Collision - Revision history

Mzxrules at 16:03, 6 August 2021

2021-08-06T16:03:30Z

Mzxrules: /* Simple Body Collision */

2020-10-20T05:44:00Z

‎Simple Body Collision

Mzxrules: /* CollisionBody struct (Instance) */

2020-10-19T13:06:10Z

‎CollisionBody struct (Instance)

Mzxrules: /* Simple Body Collision */

2019-07-20T22:49:57Z

‎Simple Body Collision

Nokaubure: /* Cylinder Body Collision Struct (Actor Instance) */

2019-06-30T00:51:11Z

‎Cylinder Body Collision Struct (Actor Instance)

Nokaubure: filled the table more

2019-06-30T00:33:02Z

filled the table more

Mzxrules: /* Simple Body Collision */

2019-06-29T23:37:24Z

‎Simple Body Collision

Mzxrules: /* Simple Body Collision */

2019-03-02T05:32:34Z

‎Simple Body Collision

Mzxrules: /* Simple Body Collision */

2019-02-20T08:14:23Z

‎Simple Body Collision

Mzxrules: /* Poly-based Collision */

2018-08-08T00:30:51Z

‎Poly-based Collision

@@ Line 5: / Line 5: @@
 === Poly Lookup Table ===
-[[Global Context]] + 0x7C0 is the address of the struct managing background collision information.
+[[Game Play]] + 0x7C0 is the address of the struct managing background collision information.
 = ptr to scene collision mesh
@@ Line 32: / Line 32: @@
 Actors can have mesh-based collisions as well. The game engine can handle up to a maximum of 50 meshes, plus the scene file's mesh (which is assigned index 50 or 0x32).
-Global Context + 0x7C0 + 0x54 is the start address of the first actor mesh record. Each record is 0x64 bytes, as seen below.
+Game Play + 0x7C0 + 0x54 is the start address of the first actor mesh record. Each record is 0x64 bytes, as seen below.
-Global Context + 0x1B9C is an array of halfwords storing whether an actor mesh is loaded or not.
+Game Play + 0x1B9C is an array of halfwords storing whether an actor mesh is loaded or not.
 {|class="wikitable"
@@ Line 258: / Line 258: @@
 CollisionBody elements subscribed to group AT will be collided into group AC. I believe group OT will be collided amongst themselves.
-=== [[Global Context (Game)|Global Context]] ===
+=== [[Game Play]] ===
 <pre>

@@ Line 251: / Line 251: @@
 | AT || Attack
 |-
-| AC || Attack Checker
+| AC || Attack Collider
 |-
-| OT || Object Toucher?
+| OC || Object Collider
 |}

@@ Line 276: / Line 276: @@
 <pre>
-/* 0x00 */ actor_t*    //Actor Instance
+typedef struct {
-/* 0x04 */ actor_t*    //Colliding Actor Instance Type 1?
+    /* 0x00 */ struct Actor* actor;
-/* 0x08 */ actor_t*    //Colliding Actor Instance Type 2?
+    /* 0x04 */ struct Actor* at;
-/* 0x0C */ actor_t*    //Colliding Actor Instance Type 3?
+    /* 0x08 */ struct Actor* ac;
-/* 0x10 */ u8          //CSO 0x01 Collides Flags (opposite 0x11)
+    /* 0x0C */ struct Actor* oc;
-                            //if not & 0x0001, skip attack detection
+    /* 0x10 */ u8 atFlags; // Compared to acFlags
-                            // & 0x0040 == ?
+                           // if not & 0x0001, skip attack detection
-/* 0x11 */ u8          //CSO 0x02 Collision Check Flags (opposite 0x10)
+                           // & 0x0040 == ?
-                            //if not & 0x0001, skip collision with attack.
+    /* 0x11 */ u8 acFlags; // Compared to atFlags
-                            //if & 0x0002, is detecting a Deku Nut hit?
+                           // if not & 0x0001, skip collision with attack.
-/* 0x12 */ byte        //CSO 0x03, bitwise-and compared to opposing collision's 0x13 byte
+                           // if & 0x0002, is detecting a Deku Nut hit?
-/* 0x13 */ byte        //CSO 0x04, bitwise-and compared to opposing collision's 0x12 byte
+    /* 0x12 */ u8 maskA;   // Bitwise-and compared to maskB
-/* 0x14 */ byte        //CSO 0x00
+    /* 0x13 */ u8 maskB;   // Bitwise-and compared to maskA
-/* 0x15 */ u8          //CSO 0x05, Type
+    /* 0x14 */ u8 type;
-                         //00 = Cylinder Collection
+    /* 0x15 */ u8 shape;
                          //01 = Cylinder
-                         //02 = ? (potentially sphere, per debug rom console output)
+                         //02 = Tris Collection
-                         //03 = Triangles (2)
+                         //03 = Quad
-−
                          //references function pointer, start location at 800EFAB8
                          //used to reference function pointer, start location at 800EFB4C.
                          //Basically, on left compare to right,
                          //left's value * 0x10 + right's value * 0x04 = pointer look up
-//If Type == 0 (Cylinder Collection) or Type == 2 (Triangle Collection), the following variables exist:
+//If Type == 0 (Sphere Collection) or Type == 2 (Triangle Collection), the following variables exist:
 /* 0x18 */ int     //Number of Cylinders or Triangles
 /* 0x1C */ ptr     //Collection Array Start

@@ Line 241: / Line 241: @@
 * A collection of cylinders (Type 0)
 * A single cylinder (Type 1)
-* A collection of quads (Type 2)
+* A collection of triangles (Type 2)
 * A single quad (Type 3)

@@ Line 379: / Line 379: @@
 x40	short	//CSO 0x20 Cylinder radius or diameter
 x42	short	//CS0 0x22 Cylinder Height
-x44	short	//CSO 0x24
+x44	short	//CSO 0x24 y_shift
 x46	short	//Cylinder X
 x48	short	//Cylinder Y

@@ Line 360: / Line 360: @@
 x00	ptr 	//Actor Instance
 x08	ptr		//Colliding Actor Instance?
-x10	byte	//CSO 0x01
+x10	byte	//CSO 0x01  collider_flags
-x11	byte	//CSO 0x02 //if & 0x0002, is detecting a Deku Nut hit?
+x11	byte	//CSO 0x02  collide_flags //if & 0x0002, is detecting a Deku Nut hit?
-x12	byte	//CSO 0x03, bitwise-and compared to opposing collision's 0x13 byte
+x12	byte	//CSO 0x03, mask_a bitwise-and compared to opposing collision's 0x13 byte
-x13	byte	//CSO 0x04, bitwise-and compared to opposing collision's 0x12 byte
+x13	byte	//CSO 0x04, mask_b bitwise-and compared to opposing collision's 0x12 byte
 x14	byte	//CSO 0x00
 x15	byte	//CSO 0x05, used to reference function pointer, start location at 800EFB4C.
 				//Basically, on left compare to right, left's value * 0x10 + right's value * 0x04 = pointer look up
 x18	int 	//CSO 0x0C
-x1C	byte	//CSO 0x10
+x1C	byte	//CSO 0x10  Damage effect (normal, burn, freeze, shock, knockback)
 x1D	byte	//CSO 0x11, Damage Dealt when touched
-x20	int 	//CSO 0x14 (FFCF FFFF)
+x20	int 	//CSO 0x14  Collision exclusion mask (FFCF FFFF)
 x24	byte	//CSO 0x18
 x25	byte	//CSO 0x19
-x2C	byte	//CSO 0x08
+x2C	byte	//CSO 0x08 Flags
-x2D	byte	//CSO 0x1C
+x2D	byte	//CSO 0x1C toucher_flags
-x2E	byte	//CSO 0x1D
+x2E	byte	//CSO 0x1D bumper_flags
-x2F	byte	//CSO 0x1E
+x2F	byte	//CSO 0x1E flags_2
 x40	short	//CSO 0x20 Cylinder radius or diameter
 x42	short	//CS0 0x22 Cylinder Height

@@ Line 387: / Line 387: @@
 === Older Notes ===
 {{for|some old notes|Notes/Collision}}
 [[Category:Actors]]

@@ Line 236: / Line 236: @@
 == Simple Body Collision ==
-The simple body collision engine detects collision between two basic geometric shapes: cylinders and quadrilaterals. Cylinders are used most often, typically to represent the body of something, like an NPC or sign. Quadrilaterals are typically used for sword attacks and hit detection for bombable walls. Link's shield uses a quad.
+The simple body collision engine detects collision between three basic geometric shapes: cylinders, triangles, and quadrilaterals. Cylinders are used most often, typically to represent the body of something, like an NPC or sign. Quadrilaterals are typically used for sword attacks, Link's shield, and hit detection for bombable walls. Triangle collections are used for collision detection with the web in the center of the first room of the Deku Tree.
 A CollisionBody represents one of the following things:
@@ Line 244: / Line 244: @@
 * A single quad (Type 3)
-In order to perform collision testing, an entity will "subscribe" a CollisionBody to one of three collision "category" on every frame (game update). After all actors have been processed, collision checks will processed. The results of these collision checks will become available on the next update frame.
+In order to perform collision testing, an entity will "subscribe" a CollisionBody to one of three collision "category" on every frame (game update). After all actors have been processed, collision checks will processed. The results of these collision checks will become available to the actor on the next update frame.
 {|class="wikitable"
@@ Line 300: / Line 300: @@
                          //left's value * 0x10 + right's value * 0x04 = pointer look up
-//If Type == 0 (Cylinder Collection) or Type == 2 (Quad Collection), the following variables exist:
+//If Type == 0 (Cylinder Collection) or Type == 2 (Triangle Collection), the following variables exist:
-/* 0x18 */ int     //Number of Cylinders or Quads
+/* 0x18 */ int     //Number of Cylinders or Triangles
 /* 0x1C */ ptr     //Collection Array Start
 </pre>
 === CollisionBodyInfo ===
-Every cylinder and quad contains a CollisionBodyInfo struct. This struct seems to store the collision properties for that shape.
+Every cylinder, quad, and triangle contains a CollisionBodyInfo struct. This struct seems to store the collision properties for that shape.
 <pre>

@@ Line 236: / Line 236: @@
 == Simple Body Collision ==
-Some collision testing is handled by using very simplistic geometrical shapes. Cylinders are used most often, typically to represent the body of something. Triangles are typically used for attacks. Link's shield uses a quad.
+The simple body collision engine detects collision between two basic geometric shapes: cylinders and quadrilaterals. Cylinders are used most often, typically to represent the body of something, like an NPC or sign. Quadrilaterals are typically used for sword attacks and hit detection for bombable walls. Link's shield uses a quad.
-In order to perform collision testing, an entity will "subscribe" a simple body to one of three collision "category" on every frame (game update). After all actors have been processed, collision checks will processed.
 {|class="wikitable"
@@ Line 246: / Line 253: @@
 | AC || Attack Checker
 |-
-| OT || ?
+| OT || Object Toucher?
 |}
-Group AT will be collided into group AC. I believe group OT will be collided amongst themselves.
+CollisionBody elements subscribed to group AT will be collided into group AC. I believe group OT will be collided amongst themselves.
 === [[Global Context (Game)|Global Context]] ===
@@ Line 263: / Line 270: @@
 //1DA4C0, start of collision array OT (contains the most actors in Deku Tree)
 x12020
 </pre>
@@ Line 292: / Line 352: @@
 === Cylinder Body Collision Struct (Actor Instance) ===
 This is the in-memory struct used for actor collision related stuff. In NTSC 1.0 at least, this struct is 0x4C bytes long
 <pre>

@@ Line 2: / Line 2: @@
 == Poly-based Collision ==
-Follows the [[Collision Mesh Format|Collision Mesh format]]. Most meshes are stored in object files, rather than actor files like above.
+Polygon based collision detection is managed primarily by '''z_bgcheck.c'''. Follows the [[Collision Mesh Format|Collision Mesh format]]. Most meshes are stored in object files, rather than actor files like above.
 === Poly Lookup Table ===