don't allocate backbuffer for dummy surfaces

[wxWidgets.git] / include / wx / gifdecod.h

diff --git a/include/wx/gifdecod.h b/include/wx/gifdecod.h
index 3d4fb9bc0eb489c5160c9016cde6395f2e585994..cb9490e8922f6e6b3f1ee87526591b621484a048 100644 (file)
--- a/include/wx/gifdecod.h
+++ b/include/wx/gifdecod.h
@@ -11,11 +11,7 @@
 #ifndef _WX_GIFDECOD_H
 #define _WX_GIFDECOD_H
 
-#ifdef __GNUG__
-#pragma interface "gifdecod.h"
-#endif
-
-#include "wx/setup.h"
+#include "wx/defs.h"
 
 #if wxUSE_STREAMS && wxUSE_GIF
 
@@ -23,8 +19,50 @@
 #include "wx/image.h"
 
 
-typedef struct _IMAGEN
+// --------------------------------------------------------------------------
+// Constants
+// --------------------------------------------------------------------------
+
+// Error codes:
+//  Note that the error code wxGIF_TRUNCATED means that the image itself
+//  is most probably OK, but the decoder didn't reach the end of the data
+//  stream; this means that if it was not reading directly from file,
+//  the stream will not be correctly positioned. the
+//
+enum
+{
+    wxGIF_OK = 0,                   /* everything was OK */
+    wxGIF_INVFORMAT,                /* error in gif header */
+    wxGIF_MEMERR,                   /* error allocating memory */
+    wxGIF_TRUNCATED                 /* file appears to be truncated */
+};
+
+// Disposal method
+//  Experimental; subject to change.
+//
+enum
 {
+    wxGIF_D_UNSPECIFIED = -1,       /* not specified */
+    wxGIF_D_DONOTDISPOSE = 0,       /* do not dispose */
+    wxGIF_D_TOBACKGROUND = 1,       /* restore to background colour */
+    wxGIF_D_TOPREVIOUS = 2          /* restore to previous image */
+};
+
+
+#define MAX_BLOCK_SIZE 256          /* max. block size */
+
+
+// --------------------------------------------------------------------------
+// wxGIFDecoder class
+// --------------------------------------------------------------------------
+
+// internal class for storing GIF image data
+class GIFImage
+{
+public:
+    // def ctor
+    GIFImage();
+
     unsigned int w;                 /* width */
     unsigned int h;                 /* height */
     unsigned int left;              /* x coord (in logical screen) */
@@ -34,68 +72,50 @@ typedef struct _IMAGEN
     long delay;                     /* delay in ms (-1 = unused) */
     unsigned char *p;               /* bitmap */
     unsigned char *pal;             /* palette */
-    struct _IMAGEN *next;           /* next image */
-    struct _IMAGEN *prev;           /* prev image */
-} IMAGEN;
-
+    unsigned int ncolours;          /* number of colours */
+    GIFImage *next;                 /* next image */
+    GIFImage *prev;                 /* prev image */
 
-/* disposal method */
-#define D_UNSPECIFIED   -1          /* not specified */
-#define D_DONOTDISPOSE  0           /* do not dispose */
-#define D_TOBACKGROUND  1           /* restore to background colour */
-#define D_TOPREVIOUS    2           /* restore to previous image */
-
-/* error codes */
-#define E_OK            0           /* everything was OK */
-#define E_FORMATO       1           /* error in gif header */
-#define E_MEMORIA       2           /* error allocating memory */
+    DECLARE_NO_COPY_CLASS(GIFImage)
+};
 
-#define MAX_BLOCK_SIZE  256         /* max. block size */
 
 class WXDLLEXPORT wxGIFDecoder
 {
 private:
-    /* logical screen */
+    // logical screen
     unsigned int  m_screenw;        /* logical screen width */
     unsigned int  m_screenh;        /* logical screen height */
     int           m_background;     /* background color (-1 = none) */
 
-    /* image data */
+    // image data
     bool          m_anim;           /* animated GIF */
     int           m_nimages;        /* number of images */
     int           m_image;          /* current image */
-    IMAGEN        *m_pimage;        /* pointer to current image */
-    IMAGEN        *m_pfirst;        /* pointer to first image */
-    IMAGEN        *m_plast;         /* pointer to last image */
+    GIFImage      *m_pimage;        /* pointer to current image */
+    GIFImage      *m_pfirst;        /* pointer to first image */
+    GIFImage      *m_plast;         /* pointer to last image */
 
-    /* decoder state vars */
+    // decoder state vars
     int           m_restbits;       /* remaining valid bits */
     unsigned int  m_restbyte;       /* remaining bytes in this block */
     unsigned int  m_lastbyte;       /* last byte read */
     unsigned char m_buffer[MAX_BLOCK_SIZE];     /* buffer for reading */
     unsigned char *m_bufp;          /* pointer to next byte in buffer */
 
-    wxInputStream *m_f;             /* input file */
+    // input stream
+    wxInputStream *m_f;             /* input stream */
 
 private:
     int getcode(int bits, int abfin);
-    int dgif(IMAGEN *img, int interl, int bits);
+    int dgif(GIFImage *img, int interl, int bits);
 
 public:
-    // constructor, destructor, etc.
-    wxGIFDecoder(wxInputStream *s, bool anim = FALSE);
-    ~wxGIFDecoder();
-    bool CanRead();
-    int ReadGIF();
-    void Destroy();
-
-    // convert current frame to wxImage
-    bool ConvertToImage(wxImage *image) const;
-
     // get data of current frame
     int GetFrameIndex() const;
     unsigned char* GetData() const;
     unsigned char* GetPalette() const;
+    unsigned int GetNcolours() const;
     unsigned int GetWidth() const;
     unsigned int GetHeight() const;
     unsigned int GetLeft() const;
@@ -114,9 +134,22 @@ public:
     // move through the animation
     bool GoFirstFrame();
     bool GoLastFrame();
-    bool GoNextFrame(bool cyclic = FALSE);
-    bool GoPrevFrame(bool cyclic = FALSE);
+    bool GoNextFrame(bool cyclic = false);
+    bool GoPrevFrame(bool cyclic = false);
     bool GoFrame(int which);
+
+public:
+    // constructor, destructor, etc.
+    wxGIFDecoder(wxInputStream *s, bool anim = false);
+    ~wxGIFDecoder();
+    bool CanRead();
+    int ReadGIF();
+    void Destroy();
+
+    // convert current frame to wxImage
+    bool ConvertToImage(wxImage *image) const;
+
+    DECLARE_NO_COPY_CLASS(wxGIFDecoder)
 };