Merge pull request #124 from romainguy/rg/KHR_materials_specular

Add support for KHR_materials_specular

README.md

@@ -106,6 +106,7 @@ cgltf also supports some glTF extensions:
 - KHR_materials_clearcoat
 - KHR_materials_ior
 - KHR_materials_pbrSpecularGlossiness
+- KHR_materials_specular
 - KHR_materials_transmission
 - KHR_materials_unlit
 - KHR_texture_transform

cgltf.h

@@ -408,6 +408,13 @@ typedef struct cgltf_ior
 	cgltf_float ior;
 } cgltf_ior;
 
+typedef struct cgltf_specular
+{
+	cgltf_texture_view specular_texture;
+	cgltf_float specular_color_factor[3];
+	cgltf_float specular_factor;
+} cgltf_specular;
+
 typedef struct cgltf_material
 {
 	char* name;
@@ -416,10 +423,12 @@ typedef struct cgltf_material
 	cgltf_bool has_clearcoat;
 	cgltf_bool has_transmission;
 	cgltf_bool has_ior;
+	cgltf_bool has_specular;
 	cgltf_pbr_metallic_roughness pbr_metallic_roughness;
 	cgltf_pbr_specular_glossiness pbr_specular_glossiness;
 	cgltf_clearcoat clearcoat;
 	cgltf_ior ior;
+	cgltf_specular specular;
 	cgltf_transmission transmission;
 	cgltf_texture_view normal_texture;
 	cgltf_texture_view occlusion_texture;
@@ -1661,6 +1670,10 @@ void cgltf_free(cgltf_data* data)
 			cgltf_free_extensions(data, data->materials[i].clearcoat.clearcoat_roughness_texture.extensions, data->materials[i].clearcoat.clearcoat_roughness_texture.extensions_count);
 			cgltf_free_extensions(data, data->materials[i].clearcoat.clearcoat_normal_texture.extensions, data->materials[i].clearcoat.clearcoat_normal_texture.extensions_count);
 		}
+		if(data->materials[i].has_specular)
+		{
+			cgltf_free_extensions(data, data->materials[i].specular.specular_texture.extensions, data->materials[i].specular.specular_texture.extensions_count);
+		}
 		if(data->materials[i].has_transmission)
 		{
 			cgltf_free_extensions(data, data->materials[i].transmission.transmission_texture.extensions, data->materials[i].transmission.transmission_texture.extensions_count);
@@ -3288,6 +3301,9 @@ static int cgltf_parse_json_ior(jsmntok_t const* tokens, int i, const uint8_t* j
 	int size = tokens[i].size;
 	++i;
 
+	// Default values
+	out_ior->ior = 1.5f;
+
 	for (int j = 0; j < size; ++j)
 	{
 		CGLTF_CHECK_KEY(tokens[i]);
@@ -3312,6 +3328,48 @@ static int cgltf_parse_json_ior(jsmntok_t const* tokens, int i, const uint8_t* j
 	return i;
 }
 
+static int cgltf_parse_json_specular(cgltf_options* options, jsmntok_t const* tokens, int i, const uint8_t* json_chunk, cgltf_specular* out_specular)
+{
+	CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_OBJECT);
+	int size = tokens[i].size;
+	++i;
+
+	// Default values
+	out_specular->specular_factor = 1.0f;
+	cgltf_fill_float_array(out_specular->specular_color_factor, 3, 1.0f);
+
+	for (int j = 0; j < size; ++j)
+	{
+		CGLTF_CHECK_KEY(tokens[i]);
+
+		if (cgltf_json_strcmp(tokens+i, json_chunk, "specularFactor") == 0)
+		{
+			++i;
+			out_specular->specular_factor = cgltf_json_to_float(tokens + i, json_chunk);
+			++i;
+		}
+		else if (cgltf_json_strcmp(tokens+i, json_chunk, "specularColorFactor") == 0)
+		{
+			i = cgltf_parse_json_float_array(tokens, i + 1, json_chunk, out_specular->specular_color_factor, 3);
+		}
+		else if (cgltf_json_strcmp(tokens+i, json_chunk, "specularTexture") == 0)
+		{
+			i = cgltf_parse_json_texture_view(options, tokens, i + 1, json_chunk, &out_specular->specular_texture);
+		}
+		else
+		{
+			i = cgltf_skip_json(tokens, i+1);
+		}
+
+		if (i < 0)
+		{
+			return i;
+		}
+	}
+
+	return i;
+}
+
 static int cgltf_parse_json_transmission(cgltf_options* options, jsmntok_t const* tokens, int i, const uint8_t* json_chunk, cgltf_transmission* out_transmission)
 {
 	CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_OBJECT);
@@ -3638,6 +3696,11 @@ static int cgltf_parse_json_material(cgltf_options* options, jsmntok_t const* to
 					out_material->has_ior = 1;
 					i = cgltf_parse_json_ior(tokens, i + 1, json_chunk, &out_material->ior);
 				}
+				else if (cgltf_json_strcmp(tokens+i, json_chunk, "KHR_materials_specular") == 0)
+				{
+					out_material->has_specular = 1;
+					i = cgltf_parse_json_specular(options, tokens, i + 1, json_chunk, &out_material->specular);
+				}
 				else if (cgltf_json_strcmp(tokens+i, json_chunk, "KHR_materials_transmission") == 0)
 				{
 					out_material->has_transmission = 1;
@@ -5242,6 +5305,8 @@ static int cgltf_fixup_pointers(cgltf_data* data)
 		CGLTF_PTRFIXUP(data->materials[i].clearcoat.clearcoat_roughness_texture.texture, data->textures, data->textures_count);
 		CGLTF_PTRFIXUP(data->materials[i].clearcoat.clearcoat_normal_texture.texture, data->textures, data->textures_count);
 
+		CGLTF_PTRFIXUP(data->materials[i].specular.specular_texture.texture, data->textures, data->textures_count);
+
 		CGLTF_PTRFIXUP(data->materials[i].transmission.transmission_texture.texture, data->textures, data->textures_count);
 	}
 

cgltf_write.h

@@ -76,7 +76,8 @@ cgltf_size cgltf_write(const cgltf_options* options, char* buffer, cgltf_size si
 #define CGLTF_EXTENSION_FLAG_DRACO_MESH_COMPRESSION (1 << 4)
 #define CGLTF_EXTENSION_FLAG_MATERIALS_CLEARCOAT    (1 << 5)
 #define CGLTF_EXTENSION_FLAG_MATERIALS_IOR          (1 << 6)
-#define CGLTF_EXTENSION_FLAG_MATERIALS_TRANSMISSION (1 << 7)
+#define CGLTF_EXTENSION_FLAG_MATERIALS_SPECULAR     (1 << 7)
+#define CGLTF_EXTENSION_FLAG_MATERIALS_TRANSMISSION (1 << 8)
 
 typedef struct {
 	char* buffer;
@@ -514,6 +515,11 @@ static void cgltf_write_material(cgltf_write_context* context, const cgltf_mater
 		context->extension_flags |= CGLTF_EXTENSION_FLAG_MATERIALS_IOR;
 	}
 
+	if (material->has_specular)
+	{
+		context->extension_flags |= CGLTF_EXTENSION_FLAG_MATERIALS_SPECULAR;
+	}
+
 	if (material->has_pbr_metallic_roughness)
 	{
 		const cgltf_pbr_metallic_roughness* params = &material->pbr_metallic_roughness;
@@ -530,7 +536,7 @@ static void cgltf_write_material(cgltf_write_context* context, const cgltf_mater
 		cgltf_write_line(context, "}");
 	}
 
-	if (material->unlit || material->has_pbr_specular_glossiness || material->has_clearcoat || material->has_ior || material->has_transmission)
+	if (material->unlit || material->has_pbr_specular_glossiness || material->has_clearcoat || material->has_ior || material->has_specular || material->has_transmission)
 	{
 		cgltf_write_line(context, "\"extensions\": {");
 		if (material->has_clearcoat)
@@ -551,6 +557,18 @@ static void cgltf_write_material(cgltf_write_context* context, const cgltf_mater
 			cgltf_write_floatprop(context, "ior", params->ior, 1.5f);
 			cgltf_write_line(context, "}");
 		}
+		if (material->has_specular)
+		{
+			const cgltf_specular* params = &material->specular;
+			cgltf_write_line(context, "\"KHR_materials_specular\": {");
+			CGLTF_WRITE_TEXTURE_INFO("specularTexture", params->specular_texture);
+			cgltf_write_floatprop(context, "specularFactor", params->specular_factor, 1.0f);
+			if (cgltf_check_floatarray(params->specular_color_factor, 3, 1.0f))
+			{
+				cgltf_write_floatarrayprop(context, "specularColorFactor", params->specular_color_factor, 3);
+			}
+			cgltf_write_line(context, "}");
+		}
 		if (material->has_transmission)
 		{
 			const cgltf_transmission* params = &material->transmission;
@@ -930,6 +948,9 @@ static void cgltf_write_extensions(cgltf_write_context* context, uint32_t extens
 	if (extension_flags & CGLTF_EXTENSION_FLAG_MATERIALS_IOR) {
 		cgltf_write_stritem(context, "KHR_materials_ior");
 	}
+	if (extension_flags & CGLTF_EXTENSION_FLAG_MATERIALS_SPECULAR) {
+		cgltf_write_stritem(context, "KHR_materials_specular");
+	}
 	if (extension_flags & CGLTF_EXTENSION_FLAG_MATERIALS_TRANSMISSION) {
 		cgltf_write_stritem(context, "KHR_materials_transmission");
 	}