add 'modelviewer' ui element

src/graphics/core/Batch3D.hpp

@@ -3,6 +3,7 @@
 #include "typedefs.hpp"
 #include "commons.hpp"
 #include "MeshData.hpp"
+#include "maths/UVRegion.hpp"
 
 #include <memory>
 #include <cstdlib>
@@ -32,8 +33,8 @@ class Batch3D : public Flushable {
     std::unique_ptr<Texture> blank;
     size_t index;
     glm::vec4 tint {1.0f};
-    
     const Texture* currentTexture;
+    UVRegion region {0.0f, 0.0f, 1.0f, 1.0f};
 
     void vertex(
         float x, float y, float z,
@@ -102,6 +103,8 @@ public:
         const glm::vec4& tint,
         bool shading = true
     );
+    void setRegion(UVRegion region);
+    void vertex(const glm::vec3& pos, const glm::vec2& uv, const glm::vec3& norm);
     void vertex(const glm::vec3& pos, const glm::vec2& uv, const glm::vec4& tint);
     void point(const glm::vec3& pos, const glm::vec4& tint);
     void flush() override;