From 30d425aa26a3aa802cb2ff55f1f7655be056f3ed Mon Sep 17 00:00:00 2001
From: jussi
Date: Thu, 31 Mar 2022 13:55:02 +0300
Subject: Screen-space related functions for 3DCamera.

---
 src/core.c     | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lua_core.c | 26 ++++++++++++++++++
 2 files changed, 109 insertions(+)

(limited to 'src')

diff --git a/src/core.c b/src/core.c
index 8f67c34..74e6607 100644
--- a/src/core.c
+++ b/src/core.c
@@ -2337,3 +2337,86 @@ int lcoreUpdateCamera3D( lua_State *L ) {
 
 	return 1;
 }
+
+/*
+## Core - Screen-space
+*/
+
+/*
+> ray = RL_GetMouseRay( Vector2 mousePosition, Camera3D camera )
+
+Get a ray trace from mouse position
+
+- Failure return false
+- Success return Ray
+*/
+int lcoreGetMouseRay( lua_State *L ) {
+	if ( !lua_istable( L, -2 ) || !lua_isnumber( L, -1 ) ) {
+		TraceLog( LOG_WARNING, "%s", "Bad call of function. RL_GetMouseRay( Vector2 mousePosition, Camera3D camera )" );
+		lua_pushboolean( L, false );
+		return 1;
+	}
+	size_t cameraId = lua_tointeger( L, -1 );
+	lua_pop( L, 1 );
+	Vector2 mousePosition = uluaGetVector2( L );
+
+	if ( !validCamera3D( cameraId ) ) {
+		lua_pushboolean( L, false );
+		return 1;
+	}
+	uluaPushRay( L, GetMouseRay( mousePosition, *state->camera3Ds[ cameraId ] ) );
+
+	return 1;
+}
+
+/*
+> matrix = RL_GetCameraMatrix( Camera3D camera )
+
+Get camera transform matrix ( view matrix )
+
+- Failure return false
+- Success return Matrix
+*/
+int lcoreGetCameraMatrix( lua_State *L ) {
+	if ( !lua_isnumber( L, -1 ) ) {
+		TraceLog( LOG_WARNING, "%s", "Bad call of function. RL_GetCameraMatrix( Camera3D camera )" );
+		lua_pushboolean( L, false );
+		return 1;
+	}
+	size_t cameraId = lua_tointeger( L, -1 );
+
+	if ( !validCamera3D( cameraId ) ) {
+		lua_pushboolean( L, false );
+		return 1;
+	}
+	uluaPushMatrix( L, GetCameraMatrix( *state->camera3Ds[ cameraId ] ) );
+
+	return 1;
+}
+
+/*
+> position = RL_GetWorldToScreen( Vector3 position, Camera3D camera )
+
+Get the screen space position for a 3d world space position
+
+- Failure return false
+- Success return Vector2
+*/
+int lcoreGetWorldToScreen( lua_State *L ) {
+	if ( !lua_istable( L, -2 ) || !lua_isnumber( L, -1 ) ) {
+		TraceLog( LOG_WARNING, "%s", "Bad call of function. RL_GetWorldToScreen( Vector3 position, Camera3D camera )" );
+		lua_pushboolean( L, false );
+		return 1;
+	}
+	size_t cameraId = lua_tointeger( L, -1 );
+	lua_pop( L, 1 );
+	Vector3 position = uluaGetVector3( L );
+
+	if ( !validCamera3D( cameraId ) ) {
+		lua_pushboolean( L, false );
+		return 1;
+	}
+	uluaPushVector2( L, GetWorldToScreen( position, *state->camera3Ds[ cameraId ] ) );
+
+	return 1;
+}
diff --git a/src/lua_core.c b/src/lua_core.c
index 4cfbafd..6006474 100644
--- a/src/lua_core.c
+++ b/src/lua_core.c
@@ -597,6 +597,10 @@ void luaRegister() {
 	lua_register( L, "RL_GetGestureDragAngle", lcoreGetGestureDragAngle );
 	lua_register( L, "RL_GetGesturePinchVector", lcoreGetGesturePinchVector );
 	lua_register( L, "RL_GetGesturePinchAngle", lcoreGetGesturePinchAngle );
+		/* Screen-space. */
+	lua_register( L, "RL_GetMouseRay", lcoreGetMouseRay );
+	lua_register( L, "RL_GetCameraMatrix", lcoreGetCameraMatrix );
+	lua_register( L, "RL_GetWorldToScreen", lcoreGetWorldToScreen );
 
 	/* Shapes. */
 		/* Drawing. */
@@ -1304,6 +1308,28 @@ void uluaPushMatrix( lua_State *L, Matrix matrix ) {
 	lua_rawseti( L, -2, 4 );
 }
 
+void uluaPushRay( lua_State *L, Ray ray ) {
+	lua_createtable( L, 2, 0 );
+
+	lua_createtable( L, 3, 0 );
+	lua_pushnumber( L, ray.position.x );
+	lua_rawseti( L, -2, 1 );
+	lua_pushnumber( L, ray.position.y );
+	lua_rawseti( L, -2, 2 );
+	lua_pushnumber( L, ray.position.z );
+	lua_rawseti( L, -2, 3 );
+	lua_rawseti( L, -2, 1 );
+
+	lua_createtable( L, 3, 0 );
+	lua_pushnumber( L, ray.direction.x );
+	lua_rawseti( L, -2, 1 );
+	lua_pushnumber( L, ray.direction.y );
+	lua_rawseti( L, -2, 2 );
+	lua_pushnumber( L, ray.direction.z );
+	lua_rawseti( L, -2, 3 );
+	lua_rawseti( L, -2, 2 );
+}
+
 void uluaPushRayCollision( lua_State *L, RayCollision rayCol ) {
 	lua_createtable( L, 4, 0 );
 	lua_pushboolean( L, rayCol.hit );
-- 
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