Fix objs that don't have low LOD

Documentation/RACERS/MDL.md

@@ -19,25 +19,25 @@ The geometry section contains the coordinates, colors, drawing format (tri or qu
 | 0x0        | 0x1u     | Red                 | Vertex color intensity (R, G, B). Used as shading, since the model is textured. |
 | 0x1        | 0x1u     | Green               | Vertex color intensity (R, G, B). Used as shading, since the model is textured. |
 | 0x2        | 0x1u     | Blue                | Vertex color intensity (R, G, B). Used as shading, since the model is textured. |
-| 0x3        | 0x1u     | Color command (cmd) | This byte is ignored if you aren't reading the first vertex of a face. If cmd equals 0, then a new mesh starts. If cmd equals 0x38, then the next 3 vertexes will form a quad with the current vertex; if cmd does not equal 0x38, then the next 2 vertexes will make a triangle with the current vertex.                                                                   |
+| 0x3        | 0x1u     | Color command (cmd) | This byte is ignored if you aren't reading the first vertex of a face. If cmd equals 0, then a new mesh starts. If a new mesh starts and the red color equals 2, then the object has a low LOD mesh. If cmd equals 0x38, then the next 3 vertexes will form a quad with the current vertex; if cmd does not equal 0x38, then the next 2 vertexes will make a triangle with the current vertex.                                                                   |
 | 0x4        | 0x2s     | X                   | Position of the vertex.                                                         |
 | 0x6        | 0x2s     | Y                   | Position of the vertex.                                                         |
 | 0x8        | 0x2s     | Z                   | Position of the vertex.                                                         |
 | 0xA        | 0x2s     | Vertex palette      | Texture data is still unknown.                                                  |
 
 ## Mesh metadata
 
-This section starts with a number indicating the number of objects in the file. Each object has a high LOD mesh and a low LOD mesh (LOD = Level of Detail).
+This section starts with a number indicating the number of objects in the file. Each object has a high LOD mesh, and may or may not have a low LOD mesh (LOD = Level of Detail).
 
-| Offset (h) | Size (h) | Usage                          | Notes                                      |
-|:---------- |:-------- |:------------------------------ |:------------------------------------------ |
-| 0x0        | 0x4u     | Number of objects in the file. | Multiplying by 2 gives you the mesh count. |
+| Offset (h) | Size (h) | Usage                          | Notes |
+|:---------- |:-------- |:------------------------------ |:----- |
+| 0x0        | 0x4u     | Number of objects in the file. | N/a.  |
 
 It's followed by a data structure with size of 0x4C bytes, which contains metadata of each object.
 
 | Offset (h) | Size (h) | Usage                                         | Notes                                                |
 |:---------- |:-------- |:--------------------------------------------- |:---------------------------------------------------- |
-| 0x0        | 0x4u     | Size of the mesh (high + low LOD).            | N/a.                                                 |
+| 0x0        | 0x4u     | Offset to the end of the object halved.       | Multiplying by 2 gives the true offset in the file.  |
 | 0x4        | 0x4s     | X translation.                                | Translation applied to both high and low LOD meshes. |
 | 0x8        | 0x4s     | Y translation.                                | Translation applied to both high and low LOD meshes. |
 | 0xC        | 0x4s     | Z translation.                                | Translation applied to both high and low LOD meshes. |

src/Makefile

@@ -1,6 +1,6 @@
 CC = g++
 FLAGS = -std=c++17
-CPP_FILES = main.cpp extractor.cpp racer.cpp course.cpp raw.cpp
+CPP_FILES = main.cpp extractor.cpp racer.cpp
 PROGRAM = extractor
 
 all: $(CPP_FILES)

src/racer.cpp

@@ -22,9 +22,10 @@ void mdl_to_obj(fs::path mdl_path, fs::path output_path) {
     racer_model.read((char *) &mh, sizeof(mh));
 
     // Reading mesh metadata
-    MESH_METADATA metadata[mh.mesh_count];
-    for (int i = 0; i < mh.mesh_count; i++) {
+    MESH_METADATA metadata[mh.obj_count];
+    for (int i = 0; i < mh.obj_count; i++) {
         racer_model.read((char *) &metadata[i], sizeof(metadata[i]));
+        metadata[i].obj_size *= 2;
     }
 
     // Restoring the seek position to read the mesh data
@@ -45,11 +46,13 @@ void mdl_to_obj(fs::path mdl_path, fs::path output_path) {
     int num_vertex = 0;
     // Index to keep track of the number of meshes found
     int num_meshes = 0;
+    // Index to keep track of the number of objects found
+    int num_objects = 0;
     // Bool to keep track of when to create new meshes objects
     bool new_obj = true;
 
     // While there are vertexes bytes to be read
-    while (num_meshes < mh.mesh_count * 2) {
+    while (num_objects < mh.obj_count * 2) {
 
         /* Read the color command that goes to the GTE. They encoded
         in these bytes whether the polygon is a triangle or a quad. Also,
@@ -63,6 +66,11 @@ void mdl_to_obj(fs::path mdl_path, fs::path output_path) {
                 // If not, then the next vertex will belong to a new mesh
                 new_obj = true;
                 num_meshes++;
+                // Checking whether this object has a low LOD mesh or not
+                if (vc.r != 2) {
+                    // If not, then we move on to the next object
+                    num_objects++;
+                }
                 continue;
             }
 
@@ -86,9 +94,9 @@ void mdl_to_obj(fs::path mdl_path, fs::path output_path) {
         racer_model.read((char *) &v, sizeof(v));
         num_vertex += 1;
         output_file << "v "
-                    << ((v.x + metadata[num_meshes / 2].trans_x) * -1) / 127.0 << " "
-                    << ((v.y + metadata[num_meshes / 2].trans_y) * -1) / 127.0 << " "
-                    << ((v.z + metadata[num_meshes / 2].trans_z) * -1) / 127.0 << " "
+                    << ((v.x + metadata[num_objects].trans_x) * -1) / 127.0 << " "
+                    << ((v.y + metadata[num_objects].trans_y) * -1) / 127.0 << " "
+                    << ((v.z + metadata[num_objects].trans_z) * -1) / 127.0 << " "
                     << vc.r / 255.0 << " " << vc.g / 255.0 << " " << vc.b / 255.0 << endl;
 
         // If the vertex is the last of the face, write the face to the .obj

src/racer.h

@@ -22,11 +22,11 @@ struct VERTEX {
 };
 
 struct MESH_HEADER {
-    uint32_t mesh_count;
+    uint32_t obj_count;
 };
 
 struct MESH_METADATA {
-    uint32_t mesh_size;
+    uint32_t obj_size;
     int32_t trans_x;
     int32_t trans_y;
     int32_t trans_z;