Update node struct to know about noodle connected to it

.gitignore

@@ -1,3 +1,4 @@
 .cache
 compile_commands.json
 main
+*.dSYM

compile

@@ -8,7 +8,7 @@ INCLUDE="\
 	-Iintern/wizapp/aliases \
 	-Iintern/wizapp/cpath/include \
 	-Iintern/wizapp/dstr/include \
-	$(find intern/wizapp/mem/include/ -type d | xargs -I{} printf "-I{} ") \
+	$(find intern/wizapp/mem/include -type d | xargs -I{} echo -n "-I{} ") \
 "
 SRC="\
 	intern/wizapp/cpath/src/*.c \

include/nodes.h

@@ -7,11 +7,15 @@
 #define MAX_NODES 1024
 #define IO_INPUT_COUNT 0
 #define OP_INPUT_COUNT 2
+#define EMPTY_NODE 0
+#define NODE_START 1
+#define CONNECTION_START 1
 
 typedef i32 (*node_func)(i32 a, i32 b);
 typedef enum node_type node_type;
 typedef union node_data node_data;
 typedef struct node node;
+typedef struct noodle noodle;
 
 enum node_type {
   NODE_TYPE_IO,
@@ -25,13 +29,21 @@ union node_data {
   node_func func;
 };
 
+struct noodle {
+  line ln;
+  u64 connected_node;
+  u64 connection_idx;
+};
+
 struct node {
   rect rec;
   ui_elem_colours colours;
   node_type type;
   node_data data;
   u64 inputs;
-  line *noodles;
+  u64 connected;
+  noodle *noodles;
+  noodle **connected_noodles;
 };
 
 #endif // !NODES_H

include/ui.h

@@ -7,8 +7,6 @@
 #include <stdbool.h>
 
 #define MAX_UI_ELEMENTS 8192
-#define RESERVED_UI_SLOT 0
-#define UI_ELEM_START_INDEX 1
 
 #define BUTTON_WIDTH 100
 #define BUTTON_HEIGHT 40
@@ -21,6 +19,8 @@
 typedef enum ui_elem_type ui_elem_type;
 typedef struct ui_elem ui_elem;
 typedef struct ui_ctx ui_ctx;
+typedef struct ui_elem_colours ui_elem_colours;
+typedef enum noodle_action noodle_action;
 
 enum ui_elem_type {
   UI_ELEM_NODE,
@@ -39,12 +39,17 @@ struct ui_elem {
   ui_elem_type type;
 };
 
-typedef struct ui_elem_colours ui_elem_colours;
 struct ui_elem_colours {
   colour fill;
   colour border;
 };
 
+enum noodle_action {
+  NOODLE_ACTION_NONE,
+  NOODLE_ACTION_DRAGGING,
+  NOODLE_ACTION_RELEASED,
+};
+
 struct ui_ctx {
   u64 count;
   i64 hovered;
@@ -66,7 +71,7 @@ bool ui_button(const window *wnd, ui_ctx *ctx, rect rect,
                ui_elem_colours colours);
 bool ui_node(const window *wnd, ui_ctx *ctx, rect rect,
              ui_elem_colours colours);
-bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
-               rect parent_node);
+noodle_action ui_noodle(const window *wnd, ui_ctx *ctx, line ln,
+                        ui_elem_colours colours, rect parent_node);
 
 #endif // !UI_H

src/compositor.c

@@ -9,7 +9,6 @@
 #include <SDL2/SDL_render.h>
 #include <SDL2/SDL_video.h>
 #include <stdbool.h>
-#include <stdio.h>
 #include <stdlib.h>
 
 #define MAX_WINDOWS 2
@@ -26,15 +25,16 @@ struct compositor {
   u32 active_window;
   SDL_Event event;
   bool running;
-  i64 node_hovered;
   u64 count;
   node *nodes;
-  bool move_node;
+  node *back_nodes;
   ui_ctx ctx;
 };
 
-void add_node(compositor *comp, node_type type, node_data data, u64 inputs,
-              i32 x, i32 y, ui_elem_colours colours);
+internal void add_node(compositor *comp, node_type type, node_data data,
+                       u64 inputs, i32 x, i32 y, ui_elem_colours colours);
+internal void update_node_graph(compositor *comp, const window *wnd);
+internal void draw_node_graph(compositor *comp, const window *wnd);
 
 i32 run_main_loop(void) {
   if (SDL_Init(SDL_INIT_EVERYTHING) != 0) {
@@ -47,6 +47,8 @@ i32 run_main_loop(void) {
   mem_arena_init(&comp.arena, ARENA_CAPACITY);
 
   comp.nodes = (node *)mem_arena_alloc(comp.arena, sizeof(node) * MAX_NODES);
+  comp.back_nodes =
+      (node *)mem_arena_alloc(comp.arena, sizeof(node) * MAX_NODES);
 
   window *main_window = &(comp.windows[0]);
   window *toolbox = &(comp.windows[1]);
@@ -87,16 +89,16 @@ i32 run_main_loop(void) {
       handle_ui_events(&(comp.windows[comp.active_window - 1]), &(comp.ctx),
                        &(comp.event));
 
-      switch (comp.event.type) {
-      case SDL_QUIT:
+      if (comp.event.type == SDL_QUIT) {
         comp.running = false;
-        break;
-      case SDL_WINDOWEVENT:
-        switch (comp.event.window.event) {
-        case SDL_WINDOWEVENT_CLOSE:
+      }
+
+      if (comp.event.type == SDL_WINDOWEVENT) {
+        if (comp.event.window.event == SDL_WINDOWEVENT_CLOSE) {
           comp.running = false;
-          break;
-        case SDL_WINDOWEVENT_ENTER: {
+        }
+
+        if (comp.event.window.event == SDL_WINDOWEVENT_ENTER) {
           u32 id = comp.event.window.windowID;
           window *wnd = NULL;
 
@@ -110,29 +112,24 @@ i32 run_main_loop(void) {
             }
           }
 
-          if (!wnd) {
-            break;
+          if (wnd) {
+            SDL_RaiseWindow(wnd->window);
           }
-
-          SDL_RaiseWindow(wnd->window);
-
-          break;
-        }
         }
+      }
 
-        break;
-      case SDL_DROPFILE:
+      if (comp.event.type == SDL_DROPFILE) {
         if (comp.event.drop.windowID == main_window->id) {
           node_data data = (node_data){.path = comp.event.drop.file};
 
           add_node(&comp, NODE_TYPE_IO, data, IO_INPUT_COUNT, comp.ctx.mouse_x,
                    comp.ctx.mouse_y, io_node_colours);
-
-          break;
         }
       }
     }
 
+    update_node_graph(&comp, main_window);
+
     for (u64 i = 0; i < MAX_WINDOWS; ++i) {
       clear_window(&(comp.windows[i]), bg_colour);
     }
@@ -153,56 +150,7 @@ i32 run_main_loop(void) {
       }
     }
 
-    for (u64 i = 0; i < comp.count; ++i) {
-      node *node_elem = &(comp.nodes[i]);
-
-      f64 angle = 90.0;
-      f64 angle_delta = 25.0;
-      i64 delta_multiplier = node_elem->inputs % 2 == 0 ? -1 : 0;
-
-      for (u64 j = 0; j < comp.nodes[i].inputs; ++j) {
-        f64 new_angle = angle + angle_delta * delta_multiplier;
-        line *ln = &(node_elem->noodles[j]);
-
-        if (ln->p0.x == ln->p1.x && ln->p0.y == ln->p1.y) {
-          point origin = {node_elem->rec.topleft.x + node_elem->rec.w / 2,
-                          node_elem->rec.topleft.y + node_elem->rec.h / 2};
-
-          *ln = line_from_origin(origin, new_angle, DEFAULT_NOODLE_LENGTH);
-        }
-
-        if (ui_noodle(main_window, &(comp.ctx), *ln, node_elem->colours,
-                      node_elem->rec)) {
-          ln->p0.x += comp.ctx.rel_x;
-          ln->p0.y += comp.ctx.rel_y;
-        }
-
-        if (delta_multiplier > 0) {
-          angle = new_angle;
-        }
-
-        if (delta_multiplier == 0) {
-          delta_multiplier = -1;
-        } else {
-          delta_multiplier *= -1;
-        }
-      }
-
-      if (ui_node(main_window, &(comp.ctx), node_elem->rec,
-                  node_elem->colours)) {
-        node_elem->rec.topleft.x += comp.ctx.rel_x;
-        node_elem->rec.topleft.y += comp.ctx.rel_y;
-
-        for (u64 j = 0; j < comp.nodes[i].inputs; ++j) {
-          line *ln = &(node_elem->noodles[j]);
-
-          ln->p0.x += comp.ctx.rel_x;
-          ln->p0.y += comp.ctx.rel_y;
-          ln->p1.x += comp.ctx.rel_x;
-          ln->p1.y += comp.ctx.rel_y;
-        }
-      }
-    }
+    draw_node_graph(&comp, main_window);
 
     for (u64 i = 0; i < MAX_WINDOWS; ++i) {
       swap_buffers(&(comp.windows[i]));
@@ -222,15 +170,25 @@ i32 run_main_loop(void) {
   return EXIT_SUCCESS;
 }
 
-void add_node(compositor *comp, node_type type, node_data data, u64 inputs,
-              i32 x, i32 y, ui_elem_colours colours) {
+internal void add_node(compositor *comp, node_type type, node_data data,
+                       u64 inputs, i32 x, i32 y, ui_elem_colours colours) {
   if (comp->count + 1 >= MAX_NODES) {
     return;
   }
 
-  u64 alloc_size = inputs * sizeof(line);
-  line *noodles = mem_arena_alloc(comp->arena, alloc_size);
-  if (!noodles) {
+  u64 alloc_size = inputs * sizeof(noodle);
+  noodle *noodles = mem_arena_alloc(comp->arena, alloc_size);
+  noodle *back_noodles = mem_arena_alloc(comp->arena, alloc_size);
+  if (!noodles || !back_noodles) {
+    return;
+  }
+
+  u64 connected_alloc_size = MAX_NODES * sizeof(noodle *);
+  noodle **connected_noodles =
+      mem_arena_alloc(comp->arena, connected_alloc_size);
+  noodle **connected_back_noodles =
+      mem_arena_alloc(comp->arena, connected_alloc_size);
+  if (!connected_noodles || !connected_back_noodles) {
     return;
   }
 
@@ -241,12 +199,174 @@ void add_node(compositor *comp, node_type type, node_data data, u64 inputs,
       .h = NODE_HEIGHT,
   };
 
-  comp->nodes[(comp->count)++] = (node){
+  u64 idx = ++(comp->count);
+
+  comp->nodes[idx] = comp->back_nodes[idx] = (node){
       .rec = rec,
       .colours = colours,
       .type = type,
       .data.path = data.path,
       .inputs = inputs,
+      .connected = 0,
       .noodles = noodles,
+      .connected_noodles = connected_noodles,
   };
+
+  comp->back_nodes[idx].noodles = back_noodles;
+  comp->back_nodes[idx].connected_noodles = connected_back_noodles;
+}
+
+internal void update_node_graph(compositor *comp, const window *wnd) {
+  for (u64 i = NODE_START; i <= comp->count; ++i) {
+    node *node_elem = &(comp->nodes[i]);
+    const node *back_node = &(comp->back_nodes[i]);
+
+    node_elem->rec = back_node->rec;
+    node_elem->connected = back_node->connected;
+
+    for (u64 j = 0; j < node_elem->inputs; ++j) {
+      noodle *ndl = &(node_elem->noodles[j]);
+      const noodle *back_ndl = &(back_node->noodles[j]);
+
+      *ndl = *back_ndl;
+    }
+
+    for (u64 j = CONNECTION_START; j <= back_node->connected; ++j) {
+      node_elem->connected_noodles[j] = back_node->connected_noodles[j];
+    }
+  }
+}
+
+internal void draw_node_graph(compositor *comp, const window *wnd) {
+  for (u64 i = NODE_START; i <= comp->count; ++i) {
+    node *node_elem = &(comp->nodes[i]);
+    node *back_node = &(comp->back_nodes[i]);
+
+    f64 angle = 90.0;
+    f64 angle_delta = 25.0;
+    i64 delta_multiplier = node_elem->inputs % 2 == 0 ? -1 : 0;
+
+    for (u64 j = 0; j < node_elem->inputs; ++j) {
+      f64 new_angle = angle + angle_delta * delta_multiplier;
+      noodle *ndl = &(node_elem->noodles[j]);
+      noodle *back_ndl = &(back_node->noodles[j]);
+
+      if (ndl->ln.p0.x == ndl->ln.p1.x && ndl->ln.p0.y == ndl->ln.p1.y) {
+        point origin = {node_elem->rec.topleft.x + node_elem->rec.w / 2,
+                        node_elem->rec.topleft.y + node_elem->rec.h / 2};
+
+        back_ndl->ln =
+            line_from_origin(origin, new_angle, DEFAULT_NOODLE_LENGTH);
+      }
+
+      switch (ui_noodle(wnd, &(comp->ctx), ndl->ln, node_elem->colours,
+                        node_elem->rec)) {
+      case NOODLE_ACTION_DRAGGING:
+        back_ndl->ln.p0.x += comp->ctx.rel_x;
+        back_ndl->ln.p0.y += comp->ctx.rel_y;
+        break;
+      case NOODLE_ACTION_RELEASED: {
+        bool connected = false;
+        bool disconnect = false;
+
+        for (u64 k = NODE_START; k <= comp->count; ++k) {
+          if (k == i) {
+            continue;
+          }
+
+          const node *nd = &(comp->nodes[k]);
+          node *back_node = &(comp->back_nodes[k]);
+
+          if (aabb(nd->rec, comp->ctx.mouse_x, comp->ctx.mouse_y)) {
+            point p0 = {nd->rec.topleft.x + nd->rec.w / 2,
+                        nd->rec.topleft.y + nd->rec.h / 2};
+
+            back_ndl->ln.p0 = p0;
+
+            connected = true;
+            disconnect = back_ndl->connected_node != EMPTY_NODE &&
+                         back_ndl->connected_node != k;
+
+            if (back_ndl->connected_node != k) {
+              back_ndl->connected_node = k;
+              u64 idx = ++(back_node->connected);
+              back_ndl->connection_idx = idx;
+              back_node->connected_noodles[idx] = back_ndl;
+            }
+
+            break;
+          } else {
+            if (back_ndl->connected_node != EMPTY_NODE) {
+              disconnect = true;
+            }
+          }
+        }
+
+        if (disconnect) {
+          u64 conntection_idx = back_ndl->connection_idx;
+          u64 node_idx = back_ndl->connected_node;
+
+          node *connected_node = &(comp->back_nodes[node_idx]);
+
+          if (conntection_idx == connected_node->connected) {
+            connected_node->connected_noodles[conntection_idx] = NULL;
+          } else {
+            connected_node->connected_noodles[conntection_idx] =
+                connected_node->connected_noodles[connected_node->connected];
+            connected_node->connected_noodles[connected_node->connected] = NULL;
+
+            connected_node->connected_noodles[conntection_idx]->connection_idx =
+                conntection_idx;
+          }
+
+          connected_node->connected -= 1;
+        }
+
+        if (!connected) {
+          back_ndl->ln.p0 = ndl->ln.p1;
+          back_ndl->connected_node = EMPTY_NODE;
+        }
+
+        break;
+      }
+      default:
+        break;
+      }
+
+      if (delta_multiplier > 0) {
+        angle = new_angle;
+      }
+
+      if (delta_multiplier == 0) {
+        delta_multiplier = -1;
+      } else {
+        delta_multiplier *= -1;
+      }
+    }
+
+    if (ui_node(wnd, &(comp->ctx), node_elem->rec, node_elem->colours)) {
+      back_node->rec.topleft.x += comp->ctx.rel_x;
+      back_node->rec.topleft.y += comp->ctx.rel_y;
+
+      for (u64 j = 0; j < node_elem->inputs; ++j) {
+        noodle *ndl = &(node_elem->noodles[j]);
+        noodle *back_ndl = &(back_node->noodles[j]);
+
+        if (ndl->connected_node == EMPTY_NODE) {
+          back_ndl->ln.p0.x += comp->ctx.rel_x;
+          back_ndl->ln.p0.y += comp->ctx.rel_y;
+        }
+
+        back_ndl->ln.p1.x += comp->ctx.rel_x;
+        back_ndl->ln.p1.y += comp->ctx.rel_y;
+      }
+
+      for (u64 j = CONNECTION_START; j <= back_node->connected; ++j) {
+        noodle *ndl = back_node->connected_noodles[j];
+
+        ndl->ln.p0.x += comp->ctx.rel_x;
+        ndl->ln.p0.y += comp->ctx.rel_y;
+      }
+    }
+  }
 }

src/ui.c

@@ -26,34 +26,31 @@ void reset_ui_ctx(ui_ctx *ctx) {
 }
 
 void handle_ui_events(const window *wnd, ui_ctx *ctx, const SDL_Event *event) {
-  switch (event->type) {
-  case SDL_MOUSEMOTION:
+  if (event->type == SDL_MOUSEMOTION) {
     if (wnd->id == event->motion.windowID) {
       ctx->mouse_x = event->motion.x;
       ctx->mouse_y = event->motion.y;
       ctx->rel_x += event->motion.xrel;
       ctx->rel_y += event->motion.yrel;
       ctx->wnd = wnd;
-
-      break;
     }
-  case SDL_MOUSEBUTTONDOWN:
+  }
+
+  if (event->type == SDL_MOUSEBUTTONDOWN) {
     if (wnd->id == event->button.windowID) {
       ctx->mouse_x = event->button.x;
       ctx->mouse_y = event->button.y;
       ctx->mouse_down = true;
       ctx->wnd = wnd;
-
-      break;
     }
-  case SDL_MOUSEBUTTONUP:
+  }
+
+  if (event->type == SDL_MOUSEBUTTONUP) {
     if (wnd->id == event->button.windowID) {
       ctx->mouse_x = event->button.x;
       ctx->mouse_y = event->button.y;
       ctx->mouse_up = true;
       ctx->wnd = wnd;
-
-      break;
     }
   }
 }
@@ -141,10 +138,10 @@ bool ui_node(const window *wnd, ui_ctx *ctx, rect rect,
   return false;
 }
 
-bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
-               rect parent_node) {
+noodle_action ui_noodle(const window *wnd, ui_ctx *ctx, line ln,
+                        ui_elem_colours colours, rect parent_node) {
   if (ctx->count + 1 >= MAX_UI_ELEMENTS) {
-    return false;
+    return NOODLE_ACTION_NONE;
   }
 
   u64 id = get_id(ctx);
@@ -220,24 +217,25 @@ bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
   }
 
   if (wnd != ctx->wnd || (ctx->active >= 0 && ctx->active != id)) {
-    return false;
+    return NOODLE_ACTION_NONE;
   }
 
   if (ctx->mouse_up) {
     if (ctx->hovered == ctx->active && ctx->hovered == id) {
       ctx->hovered = ctx->active = -1;
+      return NOODLE_ACTION_RELEASED;
     }
 
-    return true;
+    return NOODLE_ACTION_NONE;
   }
 
   if (ctx->hovered == id && ctx->active == id) {
-    return true;
+    return NOODLE_ACTION_DRAGGING;
   }
 
   if (!aabb(bounding_box, ctx->mouse_x, ctx->mouse_y) ||
       aabb(parent_node, ctx->mouse_x, ctx->mouse_y)) {
-    return false;
+    return NOODLE_ACTION_NONE;
   }
 
   ctx->hovered = id;
@@ -246,7 +244,7 @@ bool ui_noodle(const window *wnd, ui_ctx *ctx, line ln, ui_elem_colours colours,
     ctx->active = id;
   }
 
-  return false;
+  return NOODLE_ACTION_NONE;
 }
 
 internal u64 get_id(ui_ctx *ctx) {