include/SDL_surface.h
changeset 2275 12ea0fdc0df2
child 2807 365fe1a2aad5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/SDL_surface.h	Mon Sep 10 12:20:02 2007 +0000
@@ -0,0 +1,488 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997-2006 Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Lesser General Public
+    License as published by the Free Software Foundation; either
+    version 2.1 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+    Sam Lantinga
+    slouken@libsdl.org
+*/
+
+/**
+ * \file SDL_surface.h
+ *
+ * Header file for SDL_surface definition and management functions
+ */
+
+#ifndef _SDL_surface_h
+#define _SDL_surface_h
+
+#include "SDL_stdinc.h"
+#include "SDL_pixels.h"
+#include "SDL_rect.h"
+#include "SDL_rwops.h"
+
+#include "begin_code.h"
+/* Set up for C function definitions, even when using C++ */
+#ifdef __cplusplus
+/* *INDENT-OFF* */
+extern "C" {
+/* *INDENT-ON* */
+#endif
+
+/* These are the currently supported flags for the SDL_surface */
+/* Used internally (read-only) */
+#define SDL_PREALLOC        0x00000001  /* Surface uses preallocated memory */
+#define SDL_RLEACCEL        0x00000002  /* Surface is RLE encoded */
+
+/* Evaluates to true if the surface needs to be locked before access */
+#define SDL_MUSTLOCK(S)	(((S)->flags & SDL_RLEACCEL) != 0)
+
+/**
+ * \struct SDL_Surface
+ *
+ * \brief A collection of pixels used in software blitting
+ *
+ * \note  This structure should be treated as read-only, except for 'pixels',
+ *        which, if not NULL, contains the raw pixel data for the surface.
+ */
+typedef struct SDL_Surface
+{
+    Uint32 flags;               /**< Read-only */
+    SDL_PixelFormat *format;    /**< Read-only */
+    int w, h;                   /**< Read-only */
+    int pitch;                  /**< Read-only */
+    void *pixels;               /**< Read-write */
+
+    /* Application data associated with the surfade */
+    void *userdata;             /**< Read-write */
+
+    /* information needed for surfaces requiring locks */
+    int locked;                 /**< Read-only */
+    void *lock_data;            /**< Read-only */
+
+    /* clipping information */
+    SDL_Rect clip_rect;         /**< Read-only */
+
+    /* info for fast blit mapping to other surfaces */
+    struct SDL_BlitMap *map;    /**< Private */
+
+    /* format version, bumped at every change to invalidate blit maps */
+    unsigned int format_version;        /**< Private */
+
+    /* Reference count -- used when freeing surface */
+    int refcount;               /**< Read-mostly */
+} SDL_Surface;
+
+/**
+ * \typedef SDL_blit
+ *
+ * \brief The type of function used for surface blitting functions
+ */
+typedef int (*SDL_blit) (struct SDL_Surface * src, SDL_Rect * srcrect,
+                         struct SDL_Surface * dst, SDL_Rect * dstrect);
+
+/*
+ * Allocate and free an RGB surface (must be called after SDL_SetVideoMode)
+ * If the depth is 4 or 8 bits, an empty palette is allocated for the surface.
+ * If the depth is greater than 8 bits, the pixel format is set using the
+ * flags '[RGB]mask'.
+ * If the function runs out of memory, it will return NULL.
+ *
+ * The 'flags' tell what kind of surface to create.
+ * SDL_SRCCOLORKEY indicates that the surface will be used for colorkey blits.
+ * SDL_SRCALPHA means that the surface will be used for alpha blits.
+ */
+extern DECLSPEC SDL_Surface *SDLCALL SDL_CreateRGBSurface
+    (Uint32 flags, int width, int height, int depth,
+     Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
+extern DECLSPEC SDL_Surface *SDLCALL SDL_CreateRGBSurfaceFrom(void *pixels,
+                                                              int width,
+                                                              int height,
+                                                              int depth,
+                                                              int pitch,
+                                                              Uint32 Rmask,
+                                                              Uint32 Gmask,
+                                                              Uint32 Bmask,
+                                                              Uint32 Amask);
+extern DECLSPEC void SDLCALL SDL_FreeSurface(SDL_Surface * surface);
+
+/**
+ * \fn int SDL_SetSurfacePalette(SDL_Surface *surface, SDL_Palette *palette)
+ *
+ * \brief Set the palette used by a surface.
+ *
+ * \return 0, or -1 if the surface format doesn't use a palette.
+ *
+ * \note A single palette can be shared with many surfaces.
+ */
+extern DECLSPEC int SDLCALL SDL_SetSurfacePalette(SDL_Surface * surface,
+                                                  SDL_Palette * palette);
+
+/*
+ * SDL_LockSurface() sets up a surface for directly accessing the pixels.
+ * Between calls to SDL_LockSurface()/SDL_UnlockSurface(), you can write
+ * to and read from 'surface->pixels', using the pixel format stored in 
+ * 'surface->format'.  Once you are done accessing the surface, you should 
+ * use SDL_UnlockSurface() to release it.
+ *
+ * Not all surfaces require locking.  If SDL_MUSTLOCK(surface) evaluates
+ * to 0, then you can read and write to the surface at any time, and the
+ * pixel format of the surface will not change.
+ * 
+ * No operating system or library calls should be made between lock/unlock
+ * pairs, as critical system locks may be held during this time.
+ *
+ * SDL_LockSurface() returns 0, or -1 if the surface couldn't be locked.
+ */
+extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface * surface);
+extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface * surface);
+
+/*
+ * Load a surface from a seekable SDL data source (memory or file.)
+ * If 'freesrc' is non-zero, the source will be closed after being read.
+ * Returns the new surface, or NULL if there was an error.
+ * The new surface should be freed with SDL_FreeSurface().
+ */
+extern DECLSPEC SDL_Surface *SDLCALL SDL_LoadBMP_RW(SDL_RWops * src,
+                                                    int freesrc);
+
+/* Convenience macro -- load a surface from a file */
+#define SDL_LoadBMP(file)	SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)
+
+/*
+ * Save a surface to a seekable SDL data source (memory or file.)
+ * If 'freedst' is non-zero, the source will be closed after being written.
+ * Returns 0 if successful or -1 if there was an error.
+ */
+extern DECLSPEC int SDLCALL SDL_SaveBMP_RW
+    (SDL_Surface * surface, SDL_RWops * dst, int freedst);
+
+/* Convenience macro -- save a surface to a file */
+#define SDL_SaveBMP(surface, file) \
+		SDL_SaveBMP_RW(surface, SDL_RWFromFile(file, "wb"), 1)
+
+/*
+ * \fn int SDL_SetSurfaceRLE(SDL_Surface *surface, int flag)
+ *
+ * \brief Sets the RLE acceleration hint for a surface.
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \note If RLE is enabled, colorkey and alpha blending blits are much faster,
+ *       but the surface must be locked before directly accessing the pixels.
+ */
+extern DECLSPEC int SDLCALL SDL_SetSurfaceRLE(SDL_Surface * surface,
+                                              int flag);
+
+/*
+ * \fn int SDL_SetColorKey(SDL_Surface *surface, Uint32 flag, Uint32 key)
+ *
+ * \brief Sets the color key (transparent pixel) in a blittable surface.
+ *
+ * \param surface The surface to update
+ * \param flag Non-zero to enable colorkey and 0 to disable colorkey 
+ * \param key The transparent pixel in the native surface format
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ */
+extern DECLSPEC int SDLCALL SDL_SetColorKey(SDL_Surface * surface,
+                                            Uint32 flag, Uint32 key);
+
+/**
+ * \fn int SDL_SetSurfaceColorMod(SDL_Surface *surface, Uint8 r, Uint8 g, Uint8 b)
+ *
+ * \brief Set an additional color value used in blit operations
+ *
+ * \param surface The surface to update
+ * \param r The red source color value multiplied into blit operations
+ * \param g The green source color value multiplied into blit operations
+ * \param b The blue source color value multiplied into blit operations
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \sa SDL_GetSurfaceColorMod()
+ */
+extern DECLSPEC int SDLCALL SDL_SetSurfaceColorMod(SDL_Surface * surface,
+                                                   Uint8 r, Uint8 g, Uint8 b);
+
+
+/**
+ * \fn int SDL_GetSurfaceColorMod(SDL_Surface *surface, Uint8 *r, Uint8 *g, Uint8 *b)
+ *
+ * \brief Get the additional color value used in blit operations
+ *
+ * \param surface The surface to query
+ * \param r A pointer filled in with the source red color value
+ * \param g A pointer filled in with the source green color value
+ * \param b A pointer filled in with the source blue color value
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \sa SDL_SetSurfaceColorMod()
+ */
+extern DECLSPEC int SDLCALL SDL_GetSurfaceColorMod(SDL_Surface * surface,
+                                                   Uint8 * r, Uint8 * g,
+                                                   Uint8 * b);
+
+/**
+ * \fn int SDL_SetSurfaceAlphaMod(SDL_Surface *surface, Uint8 alpha)
+ *
+ * \brief Set an additional alpha value used in blit operations
+ *
+ * \param surface The surface to update
+ * \param alpha The source alpha value multiplied into blit operations.
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \sa SDL_GetSurfaceAlphaMod()
+ */
+extern DECLSPEC int SDLCALL SDL_SetSurfaceAlphaMod(SDL_Surface * surface,
+                                                   Uint8 alpha);
+
+/**
+ * \fn int SDL_GetSurfaceAlphaMod(SDL_Surface *surface, Uint8 *alpha)
+ *
+ * \brief Get the additional alpha value used in blit operations
+ *
+ * \param surface The surface to query
+ * \param alpha A pointer filled in with the source alpha value
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \sa SDL_SetSurfaceAlphaMod()
+ */
+extern DECLSPEC int SDLCALL SDL_GetSurfaceAlphaMod(SDL_Surface * surface,
+                                                   Uint8 * alpha);
+
+/**
+ * \fn int SDL_SetSurfaceBlendMode(SDL_Surface *surface, int blendMode)
+ *
+ * \brief Set the blend mode used for blit operations
+ *
+ * \param surface The surface to update
+ * \param blendMode SDL_TextureBlendMode to use for blit blending
+ *
+ * \return 0 on success, or -1 if the parameters are not valid
+ *
+ * \sa SDL_GetSurfaceBlendMode()
+ */
+extern DECLSPEC int SDLCALL SDL_SetSurfaceBlendMode(SDL_Surface * surface,
+                                                    int blendMode);
+
+/**
+ * \fn int SDL_GetSurfaceBlendMode(SDL_Surface *surface, int *blendMode)
+ *
+ * \brief Get the blend mode used for blit operations
+ *
+ * \param surface The surface to query
+ * \param blendMode A pointer filled in with the current blend mode
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \sa SDL_SetSurfaceBlendMode()
+ */
+extern DECLSPEC int SDLCALL SDL_GetSurfaceBlendMode(SDL_Surface * surface,
+                                                    int *blendMode);
+
+/**
+ * \fn int SDL_SetSurfaceScaleMode(SDL_Surface *surface, int scaleMode)
+ *
+ * \brief Set the scale mode used for blit operations
+ *
+ * \param surface The surface to update
+ * \param scaleMode SDL_TextureScaleMode to use for blit scaling
+ *
+ * \return 0 on success, or -1 if the surface is not valid or the scale mode is not supported
+ *
+ * \note If the scale mode is not supported, the closest supported mode is chosen.  Currently only SDL_TEXTURESCALEMODE_FAST is supported on surfaces.
+ *
+ * \sa SDL_GetSurfaceScaleMode()
+ */
+extern DECLSPEC int SDLCALL SDL_SetSurfaceScaleMode(SDL_Surface * surface,
+                                                    int scaleMode);
+
+/**
+ * \fn int SDL_GetSurfaceScaleMode(SDL_Surface *surface, int *scaleMode)
+ *
+ * \brief Get the scale mode used for blit operations
+ *
+ * \param surface The surface to query
+ * \param scaleMode A pointer filled in with the current scale mode
+ *
+ * \return 0 on success, or -1 if the surface is not valid
+ *
+ * \sa SDL_SetSurfaceScaleMode()
+ */
+extern DECLSPEC int SDLCALL SDL_GetSurfaceScaleMode(SDL_Surface * surface,
+                                                    int *scaleMode);
+
+/*
+ * Sets the clipping rectangle for the destination surface in a blit.
+ *
+ * If the clip rectangle is NULL, clipping will be disabled.
+ * If the clip rectangle doesn't intersect the surface, the function will
+ * return SDL_FALSE and blits will be completely clipped.  Otherwise the
+ * function returns SDL_TRUE and blits to the surface will be clipped to
+ * the intersection of the surface area and the clipping rectangle.
+ *
+ * Note that blits are automatically clipped to the edges of the source
+ * and destination surfaces.
+ */
+extern DECLSPEC SDL_bool SDLCALL SDL_SetClipRect(SDL_Surface * surface,
+                                                 const SDL_Rect * rect);
+
+/*
+ * Gets the clipping rectangle for the destination surface in a blit.
+ * 'rect' must be a pointer to a valid rectangle which will be filled
+ * with the correct values.
+ */
+extern DECLSPEC void SDLCALL SDL_GetClipRect(SDL_Surface * surface,
+                                             SDL_Rect * rect);
+
+/*
+ * Creates a new surface of the specified format, and then copies and maps 
+ * the given surface to it so the blit of the converted surface will be as 
+ * fast as possible.  If this function fails, it returns NULL.
+ *
+ * The 'flags' parameter is passed to SDL_CreateRGBSurface() and has those 
+ * semantics.  You can also pass SDL_RLEACCEL in the flags parameter and
+ * SDL will try to RLE accelerate colorkey and alpha blits in the resulting
+ * surface.
+ *
+ * This function is used internally by SDL_DisplayFormat().
+ */
+extern DECLSPEC SDL_Surface *SDLCALL SDL_ConvertSurface
+    (SDL_Surface * src, SDL_PixelFormat * fmt, Uint32 flags);
+
+/*
+ * This function performs a fast fill of the given rectangle with 'color'
+ * The given rectangle is clipped to the destination surface clip area
+ * and the final fill rectangle is saved in the passed in pointer.
+ * If 'dstrect' is NULL, the whole surface will be filled with 'color'
+ * The color should be a pixel of the format used by the surface, and 
+ * can be generated by the SDL_MapRGB() function.
+ * This function returns 0 on success, or -1 on error.
+ */
+extern DECLSPEC int SDLCALL SDL_FillRect
+    (SDL_Surface * dst, SDL_Rect * dstrect, Uint32 color);
+
+/*
+ * This performs a fast blit from the source surface to the destination
+ * surface.  It assumes that the source and destination rectangles are
+ * the same size.  If either 'srcrect' or 'dstrect' are NULL, the entire
+ * surface (src or dst) is copied.  The final blit rectangles are saved
+ * in 'srcrect' and 'dstrect' after all clipping is performed.
+ * If the blit is successful, it returns 0, otherwise it returns -1.
+ *
+ * The blit function should not be called on a locked surface.
+ *
+ * The blit semantics for surfaces with and without alpha and colorkey
+ * are defined as follows:
+ *
+ * RGBA->RGB:
+ *     SDL_SRCALPHA set:
+ * 	alpha-blend (using alpha-channel).
+ * 	SDL_SRCCOLORKEY ignored.
+ *     SDL_SRCALPHA not set:
+ * 	copy RGB.
+ * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
+ * 	RGB values of the source colour key, ignoring alpha in the
+ * 	comparison.
+ * 
+ * RGB->RGBA:
+ *     SDL_SRCALPHA set:
+ * 	alpha-blend (using the source per-surface alpha value);
+ * 	set destination alpha to opaque.
+ *     SDL_SRCALPHA not set:
+ * 	copy RGB, set destination alpha to source per-surface alpha value.
+ *     both:
+ * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
+ * 	source colour key.
+ * 
+ * RGBA->RGBA:
+ *     SDL_SRCALPHA set:
+ * 	alpha-blend (using the source alpha channel) the RGB values;
+ * 	leave destination alpha untouched. [Note: is this correct?]
+ * 	SDL_SRCCOLORKEY ignored.
+ *     SDL_SRCALPHA not set:
+ * 	copy all of RGBA to the destination.
+ * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
+ * 	RGB values of the source colour key, ignoring alpha in the
+ * 	comparison.
+ * 
+ * RGB->RGB: 
+ *     SDL_SRCALPHA set:
+ * 	alpha-blend (using the source per-surface alpha value).
+ *     SDL_SRCALPHA not set:
+ * 	copy RGB.
+ *     both:
+ * 	if SDL_SRCCOLORKEY set, only copy the pixels matching the
+ * 	source colour key.
+ *
+ * If either of the surfaces were in video memory, and the blit returns -2,
+ * the video memory was lost, so it should be reloaded with artwork and 
+ * re-blitted:
+	while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
+		while ( SDL_LockSurface(image) < 0 )
+			Sleep(10);
+		-- Write image pixels to image->pixels --
+		SDL_UnlockSurface(image);
+	}
+ * This happens under DirectX 5.0 when the system switches away from your
+ * fullscreen application.  The lock will also fail until you have access
+ * to the video memory again.
+ */
+/* You should call SDL_BlitSurface() unless you know exactly how SDL
+   blitting works internally and how to use the other blit functions.
+*/
+#define SDL_BlitSurface SDL_UpperBlit
+
+/* This is the public blit function, SDL_BlitSurface(), and it performs
+   rectangle validation and clipping before passing it to SDL_LowerBlit()
+*/
+extern DECLSPEC int SDLCALL SDL_UpperBlit
+    (SDL_Surface * src, SDL_Rect * srcrect,
+     SDL_Surface * dst, SDL_Rect * dstrect);
+/* This is a semi-private blit function and it performs low-level surface
+   blitting only.
+*/
+extern DECLSPEC int SDLCALL SDL_LowerBlit
+    (SDL_Surface * src, SDL_Rect * srcrect,
+     SDL_Surface * dst, SDL_Rect * dstrect);
+
+/**
+ * \fn int SDL_SoftStretch(SDL_Surface * src, SDL_Rect * srcrect, SDL_Surface * dst, SDL_Rect * dstrect)
+ *
+ * \brief Perform a fast, low quality, stretch blit between two surfaces of the same pixel format.
+ *
+ * \note This function uses a static buffer, and is not thread-safe.
+ */
+extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface * src,
+                                            SDL_Rect * srcrect,
+                                            SDL_Surface * dst,
+                                            SDL_Rect * dstrect);
+
+/* Ends C function definitions when using C++ */
+#ifdef __cplusplus
+/* *INDENT-OFF* */
+}
+/* *INDENT-ON* */
+#endif
+#include "close_code.h"
+
+#endif /* _SDL_surface_h */
+
+/* vi: set ts=4 sw=4 expandtab: */