Implement spritebatch properly.

src/duskgl/display/mesh/meshgl.c

@@ -21,9 +21,10 @@ errorret_t meshInitGL(
 
   mesh->primitiveType = primitiveType;
   mesh->vertexCount = vertexCount;
+  mesh->vertices = vertices;
 
   #ifdef DUSK_OPENGL_LEGACY
-    mesh->vertices = vertices;
+    // Nothing needed.
   #else
     // Generate Vertex Buffer Object
     glGenBuffers(1, &mesh->vboId);
@@ -34,7 +35,7 @@ errorret_t meshInitGL(
       GL_ARRAY_BUFFER,
       vertexCount * sizeof(meshvertex_t),
       vertices,
-      GL_STATIC_DRAW
+      GL_DYNAMIC_DRAW
     );
     errorChain(errorGLCheck());
 
@@ -93,6 +94,27 @@ errorret_t meshInitGL(
   errorOk();
 }
 
+errorret_t meshFlushGL(
+  meshgl_t *mesh,
+  const int32_t vertOffset,
+  const int32_t vertCount
+) {
+  #ifdef DUSK_OPENGL_LEGACY
+    // Nothing doing, we use the glClientState stuff.
+  #else
+    glBindBuffer(GL_ARRAY_BUFFER, mesh->vboId);
+    errorChain(errorGLCheck());
+    glBufferData(
+      GL_ARRAY_BUFFER,
+      vertCount * sizeof(meshvertex_t),
+      &mesh->vertices[vertOffset],
+      GL_DYNAMIC_DRAW
+    );
+    errorChain(errorGLCheck());
+  #endif
+  errorOk();
+}
+
 errorret_t meshDrawGL(
   const meshgl_t *mesh,
   const int32_t offset,