openttd/src/blitter/base.hpp

/* $Id$ */

/** @file base.hpp Base for all blitters. */

#ifndef BLITTER_BASE_HPP
#define BLITTER_BASE_HPP

#include "../spritecache.h"
#include "../spriteloader/spriteloader.hpp"
#include "../zoom_type.h"

enum BlitterMode {
	BM_NORMAL,
	BM_COLOUR_REMAP,
	BM_TRANSPARENT,
};

/**
 * How all blitters should look like. Extend this class to make your own.
 */
class Blitter {
public:
	struct BlitterParams {
		const void *sprite;      ///< Pointer to the sprite how ever the encoder stored it
		const byte *remap;       ///< XXX -- Temporary storage for remap array

		int skip_left, skip_top; ///< How much pixels of the source to skip on the left and top (based on zoom of dst)
		int width, height;       ///< The width and height in pixels that needs to be drawn to dst
		int sprite_width;        ///< Real width of the sprite
		int sprite_height;       ///< Real height of the sprite
		int left, top;           ///< The offset in the 'dst' in pixels to start drawing

		void *dst;               ///< Destination buffer
		int pitch;               ///< The pitch of the destination buffer
	};

	enum PaletteAnimation {
		PALETTE_ANIMATION_NONE,           ///< No palette animation
		PALETTE_ANIMATION_VIDEO_BACKEND,  ///< Palette animation should be done by video backend (8bpp only!)
		PALETTE_ANIMATION_BLITTER,        ///< The blitter takes care of the palette animation
	};

	typedef void *AllocatorProc(size_t size);

	/**
	 * Get the screen depth this blitter works for.
	 *  This is either: 8, 16, 24 or 32.
	 */
	virtual uint8 GetScreenDepth() = 0;

	/**
	 * Draw an image to the screen, given an amount of params defined above.
	 */
	virtual void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom) = 0;

	/**
	 * Draw a colortable to the screen. This is: the color of the screen is read
	 *  and is looked-up in the palette to match a new color, which then is put
	 *  on the screen again.
	 * @param dst the destination pointer (video-buffer).
	 * @param width the width of the buffer.
	 * @param height the height of the buffer.
	 * @param pal the palette to use.
	 */
	virtual void DrawColorMappingRect(void *dst, int width, int height, int pal) = 0;

	/**
	 * Convert a sprite from the loader to our own format.
	 */
	virtual Sprite *Encode(SpriteLoader::Sprite *sprite, Blitter::AllocatorProc *allocator) = 0;

	/**
	 * Move the destination pointer the requested amount x and y, keeping in mind
	 *  any pitch and bpp of the renderer.
	 * @param video The destination pointer (video-buffer) to scroll.
	 * @param x How much you want to scroll to the right.
	 * @param y How much you want to scroll to the bottom.
	 * @return A new destination pointer moved the the requested place.
	 */
	virtual void *MoveTo(const void *video, int x, int y) = 0;

	/**
	 * Draw a pixel with a given color on the video-buffer.
	 * @param video The destination pointer (video-buffer).
	 * @param x The x position within video-buffer.
	 * @param y The y position within video-buffer.
	 * @param color A 8bpp mapping color.
	 */
	virtual void SetPixel(void *video, int x, int y, uint8 color) = 0;

	/**
	 * Draw a pixel with a given color on the video-buffer if there is currently a black pixel.
	 * @param video The destination pointer (video-buffer).
	 * @param x The x position within video-buffer.
	 * @param y The y position within video-buffer.
	 * @param color A 8bpp mapping color.
	 */
	virtual void SetPixelIfEmpty(void *video, int x, int y, uint8 color) = 0;

	/**
	 * Make a single horizontal line in a single color on the video-buffer.
	 * @param video The destination pointer (video-buffer).
	 * @param width The lenght of the line.
	 * @param color A 8bpp mapping color.
	 */
	virtual void DrawRect(void *video, int width, int height, uint8 color) = 0;

	/**
	 * Draw a line with a given color.
	 * @param video The destination pointer (video-buffer).
	 * @param x The x coordinate from where the line starts.
	 * @param y The y coordinate from where the line starts.
	 * @param x2 The x coordinate to where the line goes.
	 * @param y2 The y coordinate to where the lines goes.
	 * @param screen_width The width of the screen you are drawing in (to avoid buffer-overflows).
	 * @param screen_height The height of the screen you are drawing in (to avoid buffer-overflows).
	 * @param color A 8bpp mapping color.
	 */
	virtual void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 color) = 0;

	/**
	 * Copy from a buffer to the screen.
	 * @param video The destionation pointer (video-buffer).
	 * @param src The buffer from which the data will be read.
	 * @param width The width of the buffer.
	 * @param height The height of the buffer.
	 * @note You can not do anything with the content of the buffer, as the blitter can store non-pixel data in it too!
	 */
	virtual void CopyFromBuffer(void *video, const void *src, int width, int height) = 0;

	/**
	 * Copy from the screen to a buffer.
	 * @param video The destination pointer (video-buffer).
	 * @param dst The buffer in which the data will be stored.
	 * @param width The width of the buffer.
	 * @param height The height of the buffer.
	 * @note You can not do anything with the content of the buffer, as the blitter can store non-pixel data in it too!
	 */
	virtual void CopyToBuffer(const void *video, void *dst, int width, int height) = 0;

	/**
	 * Copy from the screen to a buffer in a palette format for 8bpp and RGBA format for 32bpp.
	 * @param video The destination pointer (video-buffer).
	 * @param dst The buffer in which the data will be stored.
	 * @param width The width of the buffer.
	 * @param height The height of the buffer.
	 * @param dst_pitch The pitch (byte per line) of the destination buffer.
	 */
	virtual void CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch) = 0;

	/**
	 * Scroll the videobuffer some 'x' and 'y' value.
	 * @param video The buffer to scroll into.
	 * @param left The left value of the screen to scroll.
	 * @param top The top value of the screen to scroll.
	 * @param width The width of the screen to scroll.
	 * @param height The height of the screen to scroll.
	 * @param scroll_x How much to scroll in X.
	 * @param scroll_y How much to scroll in Y.
	 */
	virtual void ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y) = 0;

	/**
	 * Calculate how much memory there is needed for an image of this size in the video-buffer.
	 * @param width The width of the buffer-to-be.
	 * @param height The height of the buffer-to-be.
	 * @return The size needed for the buffer.
	 */
	virtual int BufferSize(int width, int height) = 0;

	/**
	 * Called when the 8bpp palette is changed; you should redraw all pixels on the screen that
	 *  are equal to the 8bpp palette indexes 'start' to 'start + count'.
	 * @param start The start index in the 8bpp palette.
	 * @param count The amount of indexes that are (possible) changed.
	 */
	virtual void PaletteAnimate(uint start, uint count) = 0;

	/**
	 * Check if the blitter uses palette animation at all.
	 * @return True if it uses palette animation.
	 */
	virtual Blitter::PaletteAnimation UsePaletteAnimation() = 0;

	/**
	 * Get the name of the blitter, the same as the Factory-instance returns.
	 */
	virtual const char *GetName() = 0;

	/**
	 * Get how many bytes are needed to store a pixel.
	 */
	virtual int GetBytesPerPixel() = 0;

	virtual ~Blitter() { }
};

#endif /* BLITTER_BASE_HPP */