Some update to gltf loading (#4373)

Only warns when there are more animations than currently implemented
Allows mesh indices to be unsigned char

src/rmodels.c

@@ -5226,17 +5226,19 @@ static Model LoadGLTF(const char *fileName)
     ***********************************************************************************************/
 
     // Macro to simplify attributes loading code
-    #define LOAD_ATTRIBUTE(accesor, numComp, dataType, dstPtr) \
+    #define LOAD_ATTRIBUTE(accesor, numComp, srcType, dstPtr) LOAD_ATTRIBUTE_CAST(accesor, numComp, srcType, dstPtr, srcType) 
+
+    #define LOAD_ATTRIBUTE_CAST(accesor, numComp, srcType, dstPtr, dstType) \
     { \
         int n = 0; \
-        dataType *buffer = (dataType *)accesor->buffer_view->buffer->data + accesor->buffer_view->offset/sizeof(dataType) + accesor->offset/sizeof(dataType); \
+        srcType *buffer = (srcType *)accesor->buffer_view->buffer->data + accesor->buffer_view->offset/sizeof(srcType) + accesor->offset/sizeof(srcType); \
         for (unsigned int k = 0; k < accesor->count; k++) \
         {\
             for (int l = 0; l < numComp; l++) \
             {\
-                dstPtr[numComp*k + l] = buffer[n + l];\
+                dstPtr[numComp*k + l] = p">(dstType)buffer[n + l];\
             }\
-            n += (int)(accesor->stride/sizeof(dataType));\
+            n += (int)(accesor->stride/sizeof(srcType));\
         }\
     }
 
@@ -5697,23 +5699,25 @@ static Model LoadGLTF(const char *fileName)
                         // Load unsigned short data type into mesh.indices
                         LOAD_ATTRIBUTE(attribute, 1, unsigned short, model.meshes[meshIndex].indices)
                     }
+                    else if (attribute->component_type == cgltf_component_type_r_8u)
+                    {
+                        // Init raylib mesh indices to copy glTF attribute data
+                        model.meshes[meshIndex].indices = RL_MALLOC(attribute->count * sizeof(unsigned short));
+                        LOAD_ATTRIBUTE_CAST(attribute, 1, unsigned char, model.meshes[meshIndex].indices, unsigned short)
+
+                    }
                     else if (attribute->component_type == cgltf_component_type_r_32u)
                     {
                         // Init raylib mesh indices to copy glTF attribute data
                         model.meshes[meshIndex].indices = RL_MALLOC(attribute->count*sizeof(unsigned short));
-
-                        // Load data into a temp buffer to be converted to raylib data type
-                        unsigned int *temp = RL_MALLOC(attribute->count*sizeof(unsigned int));
-                        LOAD_ATTRIBUTE(attribute, 1, unsigned int, temp);
-
-                        // Convert data to raylib indices data type (unsigned short)
-                        for (unsigned int d = 0; d < attribute->count; d++) model.meshes[meshIndex].indices[d] = (unsigned short)temp[d];
+                        LOAD_ATTRIBUTE_CAST(attribute, 1, unsigned int, model.meshes[meshIndex].indices, unsigned short);
 
                         TRACELOG(LOG_WARNING, "MODEL: [%s] Indices data converted from u32 to u16, possible loss of data", fileName);
-
-                        RL_FREE(temp);
                     }
-                    else TRACELOG(LOG_WARNING, "MODEL: [%s] Indices data format not supported, use u16", fileName);
+                    else 
+                    {
+                        TRACELOG(LOG_WARNING, "MODEL: [%s] Indices data format not supported, use u16", fileName);
+                    }
                 }
                 else model.meshes[meshIndex].triangleCount = model.meshes[meshIndex].vertexCount/3;    // Unindexed mesh
 
@@ -5745,7 +5749,7 @@ static Model LoadGLTF(const char *fileName)
         //  - Only supports linear interpolation (default method in Blender when checked "Always Sample Animations" when exporting a GLTF file)
         //  - Only supports translation/rotation/scale animation channel.path, weights not considered (i.e. morph targets)
         //----------------------------------------------------------------------------------------------------
-        if (data->skins_count == 1)
+        if (data->skins_count > 0)
         {
             cgltf_skin skin = data->skins[0];
             model.bones = LoadBoneInfoGLTF(skin, &model.boneCount);
@@ -5765,9 +5769,9 @@ static Model LoadGLTF(const char *fileName)
                 MatrixDecompose(worldMatrix, &(model.bindPose[i].translation), &(model.bindPose[i].rotation), &(model.bindPose[i].scale));
             }
         }
-        else if (data->skins_count > 1)
+        if (data->skins_count > 1)
         {
-            TRACELOG(LOG_ERROR, "MODEL: [%s] can only load one skin (armature) per model, but gltf skins_count == %i", fileName, data->skins_count);
+            TRACELOG(LOG_WARNING, "MODEL: [%s] can only load one skin (armature) per model, but gltf skins_count == %i", fileName, data->skins_count);
         }
 
         meshIndex = 0;
@@ -6088,7 +6092,7 @@ static ModelAnimation *LoadModelAnimationsGLTF(const char *fileName, int *animCo
 
     if (result == cgltf_result_success)
     {
-        if (data->skins_count == 1)
+        if (data->skins_count > 0)
         {
             cgltf_skin skin = data->skins[0];
             *animCount = (int)data->animations_count;
@@ -6223,7 +6227,11 @@ static ModelAnimation *LoadModelAnimationsGLTF(const char *fileName, int *animCo
                 RL_FREE(boneChannels);
             }
         }
-        else TRACELOG(LOG_ERROR, "MODEL: [%s] expected exactly one skin to load animation data from, but found %i", fileName, data->skins_count);
+        
+        if (data->skins_count > 1)
+        {
+            TRACELOG(LOG_WARNING, "MODEL: [%s] expected exactly one skin to load animation data from, but found %i", fileName, data->skins_count);
+        }
 
         cgltf_free(data);
     }