include/SDL_render.h

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2011 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_render.h
 *  
 *  Header file for SDL 2D rendering functions.
 *
 *  This API supports the following features:
 *      * single pixel points
 *      * single pixel lines
 *      * filled rectangles
 *      * texture images
 *
 *  The primitives may be drawn in opaque, blended, or additive modes.
 *
 *  The texture images may be drawn in opaque, blended, or additive modes.
 *  They can have an additional color tint or alpha modulation applied to
 *  them, and may also be stretched with linear interpolation.
 *
 *  This API is designed to accelerate simple 2D operations. You may
 *  want more functionality such as rotation and particle effects and
 *  in that case you should use SDL's OpenGL/Direct3D support or one
 *  of the many good 3D engines.
 */

#ifndef _SDL_render_h
#define _SDL_render_h

#include "SDL_stdinc.h"
#include "SDL_rect.h"
#include "SDL_video.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
extern "C" {
/* *INDENT-ON* */
#endif

/**
 *  \brief Flags used when creating a rendering context
 */
typedef enum
{
    SDL_RENDERER_ACCELERATED = 0x00000001,      /**< The renderer uses hardware 
                                                     acceleration */
    SDL_RENDERER_PRESENTVSYNC = 0x00000002      /**< Present is synchronized 
                                                     with the refresh rate */
} SDL_RendererFlags;

/**
 *  \brief Information on the capabilities of a render driver or context.
 */
typedef struct SDL_RendererInfo
{
    const char *name;           /**< The name of the renderer */
    Uint32 flags;               /**< Supported ::SDL_RendererFlags */
    Uint32 num_texture_formats; /**< The number of available texture formats */
    Uint32 texture_formats[16]; /**< The available texture formats */
    int max_texture_width;      /**< The maximimum texture width */
    int max_texture_height;     /**< The maximimum texture height */
} SDL_RendererInfo;

/**
 *  \brief The access pattern allowed for a texture.
 */
typedef enum
{
    SDL_TEXTUREACCESS_STATIC,    /**< Changes rarely, not lockable */
    SDL_TEXTUREACCESS_STREAMING  /**< Changes frequently, lockable */
} SDL_TextureAccess;

/**
 *  \brief The texture channel modulation used in SDL_RenderCopy().
 */
typedef enum
{
    SDL_TEXTUREMODULATE_NONE = 0x00000000,     /**< No modulation */
    SDL_TEXTUREMODULATE_COLOR = 0x00000001,    /**< srcC = srcC * color */
    SDL_TEXTUREMODULATE_ALPHA = 0x00000002     /**< srcA = srcA * alpha */
} SDL_TextureModulate;

/**
 *  \brief A structure representing rendering state
 */
struct SDL_Renderer;
typedef struct SDL_Renderer SDL_Renderer;

/**
 *  \brief An efficient driver-specific representation of pixel data
 */
struct SDL_Texture;
typedef struct SDL_Texture SDL_Texture;


/* Function prototypes */

/**
 *  \brief Get the number of 2D rendering drivers available for the current 
 *         display.
 *  
 *  A render driver is a set of code that handles rendering and texture
 *  management on a particular display.  Normally there is only one, but
 *  some drivers may have several available with different capabilities.
 *  
 *  \sa SDL_GetRenderDriverInfo()
 *  \sa SDL_CreateRenderer()
 */
extern DECLSPEC int SDLCALL SDL_GetNumRenderDrivers(void);

/**
 *  \brief Get information about a specific 2D rendering driver for the current 
 *         display.
 *  
 *  \param index The index of the driver to query information about.
 *  \param info  A pointer to an SDL_RendererInfo struct to be filled with 
 *               information on the rendering driver.
 *  
 *  \return 0 on success, -1 if the index was out of range.
 *  
 *  \sa SDL_CreateRenderer()
 */
extern DECLSPEC int SDLCALL SDL_GetRenderDriverInfo(int index,
                                                    SDL_RendererInfo * info);

/**
 *  \brief Create a 2D rendering context for a window.
 *  
 *  \param window The window where rendering is displayed.
 *  \param index    The index of the rendering driver to initialize, or -1 to 
 *                  initialize the first one supporting the requested flags.
 *  \param flags    ::SDL_RendererFlags.
 *  
 *  \return A valid rendering context or NULL if there was an error.
 *  
 *  \sa SDL_CreateSoftwareRenderer()
 *  \sa SDL_GetRendererInfo()
 *  \sa SDL_DestroyRenderer()
 */
extern DECLSPEC SDL_Renderer * SDLCALL SDL_CreateRenderer(SDL_Window * window,
                                               int index, Uint32 flags);

/**
 *  \brief Create a 2D software rendering context for a surface.
 *  
 *  \param surface The surface where rendering is done.
 *  
 *  \return A valid rendering context or NULL if there was an error.
 *  
 *  \sa SDL_CreateRenderer()
 *  \sa SDL_DestroyRenderer()
 */
extern DECLSPEC SDL_Renderer * SDLCALL SDL_CreateSoftwareRenderer(SDL_Surface * surface);

/**
 *  \brief Get information about a rendering context.
 */
extern DECLSPEC int SDLCALL SDL_GetRendererInfo(SDL_Renderer * renderer,
                                                SDL_RendererInfo * info);

/**
 *  \brief Create a texture for a rendering context.
 *  
 *  \param format The format of the texture.
 *  \param access One of the enumerated values in ::SDL_TextureAccess.
 *  \param w      The width of the texture in pixels.
 *  \param h      The height of the texture in pixels.
 *  
 *  \return The created texture is returned, or 0 if no rendering context was 
 *          active,  the format was unsupported, or the width or height were out
 *          of range.
 *  
 *  \sa SDL_QueryTexture()
 *  \sa SDL_UpdateTexture()
 *  \sa SDL_DestroyTexture()
 */
extern DECLSPEC SDL_Texture * SDLCALL SDL_CreateTexture(SDL_Renderer * renderer,                                                        Uint32 format,
                                                        int access, int w,
                                                        int h);

/**
 *  \brief Create a texture from an existing surface.
 *  
 *  \param surface The surface containing pixel data used to fill the texture.
 *  
 *  \return The created texture is returned, or 0 on error.
 *  
 *  \note The surface is not modified or freed by this function.
 *  
 *  \sa SDL_QueryTexture()
 *  \sa SDL_DestroyTexture()
 */
extern DECLSPEC SDL_Texture * SDLCALL SDL_CreateTextureFromSurface(SDL_Renderer * renderer, SDL_Surface * surface);

/**
 *  \brief Query the attributes of a texture
 *  
 *  \param texture A texture to be queried.
 *  \param format  A pointer filled in with the raw format of the texture.  The 
 *                 actual format may differ, but pixel transfers will use this 
 *                 format.
 *  \param access  A pointer filled in with the actual access to the texture.
 *  \param w       A pointer filled in with the width of the texture in pixels.
 *  \param h       A pointer filled in with the height of the texture in pixels.
 *  
 *  \return 0 on success, or -1 if the texture is not valid.
 */
extern DECLSPEC int SDLCALL SDL_QueryTexture(SDL_Texture * texture,
                                             Uint32 * format, int *access,
                                             int *w, int *h);

/**
 *  \brief Set an additional color value used in render copy operations.
 *  
 *  \param texture The texture to update.
 *  \param r       The red color value multiplied into copy operations.
 *  \param g       The green color value multiplied into copy operations.
 *  \param b       The blue color value multiplied into copy operations.
 *  
 *  \return 0 on success, or -1 if the texture is not valid or color modulation 
 *          is not supported.
 *  
 *  \sa SDL_GetTextureColorMod()
 */
extern DECLSPEC int SDLCALL SDL_SetTextureColorMod(SDL_Texture * texture,
                                                   Uint8 r, Uint8 g, Uint8 b);


/**
 *  \brief Get the additional color value used in render copy operations.
 *  
 *  \param texture The texture to query.
 *  \param r         A pointer filled in with the current red color value.
 *  \param g         A pointer filled in with the current green color value.
 *  \param b         A pointer filled in with the current blue color value.
 *  
 *  \return 0 on success, or -1 if the texture is not valid.
 *  
 *  \sa SDL_SetTextureColorMod()
 */
extern DECLSPEC int SDLCALL SDL_GetTextureColorMod(SDL_Texture * texture,
                                                   Uint8 * r, Uint8 * g,
                                                   Uint8 * b);

/**
 *  \brief Set an additional alpha value used in render copy operations.
 *  
 *  \param texture The texture to update.
 *  \param alpha     The alpha value multiplied into copy operations.
 *  
 *  \return 0 on success, or -1 if the texture is not valid or alpha modulation 
 *          is not supported.
 *  
 *  \sa SDL_GetTextureAlphaMod()
 */
extern DECLSPEC int SDLCALL SDL_SetTextureAlphaMod(SDL_Texture * texture,
                                                   Uint8 alpha);

/**
 *  \brief Get the additional alpha value used in render copy operations.
 *  
 *  \param texture The texture to query.
 *  \param alpha     A pointer filled in with the current alpha value.
 *  
 *  \return 0 on success, or -1 if the texture is not valid.
 *  
 *  \sa SDL_SetTextureAlphaMod()
 */
extern DECLSPEC int SDLCALL SDL_GetTextureAlphaMod(SDL_Texture * texture,
                                                   Uint8 * alpha);

/**
 *  \brief Set the blend mode used for texture copy operations.
 *  
 *  \param texture The texture to update.
 *  \param blendMode ::SDL_BlendMode to use for texture blending.
 *  
 *  \return 0 on success, or -1 if the texture is not valid or the blend mode is
 *          not supported.
 *  
 *  \note If the blend mode is not supported, the closest supported mode is
 *        chosen.
 *  
 *  \sa SDL_GetTextureBlendMode()
 */
extern DECLSPEC int SDLCALL SDL_SetTextureBlendMode(SDL_Texture * texture,
                                                    SDL_BlendMode blendMode);

/**
 *  \brief Get the blend mode used for texture copy operations.
 *  
 *  \param texture   The texture to query.
 *  \param blendMode A pointer filled in with the current blend mode.
 *  
 *  \return 0 on success, or -1 if the texture is not valid.
 *  
 *  \sa SDL_SetTextureBlendMode()
 */
extern DECLSPEC int SDLCALL SDL_GetTextureBlendMode(SDL_Texture * texture,
                                                    SDL_BlendMode *blendMode);

/**
 *  \brief Update the given texture rectangle with new pixel data.
 *  
 *  \param texture   The texture to update
 *  \param rect      A pointer to the rectangle of pixels to update, or NULL to 
 *                   update the entire texture.
 *  \param pixels    The raw pixel data.
 *  \param pitch     The number of bytes between rows of pixel data.
 *  
 *  \return 0 on success, or -1 if the texture is not valid.
 *  
 *  \note This is a fairly slow function.
 */
extern DECLSPEC int SDLCALL SDL_UpdateTexture(SDL_Texture * texture,
                                              const SDL_Rect * rect,
                                              const void *pixels, int pitch);

/**
 *  \brief Lock a portion of the texture for pixel access.
 *  
 *  \param texture   The texture to lock for access, which was created with 
 *                   ::SDL_TEXTUREACCESS_STREAMING.
 *  \param rect      A pointer to the rectangle to lock for access. If the rect 
 *                   is NULL, the entire texture will be locked.
 *  \param pixels    This is filled in with a pointer to the locked pixels, 
 *                   appropriately offset by the locked area.
 *  \param pitch     This is filled in with the pitch of the locked pixels.
 *  
 *  \return 0 on success, or -1 if the texture is not valid or was not created with ::SDL_TEXTUREACCESS_STREAMING.
 *  
 *  \sa SDL_UnlockTexture()
 */
extern DECLSPEC int SDLCALL SDL_LockTexture(SDL_Texture * texture,
                                            const SDL_Rect * rect,
                                            void **pixels, int *pitch);

/**
 *  \brief Unlock a texture, uploading the changes to video memory, if needed.
 *  
 *  \sa SDL_LockTexture()
 */
extern DECLSPEC void SDLCALL SDL_UnlockTexture(SDL_Texture * texture);

/**
 *  \brief Set the clipping rectangle for rendering on the current target
 *
 *  \param rect The rectangle to clip rendering to, or NULL to disable clipping.
 *
 *  The contents of the window are not defined after calling
 *  SDL_RenderPresent(), so you should clear the clip rectangle and draw
 *  over the entire window each frame.
 */
extern DECLSPEC void SDLCALL SDL_RenderSetClipRect(SDL_Renderer * renderer,
                                                   const SDL_Rect * rect);

/**
 *  \brief Set the color used for drawing operations (Fill and Line).
 *  
 *  \param r The red value used to draw on the rendering target.
 *  \param g The green value used to draw on the rendering target.
 *  \param b The blue value used to draw on the rendering target.
 *  \param a The alpha value used to draw on the rendering target, usually 
 *           ::SDL_ALPHA_OPAQUE (255).
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDL_SetRenderDrawColor(SDL_Renderer * renderer,
                                           Uint8 r, Uint8 g, Uint8 b,
                                           Uint8 a);

/**
 *  \brief Get the color used for drawing operations (Fill and Line).
 *  
 *  \param r A pointer to the red value used to draw on the rendering target.
 *  \param g A pointer to the green value used to draw on the rendering target.
 *  \param b A pointer to the blue value used to draw on the rendering target.
 *  \param a A pointer to the alpha value used to draw on the rendering target, 
 *           usually ::SDL_ALPHA_OPAQUE (255).
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDL_GetRenderDrawColor(SDL_Renderer * renderer,
                                           Uint8 * r, Uint8 * g, Uint8 * b,
                                           Uint8 * a);

/**
 *  \brief Set the blend mode used for drawing operations (Fill and Line).
 *  
 *  \param blendMode ::SDL_BlendMode to use for blending.
 *  
 *  \return 0 on success, or -1 on error
 *  
 *  \note If the blend mode is not supported, the closest supported mode is 
 *        chosen.
 *  
 *  \sa SDL_GetRenderDrawBlendMode()
 */
extern DECLSPEC int SDLCALL SDL_SetRenderDrawBlendMode(SDL_Renderer * renderer,
                                                       SDL_BlendMode blendMode);

/**
 *  \brief Get the blend mode used for drawing operations.
 *  
 *  \param blendMode A pointer filled in with the current blend mode.
 *  
 *  \return 0 on success, or -1 on error
 *  
 *  \sa SDL_SetRenderDrawBlendMode()
 */
extern DECLSPEC int SDLCALL SDL_GetRenderDrawBlendMode(SDL_Renderer * renderer,
                                                       SDL_BlendMode *blendMode);

/**
 *  \brief Clear the current rendering target with the drawing color
 */
extern DECLSPEC int SDLCALL SDL_RenderClear(SDL_Renderer * renderer);

/**
 *  \brief Draw a point on the current rendering target.
 *  
 *  \param x The x coordinate of the point.
 *  \param y The y coordinate of the point.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderDrawPoint(SDL_Renderer * renderer,
                                                int x, int y);

/**
 *  \brief Draw multiple points on the current rendering target.
 *  
 *  \param points The points to draw
 *  \param count The number of points to draw
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderDrawPoints(SDL_Renderer * renderer,
                                                 const SDL_Point * points,
                                                 int count);

/**
 *  \brief Draw a line on the current rendering target.
 *  
 *  \param x1 The x coordinate of the start point.
 *  \param y1 The y coordinate of the start point.
 *  \param x2 The x coordinate of the end point.
 *  \param y2 The y coordinate of the end point.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderDrawLine(SDL_Renderer * renderer,
                                               int x1, int y1, int x2, int y2);

/**
 *  \brief Draw a series of connected lines on the current rendering target.
 *  
 *  \param points The points along the lines
 *  \param count The number of points, drawing count-1 lines
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderDrawLines(SDL_Renderer * renderer,
                                                const SDL_Point * points,
                                                int count);

/**
 *  \brief Draw a rectangle on the current rendering target.
 *  
 *  \param rect A pointer to the destination rectangle, or NULL to outline the entire rendering target.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderDrawRect(SDL_Renderer * renderer,
                                               const SDL_Rect * rect);

/**
 *  \brief Draw some number of rectangles on the current rendering target.
 *  
 *  \param rects A pointer to an array of destination rectangles.
 *  \param count The number of rectangles.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderDrawRects(SDL_Renderer * renderer,
                                                const SDL_Rect ** rects,
                                                int count);

/**
 *  \brief Fill a rectangle on the current rendering target with the drawing color.
 *  
 *  \param rect A pointer to the destination rectangle, or NULL for the entire 
 *              rendering target.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderFillRect(SDL_Renderer * renderer,
                                               const SDL_Rect * rect);

/**
 *  \brief Fill some number of rectangles on the current rendering target with the drawing color.
 *  
 *  \param rects A pointer to an array of destination rectangles.
 *  \param count The number of rectangles.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderFillRects(SDL_Renderer * renderer,
                                                const SDL_Rect ** rect,
                                                int count);

/**
 *  \brief Copy a portion of the texture to the current rendering target.
 *  
 *  \param texture The source texture.
 *  \param srcrect   A pointer to the source rectangle, or NULL for the entire 
 *                   texture.
 *  \param dstrect   A pointer to the destination rectangle, or NULL for the 
 *                   entire rendering target.
 *  
 *  \return 0 on success, or -1 on error
 */
extern DECLSPEC int SDLCALL SDL_RenderCopy(SDL_Renderer * renderer,
                                           SDL_Texture * texture,
                                           const SDL_Rect * srcrect,
                                           const SDL_Rect * dstrect);

/**
 *  \brief Read pixels from the current rendering target.
 *  
 *  \param rect   A pointer to the rectangle to read, or NULL for the entire 
 *                render target.
 *  \param format The desired format of the pixel data, or 0 to use the format
 *                of the rendering target
 *  \param pixels A pointer to be filled in with the pixel data
 *  \param pitch  The pitch of the pixels parameter.
 *  
 *  \return 0 on success, or -1 if pixel reading is not supported.
 *  
 *  \warning This is a very slow operation, and should not be used frequently.
 */
extern DECLSPEC int SDLCALL SDL_RenderReadPixels(SDL_Renderer * renderer,
                                                 const SDL_Rect * rect,
                                                 Uint32 format,
                                                 void *pixels, int pitch);

/**
 *  \brief Update the screen with rendering performed.
 */
extern DECLSPEC void SDLCALL SDL_RenderPresent(SDL_Renderer * renderer);

/**
 *  \brief Destroy the specified texture.
 *  
 *  \sa SDL_CreateTexture()
 *  \sa SDL_CreateTextureFromSurface()
 */
extern DECLSPEC void SDLCALL SDL_DestroyTexture(SDL_Texture * texture);

/**
 *  \brief Destroy the rendering context for a window and free associated
 *         textures.
 *  
 *  \sa SDL_CreateRenderer()
 */
extern DECLSPEC void SDLCALL SDL_DestroyRenderer(SDL_Renderer * renderer);


/* Ends C function definitions when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */
}
/* *INDENT-ON* */
#endif
#include "close_code.h"

#endif /* _SDL_render_h */

/* vi: set ts=4 sw=4 expandtab: */