Common structures:

typedef float[4][4] MATRIX;	Stored in OpenGL format (not transposed like in D3D)

typedef struct {
	float x,y,z;
	float nx,ny,nz;	Normal
	float u,v;	Texture coords (D3D wants these float)
	UINT32 color;
} VERTEX;

typedef struct {
	int v[4];	Vertex indices
	int texture;	Texture index in cache
	int flags;	Polygon flags (mirroring, etc.)
	int transparency;
	int luminance;
	
	...   Everything else I forgot to add...
} POLYGON;

The polygon entries are changed into more hardware-friendly format in the renderer
(sorting by textures to avoid expensive state-changes, etc.) This works with
VROM-models, but not with dynamic vertex data.



osd_renderer_init(all those r3d memory addresses)
	should we give the Win32 HWND as an osd-independent param (void*) ?????
	all those mem addresses in a single struct ????

osd_renderer_shutdown(void)
	


osd_renderer_set_mode(bool fullscreen, int width, int height)

osd_renderer_unset_mode(void)
	return to windowed mode ?

osd_renderer_update_frame(void)
	draw the already rendered frame

osd_renderer_get_layer_buffer(int, UINT8**, UINT*)
osd_renderer_free_layer_buffer(int)
osd_renderer_get_layer_format(struct* format)
	to remove the two-way dependency from renderer and tilegen.
	We shouldn't have a call to tilegen from the renderer.

osd_renderer_remove_textures(UINT, UINT, UINT, UINT)
	or could the correct name be something like invalidate_cached_texture ?


osd_renderer_clear(...)
	clear the frame

osd_renderer_render_layer(int layer)
	render a 2d layer

osd_renderer_begin_scene()
osd_renderer_end_scene()
	D3D needs to call begin_scene and end_scene before and after rendering the scene


osd_renderer_push_matrix(MATRIX)
osd_renderer_pop_matrix()
osd_renderer_matrix_multiply(MATRIX)
osd_renderer_matrix_translate(x,y,z)
osd_renderer_empty_matrix_stack()
	Matrix stack operations

osd_renderer_set_fog(struct FOG_PARAMS)
osd_renderer_set_viewport(struct VIEWPORT_PARAMS)
osd_renderer_set_projection(projection params)
osd_renderer_set_coord_sys(MATRIX)

osd_renderer_set_light(int light_num,struct LIGHT_PARAMS)

osd_renderer_cache_model(POLYGON array, VERTEX array)
	maybe use the the address as a hash table key ???

osd_renderer_render_model(...)
	draw a model. use the address to check if the model is already in cache.
	We also need a way to render non-cached models (dynamic vertex data).
	That will be hard to get fast.