GraphicsDisplay.h

00001 /* mbed GraphicsDisplay Display Library Base Class
00002  * Copyright (c) 2007-2009 sford
00003  * Released under the MIT License: http://mbed.org/license/mit
00004  *
00005  * A library for providing a common base class for Graphics displays
00006  * To port a new display, derive from this class and implement
00007  * the constructor (setup the display), pixel (put a pixel
00008  * at a location), width and height functions. Everything else
00009  * (locate, printf, putc, cls, window, putp, fill, blit, blitbit) 
00010  * will come for free. You can also provide a specialised implementation
00011  * of window and putp to speed up the results
00012  */
00013 
00014 #ifndef MBED_GRAPHICSDISPLAY_H
00015 #define MBED_GRAPHICSDISPLAY_H
00016 #include "Bitmap.h"
00017 #include "TextDisplay.h"
00018 
00019 // GraphicsDisplay has one "soft font" which is in a different format
00020 // then the primary font rendering api - see set_font(...). This is
00021 // therefore deprecated, but preserved for a time for backward 
00022 // compatibility.
00023 // #define LOCALFONT
00024 
00025 
00026 /// The GraphicsDisplay class 
00027 /// 
00028 /// This graphics display class supports both graphics and text operations.
00029 /// Typically, a subclass is derived from this which has localizations to
00030 /// adapt to a specific hardware platform (e.g. a display controller chip),
00031 /// that overrides methods in here to either add more capability or perhaps 
00032 /// to improve performance, by leveraging specific hardware capabilities.
00033 ///
00034 class GraphicsDisplay : public TextDisplay 
00035 {
00036 public:
00037     /// The constructor
00038     GraphicsDisplay(const char* name);
00039     
00040     /// Draw a pixel in the specified color.
00041     ///
00042     /// @note this method must be supported in the derived class.
00043     ///
00044     /// @param x is the horizontal offset to this pixel.
00045     /// @param y is the vertical offset to this pixel.
00046     /// @param color defines the color for the pixel.
00047     /// @returns success/failure code. @see RetCode_t.
00048     ///
00049     virtual RetCode_t pixel(loc_t x, loc_t y, color_t color) = 0;
00050     
00051     /// Write a stream of pixels to the display.
00052     ///
00053     /// @note this method must be supported in the derived class.
00054     ///
00055     /// @param p is a pointer to a color_t array to write.
00056     /// @param count is the number of pixels to write.
00057     /// @param x is the horizontal position on the display.
00058     /// @param y is the vertical position on the display.
00059     /// @returns success/failure code. @see RetCode_t.
00060     ///
00061     virtual RetCode_t pixelStream(color_t * p, uint32_t count, loc_t x, loc_t y) = 0;
00062 
00063     /// Get a pixel from the display.
00064     ///
00065     /// @note this method must be supported in the derived class.
00066     ///
00067     /// @param x is the horizontal offset to this pixel.
00068     /// @param y is the vertical offset to this pixel.
00069     /// @returns the pixel. see @color_t
00070     ///
00071     virtual color_t getPixel(loc_t x, loc_t y) = 0;
00072 
00073     /// Get a stream of pixels from the display.
00074     ///
00075     /// @note this method must be supported in the derived class.
00076     ///
00077     /// @param p is a pointer to a color_t array to accept the stream.
00078     /// @param count is the number of pixels to read.
00079     /// @param x is the horizontal offset to this pixel.
00080     /// @param y is the vertical offset to this pixel.
00081     /// @returns success/failure code. @see RetCode_t.
00082     ///
00083     virtual RetCode_t getPixelStream(color_t * p, uint32_t count, loc_t x, loc_t y) = 0;
00084     
00085     /// get the screen width in pixels
00086     ///
00087     /// @note this method must be supported in the derived class.
00088     ///
00089     /// @returns screen width in pixels.
00090     ///
00091     virtual uint16_t width() = 0;
00092     
00093     /// get the screen height in pixels
00094     ///
00095     /// @note this method must be supported in the derived class.
00096     ///
00097     /// @returns screen height in pixels.
00098     ///
00099     virtual uint16_t height() = 0;
00100 
00101     /// Prepare the controller to write binary data to the screen by positioning
00102     /// the memory cursor.
00103     ///
00104     /// @note this method must be supported in the derived class.
00105     ///
00106     /// @param x is the horizontal position in pixels (from the left edge)
00107     /// @param y is the vertical position in pixels (from the top edge)
00108     /// @returns success/failure code. @see RetCode_t.
00109     ///
00110     virtual RetCode_t SetGraphicsCursor(loc_t x, loc_t y) = 0;
00111     
00112     /// Prepare the controller to read binary data from the screen by positioning
00113     /// the memory read cursor.
00114     ///
00115     /// @param x is the horizontal position in pixels (from the left edge)
00116     /// @param y is the vertical position in pixels (from the top edge)
00117     /// @returns success/failure code. @see RetCode_t.
00118     ///
00119     virtual RetCode_t SetGraphicsCursorRead(loc_t x, loc_t y) = 0;
00120     
00121     /// Draw a filled rectangle in the specified color
00122     ///
00123     /// @note As a side effect, this changes the current
00124     ///     foreground color for subsequent operations.
00125     ///
00126     /// @note this method must be supported in the derived class.
00127     ///
00128     /// @param x1 is the horizontal start of the line.
00129     /// @param y1 is the vertical start of the line.
00130     /// @param x2 is the horizontal end of the line.
00131     /// @param y2 is the vertical end of the line.
00132     /// @param color defines the foreground color.
00133     /// @param fillit is optional to NOFILL the rectangle. default is FILL.
00134     /// @returns success/failure code. @see RetCode_t.
00135     ///
00136     virtual RetCode_t fillrect(loc_t x1, loc_t y1, loc_t x2, loc_t y2, 
00137         color_t color, fill_t fillit = FILL) = 0;
00138 
00139 
00140     virtual RetCode_t WriteCommand(unsigned char command, unsigned int data = 0xFFFF) = 0;
00141     virtual RetCode_t WriteData(unsigned char data) = 0;
00142 
00143     /// Set the window, which controls where items are written to the screen.
00144     ///
00145     /// When something hits the window width, it wraps back to the left side
00146     /// and down a row. If the initial write is outside the window, it will
00147     /// be captured into the window when it crosses a boundary.
00148     ///
00149     /// @param x is the left edge in pixels.
00150     /// @param y is the top edge in pixels.
00151     /// @param w is the window width in pixels.
00152     /// @param h is the window height in pixels.
00153     /// @returns success/failure code. @see RetCode_t.
00154     ///
00155     virtual RetCode_t window(loc_t x, loc_t y, dim_t w, dim_t h);
00156     
00157     /// Clear the screen.
00158     ///
00159     /// The behavior is to clear the whole screen.
00160     ///
00161     /// @returns success/failure code. @see RetCode_t.
00162     ///
00163     virtual RetCode_t cls();
00164     
00165 
00166     virtual void WindowMax(void);
00167     
00168     /// method to put a single color pixel to the screen.
00169     ///
00170     /// This method may be called as many times as necessary after 
00171     /// @see _StartGraphicsStream() is called, and it should be followed 
00172     /// by _EndGraphicsStream.
00173     ///
00174     /// @param pixel is a color value to be put on the screen.
00175     /// @returns error code.
00176     ///
00177     virtual RetCode_t putp(color_t pixel);
00178 
00179             
00180     virtual void fill(int x, int y, int w, int h, color_t color);
00181     virtual void blit(int x, int y, int w, int h, const int * color);    
00182     
00183     /// This method transfers one character from the external font data
00184     /// to the screen.
00185     ///
00186     /// @note the font data is in a special format as generate by
00187     ///         the mikroe font creator. \\
00188     ///         See http://www.mikroe.com/glcd-font-creator/
00189     ///
00190     /// @param x is the horizontal pixel coordinate
00191     /// @param y is the vertical pixel coordinate
00192     /// @param fontTable is the base of the table which has the metrics
00193     /// @param fontChar is the start of that record in the table for the char (e.g. 'A' - 'Z')
00194     /// @returns how far the cursor should advance to the right in pixels
00195     ///
00196     virtual int fontblit(int x, int y, const unsigned char * fontTable, const unsigned char * fontChar);
00197     
00198     /// This method returns the color value from a palette.
00199     ///
00200     /// This method accepts a pointer to a Bitmap color palette, which
00201     /// is a table in memory composed of RGB Quad values (r, g, b, 0),
00202     /// and an index into that table. It then extracts the color information
00203     /// and downsamples it to a color_t value which it returns.
00204     ///
00205     /// @note This method probably has very little value outside of
00206     ///         the internal methods for reading BMP files.
00207     ///
00208     /// @param colorPalette is the handle to the color palette to use.
00209     /// @param i is the index into the color palette.
00210     /// @returns the color in color_t format.
00211     ///
00212     color_t RGBQuadToRGB16(RGBQUAD * colorPalette, uint16_t i);
00213     
00214     /// This method converts a 16-bit color value into a 24-bit RGB Quad.
00215     ///
00216     /// @param c is the 16-bit color. @see color_t
00217     /// @returns an RGBQUAD value. @see RGBQUAD
00218     ///
00219     RGBQUAD RGB16ToRGBQuad(color_t c);
00220 
00221     /// This method attempts to render a specified graphics image file at
00222     /// the specified screen location.
00223     ///
00224     /// This supports several variants of the following file types:
00225     /// \li Bitmap file format,
00226     /// \li Icon file format.
00227     ///
00228     /// @note The specified image width and height, when adjusted for the 
00229     ///     x and y origin, must fit on the screen, or the image will not
00230     ///     be shown (it does not clip the image).
00231     ///
00232     /// @note The file extension is tested, and if it ends in a supported
00233     ///     format, the appropriate handler is called to render that image.
00234     ///
00235     /// @param x is the horizontal pixel coordinate
00236     /// @param y is the vertical pixel coordinate
00237     /// @param FileName refers to the fully qualified path and file on 
00238     ///     a mounted file system.
00239     /// @returns success or error code.
00240     ///
00241     RetCode_t RenderImageFile(loc_t x, loc_t y, const char *FileName);
00242 
00243     /// This method reads a disk file that is in bitmap format and 
00244     /// puts it on the screen.
00245     ///
00246     /// Supported formats:
00247     /// \li 4-bit color format (16 colors)
00248     /// \li 8-bit color format (256 colors)
00249     /// \li 16-bit color format (65k colors)
00250     /// \li compression: no.
00251     ///
00252     /// @note This is a slow operation, typically due to the use of
00253     ///         the file system, and partially because bmp files
00254     ///         are stored from the bottom up, and the memory is written
00255     ///         from the top down; as a result, it constantly 'seeks'
00256     ///         on the file system for the next row of information.
00257     ///
00258     /// As a performance test, a sample picture was timed. A family picture
00259     /// was converted to Bitmap format; shrunk to 352 x 272 pixels and save
00260     /// in 8-bit color format. The resulting file size was 94.5 KByte.
00261     /// The SPI port interface was set to 20 MHz.
00262     /// The original bitmap rendering software was purely in software, 
00263     /// pushing 1 pixel at a time to the write function, which did use SPI
00264     /// hardware (not pin wiggling) to transfer commands and data to the 
00265     /// display. Then, the driver was improved to leverage the capability
00266     /// of the derived display driver. As a final check, instead of the
00267     /// [known slow] local file system, a randomly chosen USB stick was 
00268     /// used. The performance results are impressive (but depend on the
00269     /// listed factors). 
00270     ///
00271     /// \li 34 seconds, LocalFileSystem, Software Rendering
00272     /// \li 9 seconds, LocalFileSystem, Hardware Rending for RA8875
00273     /// \li 3 seconds, MSCFileSystem, Hardware Rendering for RA8875
00274     /// 
00275     /// @param x is the horizontal pixel coordinate
00276     /// @param y is the vertical pixel coordinate
00277     /// @param Name_BMP is the filename on the mounted file system.
00278     /// @returns success or error code.
00279     ///
00280     RetCode_t RenderBitmapFile(loc_t x, loc_t y, const char *Name_BMP);
00281     
00282     
00283     /// This method reads a disk file that is in ico format and 
00284     /// puts it on the screen.
00285     ///
00286     /// Reading the disk is slow, but a typical icon file is small
00287     /// so it should be ok.
00288     ///
00289     /// @note An Icon file can have more than one icon in it. This
00290     ///     implementation only processes the first image in the file.
00291     ///
00292     /// @param x is the horizontal pixel coordinate
00293     /// @param y is the vertical pixel coordinate
00294     /// @param Name_ICO is the filename on the mounted file system.
00295     /// @returns success or error code.
00296     ///
00297     RetCode_t RenderIconFile(loc_t x, loc_t y, const char *Name_ICO);
00298 
00299     
00300     /// This method captures the specified area as a 24-bit bitmap file.
00301     ///
00302     /// Even though this is a 16-bit display, the stored image is in
00303     /// 24-bit format.
00304     ///
00305     /// @param x is the left edge of the region to capture
00306     /// @param y is the top edge of the region to capture
00307     /// @param w is the width of the region to capture
00308     /// @param h is the height of the region to capture.
00309     /// @return success or error code.
00310     ///
00311     RetCode_t PrintScreen(loc_t x, loc_t y, dim_t w, dim_t h, const char *Name_BMP);
00312     
00313     /// prints one character at the specified coordinates.
00314     ///
00315     /// This will print the character at the specified pixel coordinates.
00316     ///
00317     /// @param x is the horizontal offset in pixels.
00318     /// @param y is the vertical offset in pixels.
00319     /// @param value is the character to print.
00320     /// @returns number of pixels to index to the right if a character was printed, 0 otherwise.
00321     ///
00322     virtual int character(int x, int y, int value);
00323     
00324     /// get the number of colums based on the currently active font
00325     ///
00326     /// @returns number of columns.
00327     ///    
00328     virtual int columns(void);
00329 
00330     /// get the number of rows based on the currently active font
00331     ///
00332     /// @returns number of rows.
00333     ///    
00334     virtual int rows(void);
00335     
00336     /// Select a bitmap font (provided by the user) for all subsequent text
00337     /// rendering.
00338     ///
00339     /// This API permits selection of a special memory mapped font, which 
00340     /// enables the presentation of many font sizes and styles, including
00341     /// proportional fonts.
00342     ///
00343     /// @note Tool to create the fonts is accessible from its creator
00344     ///     available at http://www.mikroe.com.
00345     ///     Hint: Change the data to an array of type char[].
00346     ///
00347     ///     This special font array has a 4-byte header, followed by 
00348     ///     the data:
00349     ///   \li the number of bytes per char
00350     ///   \li the vertical size in pixels for each character
00351     ///   \li the horizontal size in pixels for each character
00352     ///   \li the number of bytes per vertical line (width of the array)
00353     ///   \li the subsequent records are the font information.
00354     ///
00355     /// @param font is a pointer to a specially formed font array. 
00356     ///     NULL, or the omission of this parameter will restore the default
00357     ///     font capability, which may use the display controllers hardware
00358     ///     font (if available), or no font.
00359     /// @returns error code.
00360     ///
00361     virtual RetCode_t set_font(const unsigned char * font = NULL);
00362 
00363 protected:
00364 
00365     /// Pure virtual method indicating the start of a graphics stream.
00366     ///
00367     /// This is called prior to a stream of pixel data being sent.
00368     /// This may cause register configuration changes in the derived
00369     /// class in order to prepare the hardware to accept the streaming
00370     /// data.
00371     ///
00372     /// @note this method must be supported in the derived class.
00373     ///
00374     /// @returns error code.
00375     ///
00376     virtual RetCode_t _StartGraphicsStream(void) = 0;
00377     
00378     /// Pure virtual method indicating the end of a graphics stream.
00379     ///
00380     /// This is called to conclude a stream of pixel data that was sent.
00381     /// This may cause register configuration changes in the derived
00382     /// class in order to stop the hardware from accept the streaming
00383     /// data.
00384     ///
00385     /// @note this method must be supported in the derived class.
00386     ///
00387     /// @returns error code.
00388     ///
00389     virtual RetCode_t _EndGraphicsStream(void) = 0;
00390 
00391     /// Protected method to render an image given a file handle and 
00392     /// coordinates.
00393     ///
00394     /// @param x is the horizontal pixel coordinate
00395     /// @param y is the vertical pixel coordinate
00396     /// @param w is the image width restriction, or zero to permit full image width.
00397     /// @param h is the image height restriction, or zero to permit full image height.
00398     /// @param fileOffset is the offset into the file where the image data starts
00399     /// @param Image is the filename stream already opened for the data.
00400     /// @returns success or error code.
00401     ///
00402     RetCode_t _RenderBitmap(loc_t x, loc_t y, uint32_t fileOffset, FILE * Image);
00403 
00404     #ifdef LOCALFONT
00405     virtual int blitbit(int x, int y, int w, int h, const char * color);
00406     #endif
00407     
00408     const unsigned char * font;     ///< reference to an external font somewhere in memory
00409     
00410     // pixel location
00411     short _x;
00412     short _y;
00413     
00414     // window location
00415     short _x1;
00416     short _x2;
00417     short _y1;
00418     short _y2;
00419 };
00420 
00421 #endif
00422