Added instancing support to Meshes via Mesh:setInstanceCount. Added a new built-in variable to vertex shaders: int love_InstanceID.

love.graphics.draw(mesh) will draw the mesh instancecount times, using hardware instancing when available. The only way to draw individual instances differently from each other is to use the love_InstanceID variable in a vertex shader.

Added love.graphics.isSupported(“instancing”). Hardware instancing is supported if true, otherwise a (slower) pseudo-instancing fallback is used internally when drawing instanced meshes.

src/modules/graphics/opengl/Mesh.h

@@ -109,6 +109,15 @@ public:
 	 **/
 	size_t getVertexMapCount() const;
 
+	/**
+	 * Sets the number of instances of this Mesh to draw (uses hardware
+	 * instancing when possible.)
+	 * A custom vertex shader is necessary in order to introduce differences
+	 * in each instance.
+	 **/
+	void setInstanceCount(int count);
+	int getInstanceCount() const;
+
 	/**
 	 * Sets the texture used when drawing the Mesh.
 	 **/
@@ -165,6 +174,8 @@ private:
 	VertexBuffer *ibo;
 	size_t element_count;
 
+	int instance_count;
+
 	DrawMode draw_mode;
 
 	Texture *texture;