diff --git a/.vscode/settings.json b/.vscode/settings.json
index ae64e74..d909400 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -7,6 +7,7 @@
         "display.h": "c",
         "generation.h": "c",
         "time.h": "c",
-        "limits": "c"
+        "limits": "c",
+        "sdl.h": "c"
     }
 }
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 921b2a7..0dd55f0 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ all: bin/back
 test: bin/back
 	bin/back
 
-bin/back: obj/main.o obj/generation.o obj/display.o obj/entities.o obj/move.o obj/base.o obj/hash.o
+bin/back: obj/main.o obj/generation.o obj/display.o obj/entities.o obj/triangles.o obj/move.o obj/base.o obj/hash.o
 	mkdir -p bin
 	$(CC) $(FLAGS) $^ $(LFLAGS) -o $@
 
@@ -19,6 +19,7 @@ obj/main.o: src/main.c
 obj/generation.o: src/generation.c
 obj/display.o: src/display.c
 obj/entities.o: src/entities.c
+obj/triangles.o: src/triangles.c
 obj/move.o: src/move.c
 obj/base.o: src/base.c
 obj/hash.o: src/hash.c
diff --git a/bin/back b/bin/back
index 1987dd2..8907ee6 100755
Binary files a/bin/back and b/bin/back differ
diff --git a/obj/base.o b/obj/base.o
index dd1cc78..ef60ff1 100644
Binary files a/obj/base.o and b/obj/base.o differ
diff --git a/obj/display.o b/obj/display.o
index 6878eac..5fe5fd5 100644
Binary files a/obj/display.o and b/obj/display.o differ
diff --git a/obj/entities.o b/obj/entities.o
index e2656c1..63a0e5e 100644
Binary files a/obj/entities.o and b/obj/entities.o differ
diff --git a/obj/generation.o b/obj/generation.o
index 2773848..87bbab4 100644
Binary files a/obj/generation.o and b/obj/generation.o differ
diff --git a/obj/hash.o b/obj/hash.o
index 0808bd8..59edf79 100644
Binary files a/obj/hash.o and b/obj/hash.o differ
diff --git a/obj/main.o b/obj/main.o
index 075c34f..88b382c 100644
Binary files a/obj/main.o and b/obj/main.o differ
diff --git a/obj/move.o b/obj/move.o
index ce2a5fc..8f6b7c1 100644
Binary files a/obj/move.o and b/obj/move.o differ
diff --git a/obj/triangles.o b/obj/triangles.o
new file mode 100644
index 0000000..c96df28
Binary files /dev/null and b/obj/triangles.o differ
diff --git a/src/base.c b/src/base.c
index 3792cc9..1eceaf3 100644
--- a/src/base.c
+++ b/src/base.c
@@ -297,6 +297,23 @@ double distance_pt_cube_3d(double x0, double y0, double z0, cube cb) {
     return distance_pt_cube_0_3d(x0, y0, z0, *cb) ;
 }
 
+void project_to_camera(double x0, double y0, double z0, double* rx, double* ry, double* rz) {
+    // align pt to (0, 0, 0)
+    double x = x0 - camx ;
+    double y = y0 - camy ;
+    double z = z0 - camz ;
+
+    // rotate (y)
+    double xry = x*cos(rot_hz) + z*sin(rot_hz) ;
+    double yry = y ;
+    double zry = z*cos(rot_hz) - x*sin(rot_hz) ;
+
+    // rotate (x)
+    if(rx != NULL) {*rx = xry ;}
+    if(ry != NULL) {*ry = yry*cos(rot_vt) - zry*sin(rot_vt) ;}
+    if(rz != NULL) {*rz = zry*cos(rot_vt) + yry*sin(rot_vt) ;}
+}
+
 // ------------------------------------------------------------------------------------------------ //
 
 void remove_entity(entity** arr, int* memlen, int* len, int index) {
diff --git a/src/base.h b/src/base.h
index d541b92..56d5023 100644
--- a/src/base.h
+++ b/src/base.h
@@ -48,6 +48,7 @@ void remove_entity(entity** arr, int* memlen, int* len, int index);
 void add_entity(entity** arr, int* memlen, int* len, entity ent);
 
 double distance_pt_cube_3d(double x0, double y0, double z0, cube cb);
+void project_to_camera(double x0, double y0, double z0, double* rx, double* ry, double* rz);
 
 void import_digits(SDL_Renderer* renderer);
 void import_letters(SDL_Renderer* renderer);
diff --git a/src/display.c b/src/display.c
index 9a5bbc3..41b24fa 100644
--- a/src/display.c
+++ b/src/display.c
@@ -14,6 +14,7 @@
 #include "hash.h"
 #include "structure.h"
 #include "base.h"
+#include "triangles.h"
 #include "move.h"
 #include "entities.h"
 #include "generation.h"
@@ -21,10 +22,11 @@
 
 int* drawOrder;
 
-double draw_constant = 0.4 ;
+double draw_constant ;
 
 void init_draworder() {
     drawOrder = malloc(sizeof(int)*6) ;
+    draw_constant = 0.4 ;
 }
 
 void updateRenderer(SDL_Renderer* renderer) {
@@ -168,25 +170,6 @@ void drawStringToRenderer(SDL_Renderer* renderer, imgs data, char* s, int X, int
 // ---------------------------------------------------------------------------------------------------------------------------------- //
 // 3D stuff
 
-void project_to_camera(double x0, double y0, double z0, double* rx, double* ry, double* rz) {
-    // align pt to (0, 0, 0)
-    double x = x0 - camx ;
-    double y = y0 - camy ;
-    double z = z0 - camz ;
-
-    // rotate (y)
-    double xry = x*cos(rot_hz) + z*sin(rot_hz) ;
-    double yry = y ;
-    double zry = z*cos(rot_hz) - x*sin(rot_hz) ;
-
-    // rotate (x)
-    if(rx != NULL) {*rx = xry ;}
-    if(ry != NULL) {*ry = yry*cos(rot_vt) - zry*sin(rot_vt) ;}
-    if(rz != NULL) {*rz = zry*cos(rot_vt) + yry*sin(rot_vt) ;}
-}
-
-// ---------------------------------------------------------------------------------------------------------------------------------- //
-
 double pt_z_distance_to_camera(double x, double y, double z) {
     double ret ;
     project_to_camera(x, y, z, NULL, NULL, &ret) ;
@@ -450,13 +433,6 @@ SDL_Vertex construct_vertex(double px, double py, int r, int g, int b) {
     return vtx ;
 }
 
-    double px0; double py0; double pz0;
-    double px1; double py1; double pz1;
-    double px2; double py2; double pz2;
-        double fpx0; double fpy0; double fpz0;
-        double fpx1; double fpy1; double fpz1;
-        double mpx0; double mpy0; double mpz0;
-        double mpx1; double mpy1; double mpz1;
 void renderTriangle(
     SDL_Renderer* renderer,
     double x0, double y0, double z0,
@@ -732,6 +708,23 @@ void drawCurrentRoom(SDL_Renderer* renderer) {
     insertionSort_tp(current_room->tps, current_room->tps_size);
     insertionSort_ent(current_room->ents, current_room->ent_len);
 
+    for(int k1 = 0; k1 < current_room->map_size; k1++) {
+        current_room->map[k1].red = 188 ;
+        current_room->map[k1].green = 0 ;
+        current_room->map[k1].blue = 0 ;
+    }
+
+    for(int k1 = 0; k1 < current_room->map_size; k1++) {
+        for(int k2 = k1+1; k2 < current_room->map_size; k2++) {
+            if(cubeOverlap(current_room->map[k1], current_room->map[k2])) {
+                current_room->map[k1].red = 0 ;
+                current_room->map[k1].green = 188 ;
+                current_room->map[k2].red = 0 ;
+                current_room->map[k2].green = 188 ;
+            }
+        }
+    }
+
     if(true || draw_type == 0) {
         for(int k = 0; k < current_room->map_size; k++) {
             drawFullCube(renderer, current_room->map[k]);
diff --git a/src/main.c b/src/main.c
index 206b5f4..41b4e26 100644
--- a/src/main.c
+++ b/src/main.c
@@ -54,6 +54,7 @@ int main(int argc, char** argv) {
     init_csts() ;
     init_hashtbl() ;
     init_draworder() ;
+    trInit();
     parse_rooms(3);
     import_digits(rend) ;
     import_letters(rend) ;
diff --git a/src/structure.h b/src/structure.h
index 20e7b6c..9a8bcb1 100644
--- a/src/structure.h
+++ b/src/structure.h
@@ -6,6 +6,12 @@ typedef struct imgs {
     SDL_Texture** arr;
 } imgs ;
 
+typedef struct pt_2d {
+    double x;
+    double y;
+    double z;
+} pt_2d ;
+
 struct cube_0 {
     int red; int green; int blue ;
     double x;
@@ -107,4 +113,14 @@ extern int coins ;
 
 extern int draw_type ;
 
+extern double draw_constant ;
+
+extern double px0; extern double py0; extern double pz0;
+extern double px1; extern double py1; extern double pz1;
+extern double px2; extern double py2; extern double pz2;
+extern double fpx0; extern double fpy0; extern double fpz0;
+extern double fpx1; extern double fpy1; extern double fpz1;
+extern double mpx0; extern double mpy0; extern double mpz0;
+extern double mpx1; extern double mpy1; extern double mpz1;
+
 #endif
\ No newline at end of file
diff --git a/src/triangles.c b/src/triangles.c
new file mode 100644
index 0000000..d8cf741
--- /dev/null
+++ b/src/triangles.c
@@ -0,0 +1,346 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <math.h>
+#include <stdbool.h>
+#include <ncurses.h>
+#include <unistd.h>
+#include <termios.h>
+#include <limits.h>
+#include <time.h>
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_image.h>
+
+#include "hash.h"
+#include "structure.h"
+#include "base.h"
+#include "triangles.h"
+
+double px0; double py0; double pz0;
+double px1; double py1; double pz1;
+double px2; double py2; double pz2;
+double fpx0; double fpy0; double fpz0;
+double fpx1; double fpy1; double fpz1;
+double mpx0; double mpy0; double mpz0;
+double mpx1; double mpy1; double mpz1;
+
+int errno = 0;
+pt_2d* triangle_1 ;
+pt_2d* triangle_2 ;
+
+pt_2d* cube_t1 ;
+pt_2d* cube_t2 ;
+
+void trInit() {
+    triangle_1 = malloc(sizeof(pt_2d)*3);
+    triangle_2 = malloc(sizeof(pt_2d)*3);
+    cube_t1 = malloc(sizeof(pt_2d)*6);
+    cube_t2 = malloc(sizeof(pt_2d)*6);
+}
+
+double det2D(pt_2d* p1, pt_2d* p2, pt_2d* p3) {
+    return p1->x * (p2->y - p3->y)
+        + p2->x * (p3->y - p1->y)
+        + p3->x * (p1->y - p2->y);
+}
+
+void checkTriWinding(pt_2d * p1, pt_2d * p2, pt_2d * p3, bool allowReversed) {
+    double detTri = det2D(p1, p2, p3);
+    if (detTri < 0.0) {
+        if (allowReversed) {
+            double t = p3->x;
+            p3->x = p2->x;
+            p2->x = t;
+
+            t = p3->y;
+            p3->y = p2->y;
+            p2->y = t;
+        } else {
+            errno = 1;
+        }
+    }
+}
+
+bool boundaryCollideChk(pt_2d *p1, pt_2d *p2, pt_2d *p3, double eps) {
+    return det2D(p1, p2, p3) < eps;
+}
+
+bool boundaryDoesntCollideChk(pt_2d *p1, pt_2d *p2, pt_2d *p3, double eps) {
+    return det2D(p1, p2, p3) <= eps;
+}
+
+bool triTri2D(pt_2d* t1, pt_2d* t2, double eps, bool allowReversed, bool onBoundary) {
+    bool(*chkEdge)(pt_2d*, pt_2d*, pt_2d*, double);
+    int i;
+    errno = 0;
+
+    // Triangles must be expressed anti-clockwise
+    checkTriWinding(&t1[0], &t1[1], &t1[2], allowReversed);
+    if (errno != 0) {
+        return false;
+    }
+    checkTriWinding(&t2[0], &t2[1], &t2[2], allowReversed);
+    if (errno != 0) {
+        return false;
+    }
+
+    if (onBoundary) {
+        // pt_2ds on the boundary are considered as colliding
+        chkEdge = boundaryCollideChk;
+    } else {
+        // pt_2ds on the boundary are not considered as colliding
+        chkEdge = boundaryDoesntCollideChk;
+    }
+
+    //For edge E of trangle 1,
+    for (i = 0; i < 3; ++i) {
+        int j = (i + 1) % 3;
+
+        //Check all points of trangle 2 lay on the external side of the edge E. If
+        //they do, the triangles do not collide.
+        if (chkEdge(&t1[i], &t1[j], &t2[0], eps) &&
+            chkEdge(&t1[i], &t1[j], &t2[1], eps) &&
+            chkEdge(&t1[i], &t1[j], &t2[2], eps)) {
+            return false;
+        }
+    }
+
+    //For edge E of trangle 2,
+    for (i = 0; i < 3; i++) {
+        int j = (i + 1) % 3;
+
+        //Check all points of trangle 1 lay on the external side of the edge E. If
+        //they do, the triangles do not collide.
+        if (chkEdge(&t2[i], &t2[j], &t1[0], eps) &&
+            chkEdge(&t2[i], &t2[j], &t1[1], eps) &&
+            chkEdge(&t2[i], &t2[j], &t1[2], eps))
+            return false;
+    }
+
+    //The triangles collide
+    return true;
+}
+
+bool triangleIntersection(pt_2d* tri1, pt_2d* tri2) {
+    return triTri2D(tri1, tri2, 0.0, false, true);
+}
+
+bool triangleIntersectionDec(pt_2d t1_1, pt_2d t1_2, pt_2d t1_3, pt_2d t2_1, pt_2d t2_2, pt_2d t2_3) {
+    triangle_1[0] = t1_1;
+    triangle_1[1] = t1_2;
+    triangle_1[2] = t1_3;
+    triangle_2[0] = t2_1;
+    triangle_2[1] = t2_2;
+    triangle_2[2] = t2_3;
+    return triangleIntersection(triangle_1, triangle_2);
+}
+
+bool multipleTrianglesIntersection(pt_2d* tri1, int len1, pt_2d* tri2, int len2) {
+    for(int k1 = 0; k1 < len1; k1+=3) {
+        for(int k2 = 0; k2 < len2; k2+=3) {
+            if(triangleIntersection(&tri1[k1], &tri2[k2])) {
+                return true;
+            }
+        }
+    }
+    return false ;
+}
+
+pt_2d to_fpoint(double x0, double y0, double z0) {
+    pt_2d res;
+    res.x = x0;
+    res.y = y0;
+    res.z = z0;
+    return res;
+}
+
+int returnTriangle(
+    double x0, double y0, double z0,
+    double x1, double y1, double z1,
+    double x2, double y2, double z2,
+    pt_2d* retarr
+) {
+    project_to_camera(x0, y0, z0, &px0, &py0, &pz0);
+    project_to_camera(x1, y1, z1, &px1, &py1, &pz1);
+    project_to_camera(x2, y2, z2, &px2, &py2, &pz2);
+    if(pz0 >= draw_constant && pz1 >= draw_constant && pz2 >= draw_constant) {
+        retarr[0] = to_fpoint(1500.0 * (1.0 + (px0 / (1.5 * pz0 * tan_fov))) / 2.0, 1000.0 * (1.0 + (py0 / (pz0 * tan_fov))) / 2.0, pz0);
+        retarr[1] = to_fpoint(1500.0 * (1.0 + (px1 / (1.5 * pz1 * tan_fov))) / 2.0, 1000.0 * (1.0 + (py1 / (pz1 * tan_fov))) / 2.0, pz1);
+        retarr[2] = to_fpoint(1500.0 * (1.0 + (px2 / (1.5 * pz2 * tan_fov))) / 2.0, 1000.0 * (1.0 + (py2 / (pz2 * tan_fov))) / 2.0, pz2);
+        return 3;
+    } else if((pz0 >= draw_constant) + (pz1 >= draw_constant) + (pz2 >= draw_constant) == 2) {
+        if(pz0 < draw_constant) {     
+            // pz1 >= draw_constant and pz2 >+ draw_constant
+            fpx0 = px1 ; fpy0 = py1 ; fpz0 = pz1 ;
+            fpx1 = px2 ; fpy1 = py2 ; fpz1 = pz2 ;
+            // 1-0 segment
+            project_to_camera(
+                convex_pt(x1, x0, (pz1 - draw_constant)/(pz1 - pz0)), 
+                convex_pt(y1, y0, (pz1 - draw_constant)/(pz1 - pz0)), 
+                convex_pt(z1, z0, (pz1 - draw_constant)/(pz1 - pz0)), 
+            &mpx0, &mpy0, &mpz0) ;
+            
+            // 0-2 segment
+            project_to_camera(
+                convex_pt(x2, x0, (pz2 - draw_constant)/(pz2 - pz0)), 
+                convex_pt(y2, y0, (pz2 - draw_constant)/(pz2 - pz0)), 
+                convex_pt(z2, z0, (pz2 - draw_constant)/(pz2 - pz0)), 
+            &mpx1, &mpy1, &mpz1) ;
+        } else if(pz1 < draw_constant) {     
+            // pz0 >= draw_constant and pz2 >+ draw_constant
+            fpx0 = px0 ; fpy0 = py0 ; fpz0 = pz0 ;
+            fpx1 = px2 ; fpy1 = py2 ; fpz1 = pz2 ;
+            // 0-1 segment
+            project_to_camera(
+                convex_pt(x0, x1, (pz0 - draw_constant)/(pz0 - pz1)), 
+                convex_pt(y0, y1, (pz0 - draw_constant)/(pz0 - pz1)), 
+                convex_pt(z0, z1, (pz0 - draw_constant)/(pz0 - pz1)), 
+            &mpx0, &mpy0, &mpz0) ;
+            
+            // 1-2 segment
+            project_to_camera(
+                convex_pt(x2, x1, (pz2 - draw_constant)/(pz2 - pz1)), 
+                convex_pt(y2, y1, (pz2 - draw_constant)/(pz2 - pz1)), 
+                convex_pt(z2, z1, (pz2 - draw_constant)/(pz2 - pz1)), 
+            &mpx1, &mpy1, &mpz1) ;
+        } else /*if(pz2 < draw_constant)*/ {     
+            // pz1 >= draw_constant and pz0 >+ draw_constant
+            fpx0 = px0 ; fpy0 = py0 ; fpz0 = pz0 ;
+            fpx1 = px1 ; fpy1 = py1 ; fpz1 = pz1 ;
+            // 0-2 segment
+            project_to_camera(
+                convex_pt(x0, x2, (pz0 - draw_constant)/(pz0 - pz2)), 
+                convex_pt(y0, y2, (pz0 - draw_constant)/(pz0 - pz2)), 
+                convex_pt(z0, z2, (pz0 - draw_constant)/(pz0 - pz2)), 
+            &mpx0, &mpy0, &mpz0) ;
+            
+            // 1-2 segment
+            project_to_camera(
+                convex_pt(x1, x2, (pz1 - draw_constant)/(pz1 - pz2)), 
+                convex_pt(y1, y2, (pz1 - draw_constant)/(pz1 - pz2)), 
+                convex_pt(z1, z2, (pz1 - draw_constant)/(pz1 - pz2)), 
+            &mpx1, &mpy1, &mpz1) ;
+        }
+
+        retarr[0] = to_fpoint(1500.0 * (1.0 + (fpx0 / (1.5 * fpz0 * tan_fov))) / 2.0, 1000.0 * (1.0 + (fpy0 / (fpz0 * tan_fov))) / 2.0, fpz0);
+        retarr[1] = to_fpoint(1500.0 * (1.0 + (mpx0 / (1.5 * mpz0 * tan_fov))) / 2.0, 1000.0 * (1.0 + (mpy0 / (mpz0 * tan_fov))) / 2.0, mpz0);
+        retarr[2] = to_fpoint(1500.0 * (1.0 + (fpx1 / (1.5 * fpz1 * tan_fov))) / 2.0, 1000.0 * (1.0 + (fpy1 / (fpz1 * tan_fov))) / 2.0, fpz1);
+        retarr[3] = to_fpoint(1500.0 * (1.0 + (mpx0 / (1.5 * mpz0 * tan_fov))) / 2.0, 1000.0 * (1.0 + (mpy0 / (mpz0 * tan_fov))) / 2.0, mpz0);
+        retarr[4] = to_fpoint(1500.0 * (1.0 + (mpx1 / (1.5 * mpz1 * tan_fov))) / 2.0, 1000.0 * (1.0 + (mpy1 / (mpz1 * tan_fov))) / 2.0, mpz1);
+        retarr[5] = to_fpoint(1500.0 * (1.0 + (fpx1 / (1.5 * fpz1 * tan_fov))) / 2.0, 1000.0 * (1.0 + (fpy1 / (fpz1 * tan_fov))) / 2.0, fpz1);
+        return 6;
+    } else if((pz0 >= draw_constant) + (pz1 >= draw_constant) + (pz2 >= draw_constant) == 1) {
+        if(pz0 >= draw_constant) {
+            project_to_camera(
+                convex_pt(x0, x1, (pz0 - draw_constant)/(pz0 - pz1)),
+                convex_pt(y0, y1, (pz0 - draw_constant)/(pz0 - pz1)),
+                convex_pt(z0, z1, (pz0 - draw_constant)/(pz0 - pz1)),
+            &px1, &py1, &pz1);
+            project_to_camera(
+                convex_pt(x0, x2, (pz0 - draw_constant)/(pz0 - pz2)),
+                convex_pt(y0, y2, (pz0 - draw_constant)/(pz0 - pz2)),
+                convex_pt(z0, z2, (pz0 - draw_constant)/(pz0 - pz2)),
+            &px2, &py2, &pz2);
+        } else if(pz1 >= draw_constant) {
+            project_to_camera(
+                convex_pt(x1, x0, (pz1 - draw_constant)/(pz1 - pz0)),
+                convex_pt(y1, y0, (pz1 - draw_constant)/(pz1 - pz0)),
+                convex_pt(z1, z0, (pz1 - draw_constant)/(pz1 - pz0)),
+            &px0, &py0, &pz0);
+            project_to_camera(
+                convex_pt(x1, x2, (pz1 - draw_constant)/(pz1 - pz2)),
+                convex_pt(y1, y2, (pz1 - draw_constant)/(pz1 - pz2)),
+                convex_pt(z1, z2, (pz1 - draw_constant)/(pz1 - pz2)),
+            &px2, &py2, &pz2);
+        } else if(pz2 >= draw_constant) {
+            project_to_camera(
+                convex_pt(x2, x0, (pz2 - draw_constant)/(pz2 - pz0)),
+                convex_pt(y2, y0, (pz2 - draw_constant)/(pz2 - pz0)),
+                convex_pt(z2, z0, (pz2 - draw_constant)/(pz2 - pz0)),
+            &px0, &py0, &pz0);
+            project_to_camera(
+                convex_pt(x2, x1, (pz2 - draw_constant)/(pz2 - pz1)),
+                convex_pt(y2, y1, (pz2 - draw_constant)/(pz2 - pz1)),
+                convex_pt(z2, z1, (pz2 - draw_constant)/(pz2 - pz1)),
+            &px1, &py1, &pz1);
+        }
+
+        retarr[0] = to_fpoint(1500.0 * (1.0 + (px0 / (1.5 * pz0 * tan_fov))) / 2.0, 1000.0 * (1.0 + (py0 / (pz0 * tan_fov))) / 2.0, pz0);
+        retarr[1] = to_fpoint(1500.0 * (1.0 + (px1 / (1.5 * pz1 * tan_fov))) / 2.0, 1000.0 * (1.0 + (py1 / (pz1 * tan_fov))) / 2.0, pz1);
+        retarr[2] = to_fpoint(1500.0 * (1.0 + (px2 / (1.5 * pz2 * tan_fov))) / 2.0, 1000.0 * (1.0 + (py2 / (pz2 * tan_fov))) / 2.0, pz2);
+        return 3;
+    } else {
+        return 0;
+    }
+}
+
+int fillPolygon(int sf, cube_0 c, int trig, pt_2d* ret) {
+    // trig is either 0 or 1
+    // returns the length of the result
+    if(sf == 0 || sf == 1) {        // x
+        if(trig == 0) {
+            return returnTriangle( 
+                c.x + c.w*(sf==0), c.y,       c.z, 
+                c.x + c.w*(sf==0), c.y + c.h, c.z, 
+                c.x + c.w*(sf==0), c.y + c.h, c.z + c.d, 
+                ret
+            );
+        } else {
+            return returnTriangle( 
+                c.x + c.w*(sf==0), c.y,       c.z, 
+                c.x + c.w*(sf==0), c.y,       c.z + c.d, 
+                c.x + c.w*(sf==0), c.y + c.h, c.z + c.d, 
+                ret
+            );
+        }
+    } else if(sf == 2 || sf == 3) { // y
+        if(trig == 0) {
+            return returnTriangle(
+                c.x,       c.y + c.h*(sf==2), c.z, 
+                c.x + c.w, c.y + c.h*(sf==2), c.z, 
+                c.x + c.w, c.y + c.h*(sf==2), c.z + c.d, 
+                ret
+            );
+        } else {
+            return returnTriangle(
+                c.x,       c.y + c.h*(sf==2), c.z, 
+                c.x,       c.y + c.h*(sf==2), c.z + c.d, 
+                c.x + c.w, c.y + c.h*(sf==2), c.z + c.d, 
+                ret
+            );
+        }
+    } else {                        // z
+        if(trig == 0) {
+            return returnTriangle(
+                c.x,       c.y,       c.z + c.d*(sf==4), 
+                c.x + c.w, c.y,       c.z + c.d*(sf==4), 
+                c.x + c.w, c.y + c.h, c.z + c.d*(sf==4), 
+                ret
+            );
+        } else {
+            return returnTriangle(
+                c.x,       c.y,       c.z + c.d*(sf==4), 
+                c.x,       c.y + c.h, c.z + c.d*(sf==4), 
+                c.x + c.w, c.y + c.h, c.z + c.d*(sf==4), 
+                ret
+            );
+        }
+    }
+}
+
+bool cubeOverlap(cube_0 c1, cube_0 c2) {
+    int len1 = 0;
+    int len2 = 0;
+    for(int i1 = 0; i1 < 6; i1++) {
+        for(int i2 = i1+1; i2 < 6; i2++) {
+            for(int n = 0; n < 4; n++) {
+                len1 = fillPolygon(i1, c1, n%2, cube_t1);
+                len2 = fillPolygon(i2, c2, n/2, cube_t2);
+                if(multipleTrianglesIntersection(cube_t1, len1, cube_t2, len2)) {
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
\ No newline at end of file
diff --git a/src/triangles.h b/src/triangles.h
new file mode 100644
index 0000000..ebb7092
--- /dev/null
+++ b/src/triangles.h
@@ -0,0 +1,20 @@
+#ifndef TRIANGLES_H
+#define TRIANGLES_H
+
+void trInit();
+
+double det2D(pt_2d * p1, pt_2d * p2, pt_2d * p3) ;
+void checkTriWinding(pt_2d * p1, pt_2d * p2, pt_2d * p3, bool allowReversed) ;
+bool boundaryCollideChk(pt_2d *p1, pt_2d *p2, pt_2d *p3, double eps) ;
+bool boundaryDoesntCollideChk(pt_2d *p1, pt_2d *p2, pt_2d *p3, double eps) ;
+
+bool triTri2D(pt_2d* t1, pt_2d* t2, double eps, bool allowReversed, bool onBoundary) ;
+bool triangleIntersection(pt_2d* tri1, pt_2d* tri2);
+bool triangleIntersectionDec(pt_2d t1_1, pt_2d t1_2, pt_2d t1_3, pt_2d t2_1, pt_2d t2_2, pt_2d t2_3);
+
+int returnTriangle(double x0, double y0, double z0, double x1, double y1, double z1, double x2, double y2, double z2, pt_2d* retarr);
+int fillPolygon(int sf, cube_0 c, int trig, pt_2d* ret);
+
+bool cubeOverlap(cube_0 c1, cube_0 c2);
+
+#endif
\ No newline at end of file