MicroBitImage.h

00001 /*
00002 The MIT License (MIT)
00003 
00004 Copyright (c) 2016 British Broadcasting Corporation.
00005 This software is provided by Lancaster University by arrangement with the BBC.
00006 
00007 Permission is hereby granted, free of charge, to any person obtaining a
00008 copy of this software and associated documentation files (the "Software"),
00009 to deal in the Software without restriction, including without limitation
00010 the rights to use, copy, modify, merge, publish, distribute, sublicense,
00011 and/or sell copies of the Software, and to permit persons to whom the
00012 Software is furnished to do so, subject to the following conditions:
00013 
00014 The above copyright notice and this permission notice shall be included in
00015 all copies or substantial portions of the Software.
00016 
00017 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00018 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00019 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
00020 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00021 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00022 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
00023 DEALINGS IN THE SOFTWARE.
00024 */
00025 
00026 #ifndef MICROBIT_IMAGE_H
00027 #define MICROBIT_IMAGE_H
00028 
00029 #include "mbed.h"
00030 #include "MicroBitConfig.h"
00031 #include "ManagedString.h"
00032 #include "RefCounted.h"
00033 
00034 struct ImageData : RefCounted
00035 {
00036     uint16_t width;     // Width in pixels
00037     uint16_t height;    // Height in pixels
00038     uint8_t data[0];    // 2D array representing the bitmap image
00039 };
00040 
00041 /**
00042   * Class definition for a MicroBitImage.
00043   *
00044   * An MicroBitImage is a simple bitmap representation of an image.
00045   * n.b. This is a mutable, managed type.
00046   */
00047 class MicroBitImage
00048 {
00049     ImageData *ptr;     // Pointer to payload data
00050 
00051 
00052     /**
00053       * Internal constructor which provides sanity checking and initialises class properties.
00054       *
00055       * @param x the width of the image
00056       *
00057       * @param y the height of the image
00058       *
00059       * @param bitmap an array of integers that make up an image.
00060       */
00061     void init(const int16_t x, const int16_t y, const uint8_t *bitmap);
00062 
00063     /**
00064       * Internal constructor which defaults to the Empty Image instance variable
00065       */
00066     void init_empty();
00067 
00068     public:
00069     static MicroBitImage EmptyImage;    // Shared representation of a null image.
00070 
00071     /**
00072       * Get current ptr, do not decr() it, and set the current instance to empty image.
00073       *
00074       * This is to be used by specialized runtimes which pass ImageData around.
00075       */
00076     ImageData *leakData();
00077 
00078     /**
00079       * Return a 2D array representing the bitmap image.
00080       */
00081     uint8_t *getBitmap()
00082     {
00083         return ptr->data;
00084     }
00085 
00086     /**
00087       * Constructor.
00088       * Create an image from a specially prepared constant array, with no copying. Will call ptr->incr().
00089       *
00090       * @param ptr The literal - first two bytes should be 0xff, then width, 0, height, 0, and the bitmap. Width and height are 16 bit. The literal has to be 4-byte aligned.
00091       *
00092       * @code
00093       * static const uint8_t heart[] __attribute__ ((aligned (4))) = { 0xff, 0xff, 10, 0, 5, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00094       * MicroBitImage i((ImageData*)(void*)heart);
00095       * @endcode
00096       */
00097     MicroBitImage(ImageData *ptr);
00098 
00099     /**
00100       * Default Constructor.
00101       * Creates a new reference to the empty MicroBitImage bitmap
00102       *
00103       * @code
00104       * MicroBitImage i(); //an empty image instance
00105       * @endcode
00106       */
00107     MicroBitImage();
00108 
00109 
00110     /**
00111       * Copy Constructor.
00112       * Add ourselves as a reference to an existing MicroBitImage.
00113       *
00114       * @param image The MicroBitImage to reference.
00115       *
00116       * @code
00117       * MicroBitImage i("0,1,0,1,0\n");
00118       * MicroBitImage i2(i); //points to i
00119       * @endcode
00120       */
00121     MicroBitImage(const MicroBitImage &image);
00122 
00123     /**
00124       * Constructor.
00125       * Create a blank bitmap representation of a given size.
00126       *
00127       * @param s A text based representation of the image given whitespace delimited numeric values.
00128       *
00129       * @code
00130       * MicroBitImage i("0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n"); // 5x5 image
00131       * @endcode
00132       */
00133     explicit MicroBitImage(const char *s);
00134 
00135     /**
00136       * Constructor.
00137       * Create a blank bitmap representation of a given size.
00138       *
00139       * @param x the width of the image.
00140       *
00141       * @param y the height of the image.
00142       *
00143       * Bitmap buffer is linear, with 8 bits per pixel, row by row,
00144       * top to bottom with no word alignment. Stride is therefore the image width in pixels.
00145       * in where w and h are width and height respectively, the layout is therefore:
00146       *
00147       * |[0,0]...[w,o][1,0]...[w,1]  ...  [[w,h]
00148       *
00149       * A copy of the image is made in RAM, as images are mutable.
00150       */
00151     MicroBitImage(const int16_t x, const int16_t y);
00152 
00153     /**
00154       * Constructor.
00155       * Create a bitmap representation of a given size, based on a given buffer.
00156       *
00157       * @param x the width of the image.
00158       *
00159       * @param y the height of the image.
00160       *
00161       * @param bitmap a 2D array representing the image.
00162       *
00163       * @code
00164       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00165       * MicroBitImage i(10,5,heart);
00166       * @endcode
00167       */
00168     MicroBitImage(const int16_t x, const int16_t y, const uint8_t *bitmap);
00169 
00170     /**
00171       * Destructor.
00172       *
00173       * Removes buffer resources held by the instance.
00174       */
00175     ~MicroBitImage();
00176 
00177     /**
00178       * Copy assign operation.
00179       *
00180       * Called when one MicroBitImage is assigned the value of another using the '=' operator.
00181       *
00182       * Decrement our reference count and free up the buffer as necessary.
00183       *
00184       * Then, update our buffer to refer to that of the supplied MicroBitImage,
00185       * and increase its reference count.
00186       *
00187       * @param s The MicroBitImage to reference.
00188       *
00189       * @code
00190       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00191       * MicroBitImage i(10,5,heart);
00192       * MicroBitImage i1();
00193       * i1 = i; // i1 now references i
00194       * @endcode
00195       */
00196     MicroBitImage& operator = (const MicroBitImage& i);
00197 
00198 
00199     /**
00200       * Equality operation.
00201       *
00202       * Called when one MicroBitImage is tested to be equal to another using the '==' operator.
00203       *
00204       * @param i The MicroBitImage to test ourselves against.
00205       *
00206       * @return true if this MicroBitImage is identical to the one supplied, false otherwise.
00207       *
00208       * @code
00209       * MicroBitDisplay display;
00210       * MicroBitImage i();
00211       * MicroBitImage i1();
00212       *
00213       * if(i == i1) //will be true
00214       *     display.scroll("true");
00215       * @endcode
00216       */
00217     bool operator== (const MicroBitImage& i);
00218 
00219     /**
00220       * Resets all pixels in this image to 0.
00221       *
00222       * @code
00223       * MicroBitImage i("0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n"); // 5x5 image
00224       * i.clear();
00225       * @endcode
00226       */
00227     void clear();
00228 
00229     /**
00230       * Sets the pixel at the given co-ordinates to a given value.
00231       *
00232       * @param x The co-ordinate of the pixel to change.
00233       *
00234       * @param y The co-ordinate of the pixel to change.
00235       *
00236       * @param value The new value of the pixel (the brightness level 0-255)
00237       *
00238       * @return MICROBIT_OK, or MICROBIT_INVALID_PARAMETER.
00239       *
00240       * @code
00241       * MicroBitImage i("0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n"); // 5x5 image
00242       * i.setPixelValue(0,0,255);
00243       * @endcode
00244       *
00245       * @note all coordinates originate from the top left of an image.
00246       */
00247     int setPixelValue(int16_t x , int16_t y, uint8_t value);
00248 
00249     /**
00250       * Retrieves the value of a given pixel.
00251       *
00252       * @param x The x co-ordinate of the pixel to read. Must be within the dimensions of the image.
00253       *
00254       * @param y The y co-ordinate of the pixel to read. Must be within the dimensions of the image.
00255       *
00256       * @return The value assigned to the given pixel location (the brightness level 0-255), or MICROBIT_INVALID_PARAMETER.
00257       *
00258       * @code
00259       * MicroBitImage i("0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n1,0,1,0,1\n0,1,0,1,0\n"); // 5x5 image
00260       * i.getPixelValue(0,0); //should be 0;
00261       * @endcode
00262       */
00263     int getPixelValue(int16_t x , int16_t y);
00264 
00265     /**
00266       * Replaces the content of this image with that of a given 2D array representing
00267       * the image.
00268       *
00269       * @param x the width of the image. Must be within the dimensions of the image.
00270       *
00271       * @param y the width of the image. Must be within the dimensions of the image.
00272       *
00273       * @param bitmap a 2D array representing the image.
00274       *
00275       * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER.
00276       *
00277       * @code
00278       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00279       * MicroBitImage i();
00280       * i.printImage(0,0,heart);
00281       * @endcode
00282       *
00283       * @note all coordinates originate from the top left of an image.
00284       */
00285     int printImage(int16_t x, int16_t y, const uint8_t *bitmap);
00286 
00287     /**
00288       * Pastes a given bitmap at the given co-ordinates.
00289       *
00290       * Any pixels in the relevant area of this image are replaced.
00291       *
00292       * @param image The MicroBitImage to paste.
00293       *
00294       * @param x The leftmost X co-ordinate in this image where the given image should be pasted. Defaults to 0.
00295       *
00296       * @param y The uppermost Y co-ordinate in this image where the given image should be pasted. Defaults to 0.
00297       *
00298       * @param alpha set to 1 if transparency clear pixels in given image should be treated as transparent. Set to 0 otherwise.  Defaults to 0.
00299       *
00300       * @return The number of pixels written.
00301       *
00302       * @code
00303       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00304       * MicroBitImage i(10,5,heart); // a big heart
00305       * i.paste(i, -5, 0); // a small heart
00306       * @endcode
00307       */
00308     int paste(const MicroBitImage &image, int16_t x = 0, int16_t y = 0, uint8_t alpha = 0);
00309 
00310      /**
00311        * Prints a character to the display at the given location
00312        *
00313        * @param c The character to display.
00314        *
00315        * @param x The x co-ordinate of on the image to place the top left of the character. Defaults to 0.
00316        *
00317        * @param y The y co-ordinate of on the image to place the top left of the character. Defaults to 0.
00318        *
00319        * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER.
00320        *
00321        * @code
00322        * MicroBitImage i(5,5);
00323        * i.print('a');
00324        * @endcode
00325        */
00326     int print(char c, int16_t x = 0, int16_t y = 0);
00327 
00328     /**
00329       * Shifts the pixels in this Image a given number of pixels to the left.
00330       *
00331       * @param n The number of pixels to shift.
00332       *
00333       * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER.
00334       *
00335       * @code
00336       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00337       * MicroBitImage i(10,5,heart); // a big heart
00338       * i.shiftLeft(5); // a small heart
00339       * @endcode
00340       */
00341     int shiftLeft(int16_t n);
00342 
00343     /**
00344       * Shifts the pixels in this Image a given number of pixels to the right.
00345       *
00346       * @param n The number of pixels to shift.
00347       *
00348       * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER.
00349       *
00350       * @code
00351       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00352       * MicroBitImage i(10,5,heart); // a big heart
00353       * i.shiftLeft(5); // a small heart
00354       * i.shiftRight(5); // a big heart
00355       * @endcode
00356       */
00357     int shiftRight(int16_t n);
00358 
00359     /**
00360       * Shifts the pixels in this Image a given number of pixels to upward.
00361       *
00362       * @param n The number of pixels to shift.
00363       *
00364       * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER.
00365       *
00366       * @code
00367       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00368       * MicroBitImage i(10,5,heart);
00369       * i.shiftUp(1);
00370       * @endcode
00371       */
00372     int shiftUp(int16_t n);
00373 
00374     /**
00375       * Shifts the pixels in this Image a given number of pixels to downward.
00376       *
00377       * @param n The number of pixels to shift.
00378       *
00379       * @return MICROBIT_OK on success, or MICROBIT_INVALID_PARAMETER.
00380       *
00381       * @code
00382       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00383       * MicroBitImage i(10,5,heart);
00384       * i.shiftDown(1);
00385       * @endcode
00386       */
00387     int shiftDown(int16_t n);
00388 
00389     /**
00390       * Gets the width of this image.
00391       *
00392       * @return The width of this image.
00393       *
00394       * @code
00395       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00396       * MicroBitImage i(10,5,heart);
00397       * i.getWidth(); // equals 10...
00398       * @endcode
00399       */
00400     int getWidth() const
00401     {
00402         return ptr->width;
00403     }
00404 
00405     /**
00406       * Gets the height of this image.
00407       *
00408       * @return The height of this image.
00409       *
00410       * @code
00411       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00412       * MicroBitImage i(10,5,heart);
00413       * i.getHeight(); // equals 5...
00414       * @endcode
00415       */
00416     int getHeight() const
00417     {
00418         return ptr->height;
00419     }
00420 
00421     /**
00422       * Gets number of bytes in the bitmap, ie., width * height.
00423       *
00424       * @return The size of the bitmap.
00425       *
00426       * @code
00427       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00428       * MicroBitImage i(10,5,heart);
00429       * i.getSize(); // equals 50...
00430       * @endcode
00431       */
00432     int getSize() const
00433     {
00434         return ptr->width * ptr->height;
00435     }
00436 
00437     /**
00438       * Converts the bitmap to a csv ManagedString.
00439       *
00440       * @code
00441       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00442       * MicroBitImage i(10,5,heart);
00443       * uBit.serial.printString(i.toString()); // "0,1,0,1,0,0,0,0,0,0\n..."
00444       * @endcode
00445       */
00446     ManagedString toString();
00447 
00448     /**
00449       * Crops the image to the given dimensions.
00450       *
00451       * @param startx the location to start the crop in the x-axis
00452       *
00453       * @param starty the location to start the crop in the y-axis
00454       *
00455       * @param width the width of the desired cropped region
00456       *
00457       * @param height the height of the desired cropped region
00458       *
00459       * @code
00460       * const uint8_t heart[] = { 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, }; // a cute heart
00461       * MicroBitImage i(10,5,heart);
00462       * i.crop(0,0,2,2).toString() // "0,1\n1,1\n"
00463       * @endcode
00464       */
00465     MicroBitImage crop(int startx, int starty, int finx, int finy);
00466 
00467     /**
00468       * Check if image is read-only (i.e., residing in flash).
00469       */
00470     bool isReadOnly();
00471 
00472     /**
00473       * Create a copy of the image bitmap. Used particularly, when isReadOnly() is true.
00474       *
00475       * @return an instance of MicroBitImage which can be modified independently of the current instance
00476       */
00477     MicroBitImage clone();
00478 };
00479 
00480 #endif