tr2/objects/pickup: add 3d mesh drawing

Resolves #1634.

docs/tr2/CHANGELOG.md

@@ -7,6 +7,7 @@
 - added the ability to skip FMVs with the action key (#1650)
 - added the ability to hold forward/back to move through menus more quickly (#1644)
 - added optional rendering of pickups in the UI as 3D meshes (#1633)
+- added optional rendering of pickups on the ground as 3D meshes (#1634)
 - changed the inputs backend from DirectX to SDL (#1695)
     - improved controller support to match TR1X
     - changed the number of custom layouts to 3

src/tr2/game/objects/common.c

@@ -2,9 +2,12 @@
 
 #include "game/items.h"
 #include "game/lara/misc.h"
+#include "game/matrix.h"
 #include "global/funcs.h"
 #include "global/vars.h"
 
+#include <libtrx/utils.h>
+
 OBJECT *Object_GetObject(GAME_OBJECT_ID object_id)
 {
     return &g_Objects[object_id];
@@ -45,3 +48,83 @@ void __cdecl Object_Collision_Trap(
         Object_Collision(item_num, lara_item, coll);
     }
 }
+
+BOUNDS_16 Object_GetBoundingBox(
+    const OBJECT *const obj, const FRAME_INFO *const frame)
+{
+    int16_t **mesh_ptrs = &g_Meshes[obj->mesh_idx];
+    int32_t *bone = &g_AnimBones[obj->bone_idx];
+    const int16_t *mesh_rots = frame->mesh_rots;
+
+    Matrix_PushUnit();
+    Matrix_TranslateRel(frame->offset.x, frame->offset.y, frame->offset.z);
+    Matrix_RotYXZsuperpack(&mesh_rots, 0);
+
+    BOUNDS_16 new_bounds = {
+        .min_x = 0x7FFF,
+        .min_y = 0x7FFF,
+        .min_z = 0x7FFF,
+        .max_x = -0x7FFF,
+        .max_y = -0x7FFF,
+        .max_z = -0x7FFF,
+    };
+
+    for (int32_t mesh_idx = 0; mesh_idx < obj->mesh_count; mesh_idx++) {
+        if (mesh_idx != 0) {
+            int32_t bone_extra_flags = *bone;
+            if (bone_extra_flags & BF_MATRIX_POP) {
+                Matrix_Pop();
+            }
+
+            if (bone_extra_flags & BF_MATRIX_PUSH) {
+                Matrix_Push();
+            }
+
+            Matrix_TranslateRel(bone[1], bone[2], bone[3]);
+            Matrix_RotYXZsuperpack(&mesh_rots, 0);
+            bone += 4;
+        }
+
+        const int16_t *obj_ptr = mesh_ptrs[mesh_idx];
+        obj_ptr += 5;
+        const int32_t vtx_count = *obj_ptr++;
+        for (int32_t i = 0; i < vtx_count; i++) {
+            // clang-format off
+            const MATRIX *const mptr = g_MatrixPtr;
+            const double xv = (
+                mptr->_00 * obj_ptr[0] +
+                mptr->_01 * obj_ptr[1] +
+                mptr->_02 * obj_ptr[2] +
+                mptr->_03
+            );
+            const double yv = (
+                mptr->_10 * obj_ptr[0] +
+                mptr->_11 * obj_ptr[1] +
+                mptr->_12 * obj_ptr[2] +
+                mptr->_13
+            );
+            double zv = (
+                mptr->_20 * obj_ptr[0] +
+                mptr->_21 * obj_ptr[1] +
+                mptr->_22 * obj_ptr[2] +
+                mptr->_23
+            );
+            // clang-format on
+
+            const int32_t x = ((int32_t)xv) >> W2V_SHIFT;
+            const int32_t y = ((int32_t)yv) >> W2V_SHIFT;
+            const int32_t z = ((int32_t)zv) >> W2V_SHIFT;
+
+            new_bounds.min_x = MIN(new_bounds.min_x, x);
+            new_bounds.min_y = MIN(new_bounds.min_y, y);
+            new_bounds.min_z = MIN(new_bounds.min_z, z);
+            new_bounds.max_x = MAX(new_bounds.max_x, x);
+            new_bounds.max_y = MAX(new_bounds.max_y, y);
+            new_bounds.max_z = MAX(new_bounds.max_z, z);
+            obj_ptr += 3;
+        }
+    }
+
+    Matrix_Pop();
+    return new_bounds;
+}

src/tr2/game/objects/common.h

@@ -11,3 +11,5 @@ void __cdecl Object_Collision(
 
 void __cdecl Object_Collision_Trap(
     int16_t item_num, ITEM *lara_item, COLL_INFO *coll);
+
+BOUNDS_16 Object_GetBoundingBox(const OBJECT *obj, const FRAME_INFO *frame);

src/tr2/game/objects/general/pickup.c

@@ -1,13 +1,19 @@
 #include "game/objects/general/pickup.h"
 
+#include "config.h"
 #include "game/gameflow.h"
 #include "game/gun/gun.h"
 #include "game/input.h"
 #include "game/inventory/backpack.h"
+#include "game/inventory/common.h"
 #include "game/items.h"
 #include "game/lara/control.h"
 #include "game/lara/misc.h"
+#include "game/matrix.h"
+#include "game/objects/common.h"
+#include "game/output.h"
 #include "game/overlay.h"
+#include "game/room.h"
 #include "global/funcs.h"
 #include "global/vars.h"
 
@@ -179,11 +185,107 @@ void Pickup_Setup(OBJECT *const obj)
     // TODO: change this to Pickup_Collision after we decompile
     // both comparisons in ExtractSaveGameInfo() and GetCarriedItems()
     obj->collision = (void *)0x00437E70;
-    obj->draw_routine = Object_DrawSpriteItem;
+    obj->draw_routine = Pickup_Draw;
     obj->save_position = 1;
     obj->save_flags = 1;
 }
 
+void Pickup_Draw(const ITEM *const item)
+{
+    if (!g_Config.visuals.enable_3d_pickups) {
+        Object_DrawSpriteItem(item);
+        return;
+    }
+
+    if (!g_Objects[item->object_id].loaded) {
+        Object_DrawSpriteItem(item);
+        return;
+    }
+
+    // Convert item to menu display item.
+    const GAME_OBJECT_ID inv_object_id = Inv_GetItemOption(item->object_id);
+    const OBJECT *const obj = Object_GetObject(inv_object_id);
+    if (!obj->loaded || obj->mesh_count < 0) {
+        Object_DrawSpriteItem(item);
+        return;
+    }
+
+    // Get the first frame of the first animation, and its bounding box.
+    const FRAME_INFO *frame = (const FRAME_INFO *)obj->frame_base;
+    const BOUNDS_16 bounds = Object_GetBoundingBox(obj, frame);
+
+    // First - Is there floor under the item?
+    // This is mostly true, but for example the 4 items in the Obelisk of
+    // Khamoon the 4 items are sitting on top of a static mesh which is not
+    // floor.
+    int16_t room_num = item->room_num;
+    const SECTOR *const sector =
+        Room_GetSector(item->pos.x, item->pos.y, item->pos.z, &room_num);
+    const int16_t floor_height =
+        Room_GetHeight(sector, item->pos.x, item->pos.y, item->pos.z);
+
+    int16_t offset;
+    if (item->pos.y == floor_height) {
+        // Is the floor "just below" the item? Take the position from the anim.
+        offset =
+            floor_height - frame->offset.y - (bounds.max_y - bounds.min_y) / 2;
+    } else {
+        // Otherwise leave it as-is.
+        offset = item->pos.y;
+    }
+
+    Matrix_Push();
+    Matrix_TranslateAbs(item->pos.x, offset, item->pos.z);
+    Matrix_RotYXZ(item->rot.y, item->rot.x, item->rot.z);
+
+    S_CalculateLight(item->pos.x, item->pos.y, item->pos.z, item->room_num);
+
+    const int32_t clip = S_GetObjectBounds(&frame->bounds);
+    if (clip) {
+        // From this point on the function is a slightly customised version
+        // of the code in DrawAnimatingItem starting with the line that
+        // matches the following line.
+        int32_t bit = 1;
+        int16_t **meshpp = &g_Meshes[obj->mesh_idx];
+        int32_t *bone = &g_AnimBones[obj->bone_idx];
+
+        Matrix_TranslateRel(frame->offset.x, frame->offset.y, frame->offset.z);
+
+        const int16_t *mesh_rots = frame->mesh_rots;
+        Matrix_RotYXZsuperpack(&mesh_rots, 0);
+
+        if (item->mesh_bits & bit) {
+            Output_InsertPolygons(*meshpp++, clip);
+        }
+
+        for (int i = 1; i < obj->mesh_count; i++) {
+            int32_t bone_extra_flags = *bone;
+            if (bone_extra_flags & BF_MATRIX_POP) {
+                Matrix_Pop();
+            }
+
+            if (bone_extra_flags & BF_MATRIX_PUSH) {
+                Matrix_Push();
+            }
+
+            Matrix_TranslateRel(bone[1], bone[2], bone[3]);
+            Matrix_RotYXZsuperpack(&mesh_rots, 0);
+
+            // Extra rotation is ignored in this case as it's not needed.
+
+            bit <<= 1;
+            if (item->mesh_bits & bit) {
+                Output_InsertPolygons(*meshpp, clip);
+            }
+
+            bone += 4;
+            meshpp++;
+        }
+    }
+
+    Matrix_Pop();
+}
+
 void __cdecl Pickup_Collision(
     const int16_t item_num, ITEM *const lara_item, COLL_INFO *const coll)
 {

src/tr2/game/objects/general/pickup.h

@@ -4,6 +4,8 @@
 
 void Pickup_Setup(OBJECT *obj);
 
+void Pickup_Draw(const ITEM *item);
+
 void __cdecl Pickup_Collision(
     int16_t item_num, ITEM *lara_item, COLL_INFO *coll);
 

src/tr2/game/overlay.c

@@ -6,6 +6,7 @@
 #include "game/inventory/common.h"
 #include "game/matrix.h"
 #include "game/music.h"
+#include "game/objects/common.h"
 #include "game/output.h"
 #include "game/text.h"
 #include "game/viewport.h"
@@ -71,88 +72,6 @@ static float M_Ease(const int32_t cur_frame, const int32_t max_frames)
     return result;
 }
 
-static BOUNDS_16 M_GetBounds(
-    const OBJECT *const obj, const FRAME_INFO *const frame)
-{
-    int16_t **mesh_ptrs = &g_Meshes[obj->mesh_idx];
-    int32_t *bone = &g_AnimBones[obj->bone_idx];
-    const int16_t *mesh_rots = frame->mesh_rots;
-
-    Matrix_PushUnit();
-    Matrix_TranslateRel(frame->offset.x, frame->offset.y, frame->offset.z);
-    Matrix_RotYXZsuperpack(&mesh_rots, 0);
-
-    BOUNDS_16 new_bounds = {
-        .min_x = 0x7FFF,
-        .min_y = 0x7FFF,
-        .min_z = 0x7FFF,
-        .max_x = -0x7FFF,
-        .max_y = -0x7FFF,
-        .max_z = -0x7FFF,
-    };
-
-    for (int32_t mesh_idx = 0; mesh_idx < obj->mesh_count; mesh_idx++) {
-        if (mesh_idx != 0) {
-            int32_t bone_extra_flags = *bone;
-            if (bone_extra_flags & BF_MATRIX_POP) {
-                Matrix_Pop();
-            }
-
-            if (bone_extra_flags & BF_MATRIX_PUSH) {
-                Matrix_Push();
-            }
-
-            Matrix_TranslateRel(bone[1], bone[2], bone[3]);
-            Matrix_RotYXZsuperpack(&mesh_rots, 0);
-            bone += 4;
-        }
-
-        const int16_t *obj_ptr = mesh_ptrs[mesh_idx];
-        obj_ptr += 5;
-        const int32_t vtx_count = *obj_ptr++;
-        for (int32_t i = 0; i < vtx_count; i++) {
-            PHD_VBUF *const vbuf = &g_PhdVBuf[i];
-
-            // clang-format off
-            const MATRIX *const mptr = g_MatrixPtr;
-            const double xv = (
-                mptr->_00 * obj_ptr[0] +
-                mptr->_01 * obj_ptr[1] +
-                mptr->_02 * obj_ptr[2] +
-                mptr->_03
-            );
-            const double yv = (
-                mptr->_10 * obj_ptr[0] +
-                mptr->_11 * obj_ptr[1] +
-                mptr->_12 * obj_ptr[2] +
-                mptr->_13
-            );
-            double zv = (
-                mptr->_20 * obj_ptr[0] +
-                mptr->_21 * obj_ptr[1] +
-                mptr->_22 * obj_ptr[2] +
-                mptr->_23
-            );
-            // clang-format on
-
-            const int32_t x = ((int32_t)xv) >> W2V_SHIFT;
-            const int32_t y = ((int32_t)yv) >> W2V_SHIFT;
-            const int32_t z = ((int32_t)zv) >> W2V_SHIFT;
-
-            new_bounds.min_x = MIN(new_bounds.min_x, x);
-            new_bounds.min_y = MIN(new_bounds.min_y, y);
-            new_bounds.min_z = MIN(new_bounds.min_z, z);
-            new_bounds.max_x = MAX(new_bounds.max_x, x);
-            new_bounds.max_y = MAX(new_bounds.max_y, y);
-            new_bounds.max_z = MAX(new_bounds.max_z, z);
-            obj_ptr += 3;
-        }
-    }
-
-    Matrix_Pop();
-    return new_bounds;
-}
-
 bool __cdecl Overlay_FlashCounter(const int32_t ticks)
 {
     if (m_FlashCounter > 0) {
@@ -457,7 +376,7 @@ static void M_DrawPickup3D(const DISPLAY_PICKUP *const pickup)
     if (frame->bounds.min_x == frame->bounds.max_x
         && frame->bounds.min_y == frame->bounds.max_y) {
         // fix broken collision box for the prayer wheel
-        bounds = M_GetBounds(obj, frame);
+        bounds = Object_GetBoundingBox(obj, frame);
     }
 
     const int32_t scale = 1280;