.

src/obj.c

@@ -12,6 +12,7 @@ struct vertex_t {
     vec3 pos;
     vec3 norm;
     vec2 tex;
+    vec2 lightmap;
 };
 
 typedef struct material_t material_t;
@@ -282,11 +283,32 @@ struct scene_t {
     int object_count;
 };
 
+#define CACHE_SIZE (64)
+#define MAX_CACHE_NAME_LEN (64)
+
+typedef struct cache_item_t cache_item_t;
+struct cache_item_t {
+    char name[MAX_CACHE_NAME_LEN];
+    sg_image image;
+};
+cache_item_t tex_cache[CACHE_SIZE] = {0};
+
+int tex_cache_size = 0;
+
 sg_image obj__load_texture(arena_t scratch, cgltf_texture *texture) {
     if (!texture || !texture->image) {
         return (sg_image){0};
     }
+
     cgltf_image *image = texture->image;
+    const char *name = image->name;
+
+    for (int i = 0; i < tex_cache_size; ++i) {
+        if (strcmp(tex_cache[i].name, name) == 0) {
+            return tex_cache[i].image;
+        }
+    }
+
     u8 *bytes = NULL;
     usize size = 0;
     if (image->uri) {
@@ -322,6 +344,13 @@ sg_image obj__load_texture(arena_t scratch, cgltf_texture *texture) {
 
     stbi_image_free(pixels);
 
+    cache_item_t *item = &tex_cache[tex_cache_size++];
+    colla_assert(tex_cache_size < CACHE_SIZE, "texture cache full");
+
+    item->image = out;
+    usize len = strlen(name);
+    memmove(item->name, name, MIN(len, MAX_CACHE_NAME_LEN));
+
     return out;
 }
 
@@ -360,11 +389,16 @@ scene_t obj_load_gltf(arena_t scratch, strview_t filename) {
 
     colla_assert(data->meshes_count == 1);
 
-    sg_sampler sampler = sg_make_sampler(&(sg_sampler_desc){
+    sg_sampler tex_sampler = sg_make_sampler(&(sg_sampler_desc){
         .min_filter = SG_FILTER_NEAREST,
         .mag_filter = SG_FILTER_NEAREST,
     });
 
+    sg_sampler lightmap_sampler = sg_make_sampler(&(sg_sampler_desc){
+        .min_filter = SG_FILTER_LINEAR,
+        .mag_filter = SG_FILTER_LINEAR,
+    });
+
     u32 missing_texture[] = {
         0xFFFF00FF, 0x00000000,
         0x00000000, 0xFFFF00FF,
@@ -399,6 +433,7 @@ scene_t obj_load_gltf(arena_t scratch, strview_t filename) {
 
             cgltf_material *mat = prim->material;
 
+            // diffuse texture
             cgltf_texture_view texture_view = mat->pbr_metallic_roughness.base_color_texture;
             sg_image image = obj__load_texture(scratch, texture_view.texture);
             if (image.id == 0) {
@@ -407,8 +442,20 @@ scene_t obj_load_gltf(arena_t scratch, strview_t filename) {
             sg_view view = sg_make_view(&(sg_view_desc){
                 .texture.image = image,
             });
+
             obj->bindings.views[0] = view;
-            obj->bindings.samplers[0] = sampler;
+            obj->bindings.samplers[0] = tex_sampler;
+
+            // lightmap 
+            sg_image lightmap = missing_img;
+            if (mat->emissive_texture.texture) {
+                lightmap = obj__load_texture(scratch, mat->emissive_texture.texture);
+            }
+            sg_view lm_view = sg_make_view(&(sg_view_desc){
+                .texture.image = lightmap,
+            });
+            obj->bindings.views[1] = lm_view;
+            obj->bindings.samplers[1] = lightmap_sampler;
 
             for (usize a = 0; a < prim->attributes_count; ++a) {
                 cgltf_attribute *attr = &prim->attributes[a];
@@ -429,10 +476,19 @@ scene_t obj_load_gltf(arena_t scratch, strview_t filename) {
                         }
                        break;
                     case cgltf_attribute_type_texcoord:
-                        for (usize k = 0; k < acc->count; ++k) {
-                            cgltf_accessor_read_float(acc, k, verts[k].tex.data, 2);
+                    {
+                        if (attr->index == 0) {
+                            for (usize k = 0; k < acc->count; ++k) {
+                                cgltf_accessor_read_float(acc, k, verts[k].tex.data, 2);
+                            }
+                        }
+                        else {
+                            for (usize k = 0; k < acc->count; ++k) {
+                                cgltf_accessor_read_float(acc, k, verts[k].lightmap.data, 2);
+                            }
                         }
                         break;
+                    }
 
                     default: break;
                 }