Add some function declarations of the core native framebuffer managem…

…ent implementation

native/pyframebuffer.h

@@ -3,6 +3,8 @@
 
 #include <linux/fb.h>
 
+#include <stdint.h>
+
 // decorators for marking functions and variables
 
 /**
@@ -16,22 +18,109 @@
 #define __APISTATUS_deprecated
 
 // if GNUC, also add a GNUC attribute for deprecation
-#if defined(__GNUC__)
+#if defined(__GNUC__) && !defined(__DOXYGEN__)
 
 #undef __APISTATUS_deprecated
 #define __APISTATUS_deprecated __attribute__((deprecated("This function is deprecated and will be removed in a future version.")))
 
 #endif
 
+/**
+ * The maximum amount of framebuffers that this library can handle.
+ * Normally as the device file @c /dev/fbXX can have a number between
+ * @c 0-31 , this means that @c 32 framebuffers can be handled, and
+ * these we will also handle here.
+ */
+#define MAX_FRAMEBUFFERS 32
+
 /**
  * Used for storing the videomode information.
  */
-struct pyfb_videmode
-{
+struct pyfb_videomode_info {
     /**
      * The screeninfo from the framebuffer.
      */
     const struct fb_var_screeninfo vinfo;
+
+    /**
+     * The size of the framebuffer in bytes.
+     */
+    const unsigned long int fb_size_b;
+};
+
+/**
+ * Used for store framebuffer information internally.
+ */
+struct pyfb_framebuffer {
+
+    /**
+     * The framebuffer information.
+     */
+    struct pyfb_videomode_info fb_info;
+
+    /**
+     * The offscreen buffer for the framebuffer. The buffer to use of these
+     * in this union depend on the framebuffer depth. To get the framebuffer
+     * depth, use the @c pyfb_videomode_info.vinfo.bits_per_pixel field.
+     */
+    union {
+        /**
+         * Used if the framebuffer depth (color bits) is 8bit.
+         */
+        uint8_t* u8_buffer;
+
+        /**
+         * Used if the framebuffer depth (color bits) is 16bit.
+         */
+        uint16_t* u16_buffer;
+
+        /**
+         * Used if the framebuffer depth (color bits) is 32bit.
+         */
+        uint32_t* u32_buffer;
+    };
 };
 
+/**
+ * Opens a framebuffer. If it is allready opened, the implementation will remember
+ * that the framebuffer is hold by multiple users and will free all resources to
+ * this framebuffer only when the pyfb_close function is called the amount of times
+ * this function has been called to be sure no user is using it.
+ *
+ * @param num The framebuffer number to open, usually a number between 0 and 31
+ *
+ * @return By success 0, else -1
+ */
+extern int pyfb_open(uint8_t num);
+
+/**
+ * Closes a framebuffer. This function does not closes the framebuffer automaticly!
+ * If multiple times the pyfb_open function has been called on the framebuffer to
+ * close, then it will only decrement the amount of users currently using this
+ * framebuffer. Only if no other user is marked using this framebuffer, then all
+ * resources related to the framebuffer will be cleaned up.
+ *
+ * @param num The framebuffer number to close
+ */
+extern void pyfb_close(uint8_t num);
+
+/**
+ * Returns the videomode info of a specific framebuffer. If the framebuffer is not
+ * opened, then the @c pyfb_videomode_info.fb_size_b field will be @c 0 . If it is
+ * not 0, then the structure is valid and the framebuffer is opened.
+ *
+ * @param num The framebuffer number to get the infos of
+ * @param info_ptr The pointer to copy the videmode info to
+ */
+extern void pyfb_vinfo(uint8_t num, struct pyfb_videomode_info* info_ptr);
+
+/**
+ * Checks if the framebuffer number is opened.
+ *
+ * @param num The framebuffer number to check
+ *
+ * @return If opened returns 0, else -1
+ */
+extern int pyfb_isopen(uint8_t num);
+
 #endif