- Bitmap Images
Bitmap images are binary files which contain a pixel by pixel description of a graphical image.. The value of each pixel is stored in one or more bits of data as defined by the color depth, or bits per pixel (bpp).
The amount of memory required to store images can be quite large. Click Here to see a chart of how images size and color density can effect the memory requirements. To conserve the application's program memory it is possible to store images and fonts in external non-volatile memory.
Importing Bitmap images
The Graphics Resource Converter utility (GRC) is used to import graphics images. (This is the same utility used to import fonts). The GRC can import images from bitmap files (.BMP) or JPEG files (.JPG or .JPEG).
The GRC is located in the MLA Installation directory:
Linux and Apple OSX users launch the resource converter by executing grc.jar, and Microsoft Windows users invoke it by executing launch_grc.bat
Using Bitmap Images
Once the image has been imported into the project and rebuilt you will be able to display the image on the screen. To reference an imported image you refer to the image by the name given in the header file. When an image file is converted you will be prompted to enter the name of the file to store the image. This example uses NewImage as the name of the image file.
Example of MPLAB® X IDE's project tree with the assembly (.s), header (.h), and C (.c) files added.
Function used to Output an Image
GFX_ImageDraw( left, top, &image) displays the image on the screen at the coordinates designated.
Helpful Functions to Position Images on the Screen
The following functions can be useful to position your images (and objects) on the screen
GFX_MaxXGet() returns the width (in pixels) of the display
GFX_MaxYGet() returns the height (in pixels) of the display
GFX_ImageWidthGet( GFX_RESOURCE_HDR * pImage) returns the width, in pixels, of the image.
GFX_ImageHeightGet(GFX_RESOURCE_HDR * |pImage) returns the height, in pixels, of the image.