added comments to render-related structs

src/corelib/render.h

@@ -20,41 +20,46 @@ typedef enum drawcmdtype_t {
 
 typedef struct spritesheet_t {
 	SDL_Texture* texture;
-	int w, h;
-	int tile_width, tile_height;
-} spritesheet_t;
+	int w, h;						// width and height of texture
+	int tile_width, tile_height;	// the width and height of each tile of each
+} spritesheet_t;					// sliced up sheet of sprites
+
+typedef struct nineslice_t {
+	SDL_Texture* texture;
+	float corner_height, corner_width;	// the width and height of the corners
+} nineslice_t;							// nine-sliced texture for ui
 
 typedef struct sprite_t {
 	SDL_Texture* texture;
-	float x, y;
-	SDL_FPoint origin;
-	float sx, sy;
-	float rot;
-	depth_t depth;
-	SDL_Rect uv;
-} sprite_t;
+	float x, y;				// positions of x,y
+	SDL_FPoint origin;		// the origin point on the sprite
+	float sx, sy;			// the x and y scale of the sprite
+	float rot;				// rotation around origin of the sprite
+	depth_t depth;			// depth to render at, lower is on top, higher is on bottom
+	SDL_Rect uv;			// the source rect to render from the texture
+} sprite_t;					// a drawable and transformable texture sprite
 
 typedef struct rectshape_t {
-	float x, y, w, h;
-	float line_width;
-	int depth;
-	SDL_Color background;
-	SDL_Color line;
-} rectshape_t;
+	float x, y, w, h;		// the top-left, width and height of a rect
+	float line_width;		// the width of the lines
+	int depth;				// the depth to render at, lower is on top, higher is on bottom
+	SDL_Color background;	// the colour of the background
+	SDL_Color line;			// the colour of the line
+} rectshape_t;				// a drawable rectangle with outline and background
 
 typedef struct drawcmd_t {
-	drawcmdtype_t type;
-	depth_t depth;
-	short ui;
+	drawcmdtype_t type;		// the thing to render
+	depth_t depth;			// the depth to render at
+	short ui;				// 0 if this should be rendered in world space, 1 if this should be rendered in ui space
 	union {
-		sprite_t sprite;
-		rectshape_t rect;
+		sprite_t sprite;	// if type is sprite, render this
+		rectshape_t rect;	// if type is rect, render this
 	};
-} drawcmd_t;
+} drawcmd_t;				// an orderable command to render, should not be directly used, use draw_* functions instead
 
 typedef struct view_t {
-	float x, y;
-	float width;
+	float x, y;				// the x,y position of the centre of the screen
+	float width;			// the width of the camera
 } view_t;
 
 extern int _render_mode;