From a4f0540210d728c34d71ad985b48aafde3431445 Mon Sep 17 00:00:00 2001
From: Carlos Sanchez <randomouscrap98@aol.com>
Date: Fri, 16 Aug 2024 04:30:28 -0400
Subject: [PATCH] Maze generation!

---
 haloo3d |  2 +-
 maze.c  | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 79 insertions(+), 9 deletions(-)

diff --git a/haloo3d b/haloo3d
index 11f20ce..7753972 160000
--- a/haloo3d
+++ b/haloo3d
@@ -1 +1 @@
-Subproject commit 11f20ce5e2b3053ce777151928500be797f3893f
+Subproject commit 775397220d63a5f92ad1ad16c0409c515ce13c30
diff --git a/maze.c b/maze.c
index e2b6e24..c9c7fa3 100644
--- a/maze.c
+++ b/maze.c
@@ -34,6 +34,79 @@
 #define MAZESIZE 31
 #define HSCALE 2.0
 
+// Generate a (square) maze
+void gen_maze(haloo3d_obj *mazewalls, int size) {
+  uint8_t *mazevisit;
+  int *mazestack;
+  mallocordie(mazevisit, sizeof(uint8_t) * size * size);
+  mallocordie(mazestack, sizeof(int) * size * size);
+  memset(mazevisit, 0, size * size);
+  for (int i = 0; i < size * size; i++) {
+    mazestack[i] = -1;
+  }
+
+  // Push current cell onto stack, mark as visited
+  int x = size / 2;
+  int y = size / 2;
+  mazevisit[x + y * size] = 1;
+  mazestack[0] = x + y * size;
+  int mazetop = 1;
+  struct vec2i visitable[4];
+  int visitmax = 0;
+
+  // Now let's make a maze!
+  while (mazetop) {
+    mazetop--;
+    visitmax = 0;
+    x = mazestack[mazetop] % size;
+    y = mazestack[mazetop] / size;
+    if (x > 0 && !mazevisit[x - 1 + y * size]) {
+      visitable[visitmax].x = -1;
+      visitable[visitmax++].y = 0;
+    }
+    if (x < size - 1 && !mazevisit[x + 1 + y * size]) {
+      visitable[visitmax].x = 1;
+      visitable[visitmax++].y = 0;
+    }
+    if (y > 0 && !mazevisit[x + (y - 1) * size]) {
+      visitable[visitmax].x = 0;
+      visitable[visitmax++].y = -1;
+    }
+    if (y < size - 1 && !mazevisit[x + (y + 1) * size]) {
+      visitable[visitmax].x = 0;
+      visitable[visitmax++].y = 1;
+    }
+    // You can generate a random location!
+    if (visitmax) {
+      mazetop++; // mazestack already has our location
+      struct vec2i movedir = visitable[rand() % visitmax];
+      int facebase = 4 * (x + y * size);
+      // Faces are... somewhere.
+      haloo3d_vertexi *face; // This is actually 6 vertices, the quad
+      // Only y == -21 moves in the direction of facebase
+      if (movedir.y == 1) {
+        facebase += 4 * size; // backwards?
+      } else if (movedir.x == -1) {
+        facebase += 2;
+      } else if (movedir.x == 1) {
+        facebase += 6;
+      }
+      face = mazewalls->faces[facebase];
+      for (int i = 0; i < 6; i++) {
+        face[i].posi = 0; // this should make the triangles degenerate
+      }
+      int nx = x + movedir.x;
+      int ny = y + movedir.y;
+      // Push onto stack and set visited
+      mazestack[mazetop++] = nx + ny * size;
+      mazevisit[nx + ny * size] = 1;
+    }
+  }
+
+  free(mazevisit);
+  free(mazestack);
+}
+
 int main() { // int argc, char **argv) {
 
   haloo3d_easystore storage;
@@ -69,6 +142,7 @@ int main() { // int argc, char **argv) {
   haloo3d_gen_plane(flooro, MAZESIZE);
   haloo3d_gen_plane(ceilo, MAZESIZE);
   haloo3d_gen_grid(wallo, MAZESIZE);
+  gen_maze(wallo, MAZESIZE);
 
   uint16_t cols[4] = {0xFD93, 0xFB83, 0xFEEE, 0xFDDD};
   haloo3d_fb_init_tex(floort, 64, 64);
@@ -107,7 +181,7 @@ int main() { // int argc, char **argv) {
   vec3(floori->scale.v, HSCALE, 1, HSCALE);
   vec3(ceili->scale.v, HSCALE, 1, HSCALE);
   vec3(walli->scale.v, HSCALE, 0, HSCALE);
-  ceili->pos.y = 1;
+  ceili->pos.y = 1; //-1;
   eprintf("Setup all object instances\n");
 
   unigi_type_event event;
@@ -126,6 +200,9 @@ int main() { // int argc, char **argv) {
   unigi_graphics_init();
   unigi_window_create(res, "maze.exe"); // render.printbuf);
 
+  // render.camera.pos.y = 5;
+  // render.camera.pitch = 2.2;
+
   // -----------------------------------
   //     Actual rendering
   // -----------------------------------
@@ -137,13 +214,6 @@ int main() { // int argc, char **argv) {
     render.camera.yaw += 0.008;
     haloo3d_easyrender_beginframe(&render);
     haloo3d_fb_clear(&render.window, 0xF000);
-    // memset(render.window.buffer, 0,
-    //      sizeof(uint16_t) * render.window.width * render.window.height);
-
-    // for (int j = 0; j < 100; j++) {
-    //   ceilt->buffer[rand() % (ceilt->width * ceilt->height)] =
-    //       0xF000 | (rand() & 0xFFF);
-    // }
 
     walli->scale.y = fabs(sin(3 * render.camera.yaw));
     // render.camera.up.x = sin(render.camera.yaw);