/* nuklear - v1.00 - public domain */
/* This is a simple node editor just to show a simple implementation and that
* it is possible to achieve it with this library. While all nodes inside this
* example use a simple color modifier as content you could change them
* to have your custom content depending on the node time.
* Biggest difference to most usual implementation is that this example does
* not have connectors on the right position of the property that it links.
* This is mainly done out of laziness and could be implemented as well but
* requires calculating the position of all rows and add connectors.
* In addition adding and removing nodes is quite limited at the
* moment since it is based on a simple fixed array. If this is to be converted
* into something more serious it is probably best to extend it.*/
struct node {
int ID;
char name[32];
struct nk_rect bounds;
float value;
struct nk_color color;
int input_count;
int output_count;
struct node *next;
struct node *prev;
};
struct node_link {
int input_id;
int input_slot;
int output_id;
int output_slot;
struct nk_vec2 in;
struct nk_vec2 out;
};
struct node_linking {
int active;
struct node *node;
int input_id;
int input_slot;
};
struct node_editor {
int initialized;
struct node node_buf[32];
struct node_link links[64];
struct node *begin;
struct node *end;
int node_count;
int link_count;
struct nk_rect bounds;
struct node *selected;
int show_grid;
struct nk_vec2 scrolling;
struct node_linking linking;
};
static struct node_editor nodeEditor;
static void
node_editor_push(struct node_editor *editor, struct node *node)
{
if (!editor->begin) {
node->next = NULL;
node->prev = NULL;
editor->begin = node;
editor->end = node;
} else {
node->prev = editor->end;
if (editor->end)
editor->end->next = node;
node->next = NULL;
editor->end = node;
}
}
static void
node_editor_pop(struct node_editor *editor, struct node *node)
{
if (node->next)
node->next->prev = node->prev;
if (node->prev)
node->prev->next = node->next;
if (editor->end == node)
editor->end = node->prev;
if (editor->begin == node)
editor->begin = node->next;
node->next = NULL;
node->prev = NULL;
}
static struct node*
node_editor_find(struct node_editor *editor, int ID)
{
struct node *iter = editor->begin;
while (iter) {
if (iter->ID == ID)
return iter;
iter = iter->next;
}
return NULL;
}
static void
node_editor_add(struct node_editor *editor, const char *name, struct nk_rect bounds,
struct nk_color col, int in_count, int out_count)
{
static int IDs = 0;
struct node *node;
assert((nk_size)editor->node_count < NK_LEN(editor->node_buf));
node = &editor->node_buf[editor->node_count++];
node->ID = IDs++;
node->value = 0;
node->color = nk_rgb(255, 0, 0);
node->input_count = in_count;
node->output_count = out_count;
node->color = col;
node->bounds = bounds;
strcpy(node->name, name);
node_editor_push(editor, node);
}
static void
node_editor_link(struct node_editor *editor, int in_id, int in_slot,
int out_id, int out_slot)
{
struct node_link *link;
assert((nk_size)editor->link_count < NK_LEN(editor->links));
link = &editor->links[editor->link_count++];
link->input_id = in_id;
link->input_slot = in_slot;
link->output_id = out_id;
link->output_slot = out_slot;
}
static void
node_editor_init(struct node_editor *editor)
{
memset(editor, 0, sizeof(*editor));
editor->begin = NULL;
editor->end = NULL;
node_editor_add(editor, "Source", nk_rect(40, 10, 180, 220), nk_rgb(255, 0, 0), 0, 1);
node_editor_add(editor, "Source", nk_rect(40, 260, 180, 220), nk_rgb(0, 255, 0), 0, 1);
node_editor_add(editor, "Combine", nk_rect(400, 100, 180, 220), nk_rgb(0,0,255), 2, 2);
node_editor_link(editor, 0, 0, 2, 0);
node_editor_link(editor, 1, 0, 2, 1);
editor->show_grid = nk_true;
}
static int
node_editor(struct nk_context *ctx)
{
int n = 0;
struct nk_rect total_space;
const struct nk_input *in = &ctx->input;
struct nk_command_buffer *canvas;
struct node *updated = 0;
struct node_editor *nodedit = &nodeEditor;
if (!nodeEditor.initialized) {
node_editor_init(&nodeEditor);
nodeEditor.initialized = 1;
}
if (nk_begin(ctx, "NodeEdit", nk_rect(0, 0, 800, 600),
NK_WINDOW_BORDER|NK_WINDOW_NO_SCROLLBAR|NK_WINDOW_MOVABLE|NK_WINDOW_CLOSABLE))
{
/* allocate complete window space */
canvas = nk_window_get_canvas(ctx);
total_space = nk_window_get_content_region(ctx);
nk_layout_space_begin(ctx, NK_STATIC, total_space.h, nodedit->node_count);
{
struct node *it = nodedit->begin;
struct nk_rect size = nk_layout_space_bounds(ctx);
struct nk_panel *node = 0;
if (nodedit->show_grid) {
/* display grid */
float x, y;
const float grid_size = 32.0f;
const struct nk_color grid_color = nk_rgb(50, 50, 50);
for (x = (float)fmod(size.x - nodedit->scrolling.x, grid_size); x < size.w; x += grid_size)
nk_stroke_line(canvas, x+size.x, size.y, x+size.x, size.y+size.h, 1.0f, grid_color);
for (y = (float)fmod(size.y - nodedit->scrolling.y, grid_size); y < size.h; y += grid_size)
nk_stroke_line(canvas, size.x, y+size.y, size.x+size.w, y+size.y, 1.0f, grid_color);
}
/* execute each node as a movable group */
while (it) {
/* calculate scrolled node window position and size */
nk_layout_space_push(ctx, nk_rect(it->bounds.x - nodedit->scrolling.x,
it->bounds.y - nodedit->scrolling.y, it->bounds.w, it->bounds.h));
/* execute node window */
if (nk_group_begin(ctx, it->name, NK_WINDOW_MOVABLE|NK_WINDOW_NO_SCROLLBAR|NK_WINDOW_BORDER|NK_WINDOW_TITLE))
{
/* always have last selected node on top */
node = nk_window_get_panel(ctx);
if (nk_input_mouse_clicked(in, NK_BUTTON_LEFT, node->bounds) &&
(!(it->prev && nk_input_mouse_clicked(in, NK_BUTTON_LEFT,
nk_layout_space_rect_to_screen(ctx, node->bounds)))) &&
nodedit->end != it)
{
updated = it;
}
/* ================= NODE CONTENT =====================*/
nk_layout_row_dynamic(ctx, 25, 1);
nk_button_color(ctx, it->color);
it->color.r = (nk_byte)nk_propertyi(ctx, "#R:", 0, it->color.r, 255, 1,1);
it->color.g = (nk_byte)nk_propertyi(ctx, "#G:", 0, it->color.g, 255, 1,1);
it->color.b = (nk_byte)nk_propertyi(ctx, "#B:", 0, it->color.b, 255, 1,1);
it->color.a = (nk_byte)nk_propertyi(ctx, "#A:", 0, it->color.a, 255, 1,1);
/* ====================================================*/
nk_group_end(ctx);
}
{
/* node connector and linking */
float space;
struct nk_rect bounds;
bounds = nk_layout_space_rect_to_local(ctx, node->bounds);
bounds.x += nodedit->scrolling.x;
bounds.y += nodedit->scrolling.y;
it->bounds = bounds;
/* output connector */
space = node->bounds.h / (float)((it->output_count) + 1);
for (n = 0; n < it->output_count; ++n) {
struct nk_rect circle;
circle.x = node->bounds.x + node->bounds.w-4;
circle.y = node->bounds.y + space * (float)(n+1);
circle.w = 8; circle.h = 8;
nk_fill_circle(canvas, circle, nk_rgb(100, 100, 100));
/* start linking process */
if (nk_input_has_mouse_click_down_in_rect(in, NK_BUTTON_LEFT, circle, nk_true)) {
nodedit->linking.active = nk_true;
nodedit->linking.node = it;
nodedit->linking.input_id = it->ID;
nodedit->linking.input_slot = n;
}
/* draw curve from linked node slot to mouse position */
if (nodedit->linking.active && nodedit->linking.node == it &&
nodedit->linking.input_slot == n) {
struct nk_vec2 l0 = nk_vec2(circle.x + 3, circle.y + 3);
struct nk_vec2 l1 = in->mouse.pos;
nk_stroke_curve(canvas, l0.x, l0.y, l0.x + 50.0f, l0.y,
l1.x - 50.0f, l1.y, l1.x, l1.y, 1.0f, nk_rgb(100, 100, 100));
}
}
/* input connector */
space = node->bounds.h / (float)((it->input_count) + 1);
for (n = 0; n < it->input_count; ++n) {
struct nk_rect circle;
circle.x = node->bounds.x-4;
circle.y = node->bounds.y + space * (float)(n+1);
circle.w = 8; circle.h = 8;
nk_fill_circle(canvas, circle, nk_rgb(100, 100, 100));
if (nk_input_is_mouse_released(in, NK_BUTTON_LEFT) &&
nk_input_is_mouse_hovering_rect(in, circle) &&
nodedit->linking.active && nodedit->linking.node != it) {
nodedit->linking.active = nk_false;
node_editor_link(nodedit, nodedit->linking.input_id,
nodedit->linking.input_slot, it->ID, n);
}
}
}
it = it->next;
}
/* reset linking connection */
if (nodedit->linking.active && nk_input_is_mouse_released(in, NK_BUTTON_LEFT)) {
nodedit->linking.active = nk_false;
nodedit->linking.node = NULL;
fprintf(stdout, "linking failed\n");
}
/* draw each link */
for (n = 0; n < nodedit->link_count; ++n) {
struct node_link *link = &nodedit->links[n];
struct node *ni = node_editor_find(nodedit, link->input_id);
struct node *no = node_editor_find(nodedit, link->output_id);
float spacei = node->bounds.h / (float)((ni->output_count) + 1);
float spaceo = node->bounds.h / (float)((no->input_count) + 1);
struct nk_vec2 l0 = nk_layout_space_to_screen(ctx,
nk_vec2(ni->bounds.x + ni->bounds.w, 3.0f + ni->bounds.y + spacei * (float)(link->input_slot+1)));
struct nk_vec2 l1 = nk_layout_space_to_screen(ctx,
nk_vec2(no->bounds.x, 3.0f + no->bounds.y + spaceo * (float)(link->output_slot+1)));
l0.x -= nodedit->scrolling.x;
l0.y -= nodedit->scrolling.y;
l1.x -= nodedit->scrolling.x;
l1.y -= nodedit->scrolling.y;
nk_stroke_curve(canvas, l0.x, l0.y, l0.x + 50.0f, l0.y,
l1.x - 50.0f, l1.y, l1.x, l1.y, 1.0f, nk_rgb(100, 100, 100));
}
if (updated) {
/* reshuffle nodes to have least recently selected node on top */
node_editor_pop(nodedit, updated);
node_editor_push(nodedit, updated);
}
/* node selection */
if (nk_input_mouse_clicked(in, NK_BUTTON_LEFT, nk_layout_space_bounds(ctx))) {
it = nodedit->begin;
nodedit->selected = NULL;
nodedit->bounds = nk_rect(in->mouse.pos.x, in->mouse.pos.y, 100, 200);
while (it) {
struct nk_rect b = nk_layout_space_rect_to_screen(ctx, it->bounds);
b.x -= nodedit->scrolling.x;
b.y -= nodedit->scrolling.y;
if (nk_input_is_mouse_hovering_rect(in, b))
nodedit->selected = it;
it = it->next;
}
}
/* contextual menu */
if (nk_contextual_begin(ctx, 0, nk_vec2(100, 220), nk_window_get_bounds(ctx))) {
const char *grid_option[] = {"Show Grid", "Hide Grid"};
nk_layout_row_dynamic(ctx, 25, 1);
if (nk_contextual_item_label(ctx, "New", NK_TEXT_CENTERED))
node_editor_add(nodedit, "New", nk_rect(400, 260, 180, 220),
nk_rgb(255, 255, 255), 1, 2);
if (nk_contextual_item_label(ctx, grid_option[nodedit->show_grid],NK_TEXT_CENTERED))
nodedit->show_grid = !nodedit->show_grid;
nk_contextual_end(ctx);
}
}
nk_layout_space_end(ctx);
/* window content scrolling */
if (nk_input_is_mouse_hovering_rect(in, nk_window_get_bounds(ctx)) &&
nk_input_is_mouse_down(in, NK_BUTTON_MIDDLE)) {
nodedit->scrolling.x += in->mouse.delta.x;
nodedit->scrolling.y += in->mouse.delta.y;
}
}
nk_end(ctx);
return !nk_window_is_closed(ctx, "NodeEdit");
}