feat: display a handheld item in first-person view (WIP)

src/graphics/render/ModelBatch.cpp

@@ -77,6 +77,7 @@ void ModelBatch::draw(const model::Mesh& mesh, const glm::mat4& matrix,
                       const texture_names_map* varTextures,
                       bool backlight) {
     glm::vec3 gpos = matrix * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+    gpos += lightsOffset;
     light_t light = chunks->getLight(
         std::floor(gpos.x), 
         std::floor(std::min(CHUNK_H-1.0f, gpos.y)), 
@@ -137,6 +138,10 @@ void ModelBatch::render() {
     entries.clear();
 }
 
+void ModelBatch::setLightsOffset(const glm::vec3& offset) {
+    lightsOffset = offset;
+}
+
 void ModelBatch::setTexture(const std::string& name,
                             const texture_names_map* varTextures) {
     if (name.at(0) == '$') {