == 0) return;
if(width != 0)
angle = atan2((y2 - y1), (x2 - x1));
else
angle = asin((y2 - y1)/height);
length = (y2 - y1)*(y2 - y1) + (x2 - x1)*(x2 - x1);
if (length > 0.0) length = sqrt(length);
arrow_width = flux->arrow_width;
line_width = data->symbol.border.line_width;
gtk_plot_pc_set_color(plot->pc, &data->symbol.color);
gtk_plot_pc_set_lineattr (plot->pc, line_width, 0, 0, 0);
gtk_plot_pc_set_dash (plot->pc, 0, 0, 0);
if(flux->centered && width != 0){
x1 -= cos(angle) * length / 2.0;
x2 -= cos(angle) * length / 2.0;
}
if(flux->centered && height != 0){
y1 -= sin(angle) * length / 2.0;
y2 -= sin(angle) * length / 2.0;
}
if(flux->arrow_style == GTK_PLOT_SYMBOL_EMPTY)
gtk_plot_pc_draw_line(plot->pc, x1, y1, x2, y2);
else
gtk_plot_pc_draw_line(plot->pc, x1, y1,
x2 - flux->arrow_length * m * cos(angle) / 2.,
y2 - flux->arrow_length * m * sin(angle) / 2.);
arrow[1].x = x2;
arrow[1].y = y2;
xm = x2 - cos(angle) * flux->arrow_length * m;
ym = y2 - sin(angle) * flux->arrow_length * m;
arrow[0].x = xm - sin(angle)* arrow_width * m / 2.0;
arrow[0].y = ym + cos(angle)* arrow_width * m / 2.0;
arrow[2].x = xm + sin(angle)* arrow_width * m / 2.0;
arrow[2].y = ym - cos(angle)* arrow_width * m / 2.0;
switch(flux->arrow_style){
case GTK_PLOT_SYMBOL_EMPTY:
gtk_plot_pc_draw_lines (plot->pc, arrow, 3);
break;
case GTK_PLOT_SYMBOL_OPAQUE:
gtk_plot_pc_set_color(plot->pc, &plot->background);
gtk_plot_pc_draw_polygon (plot->pc, TRUE, arrow, 3);
gtk_plot_pc_set_color(plot->pc, &data->symbol.color);
gtk_plot_pc_draw_polygon (plot->pc, FALSE, arrow, 3);
break;
case GTK_PLOT_SYMBOL_FILLED:
gtk_plot_pc_draw_polygon (plot->pc, TRUE, arrow, 3);
}
}
