/* Example 2 */ /* This example shows how to create a large Raster and a smaller */ /* display. We fill the Raster with a lot of pixels in seven different */ /* colours and by altering the RxOffset and RyOffset values in the */ /* RasInfo structure, the Raster is scrolled in all directions. This */ /* method to scroll a large drawing in full speed is used in many games */ /* and was even used in my own racing game "Car". */ #include #include #define RWIDTH 450 /* Raster 450 pixels wide. */ #define RHEIGHT 250 /* Raster 250 lines high. */ /* The ViewPort is quite small, and is placed in the middle of the View: */ #define DWIDTH 200 /* Display 200 pixels wide. */ #define DHEIGHT 100 /* Display 100 lines high. */ #define DXOFFSET 60 /* DxOffset 60 pixels. */ #define DYOFFSET 50 /* DyOffset 50 lines. */ #define DEPTH 3 /* 3 BitPlanes should be used, gives eight colours. */ #define COLOURS 8 /* 2^3 = 8 */ #define SPEED 1 /* How many pixels the Raster should be scrolled */ /* every time. */ struct IntuitionBase *IntuitionBase; struct GfxBase *GfxBase; struct View my_view; struct View *my_old_view; struct ViewPort my_view_port; struct RasInfo my_ras_info; struct BitMap my_bit_map; struct RastPort my_rast_port; UWORD my_color_table[] = { 0x000, /* Colour 0, Black */ 0x800, /* Colour 1, Red */ 0xF00, /* Colour 2, Light red */ 0x080, /* Colour 3, Green */ 0x0F0, /* Colour 4, Light green */ 0x008, /* Colour 5, Blue */ 0x00F, /* Colour 6, Light Blue */ 0xFFF, /* Colour 7, White */ }; void clean_up(); void main(); void main() { SHORT deltaX = SPEED; SHORT deltaY = SPEED; UWORD *pointer; int loop; /* Open the Intuition library: */ IntuitionBase = (struct IntuitionBase *) OpenLibrary( "intuition.library", 0 ); if( !IntuitionBase ) clean_up( "Could NOT open the Intuition library!" ); /* Open the Graphics library: */ GfxBase = (struct GfxBase *) OpenLibrary( "graphics.library", 0 ); if( !GfxBase ) clean_up( "Could NOT open the Graphics library!" ); /* Save the current View, so we can restore it later: */ my_old_view = GfxBase->ActiView; /* 1. Prepare the View structure, and give it a pointer to */ /* the first ViewPort: */ InitView( &my_view ); my_view.ViewPort = &my_view_port; /* 2. Prepare the ViewPort structure, and set some important values: */ InitVPort( &my_view_port ); my_view_port.DWidth = DWIDTH; /* Set the width. */ my_view_port.DHeight = DHEIGHT; /* Set the height. */ my_view_port.DxOffset = DXOFFSET; /* Set the display X offset. */ my_view_port.DyOffset = DYOFFSET; /* Set the display Y offset. */ my_view_port.RasInfo = &my_ras_info; /* Give it a pointer to RasInfo. */ my_view_port.Modes = NULL; /* Low resolution. */ /* 3. Get a colour map, link it to the ViewPort, and prepare it: */ my_view_port.ColorMap = (struct ColorMap *) GetColorMap( COLOURS ); if( my_view_port.ColorMap == NULL ) clean_up( "Could NOT get a ColorMap!" ); /* Get a pointer to the colour map: */ pointer = (UWORD *) my_view_port.ColorMap->ColorTable; /* Set the colours: */ for( loop = 0; loop < COLOURS; loop++ ) *pointer++ = my_color_table[ loop ]; /* 4. Prepare the BitMap: */ InitBitMap( &my_bit_map, DEPTH, RWIDTH, RHEIGHT ); /* Allocate memory for the Raster: */ for( loop = 0; loop < DEPTH; loop++ ) { my_bit_map.Planes[ loop ] = (PLANEPTR) AllocRaster( RWIDTH, RHEIGHT ); if( my_bit_map.Planes[ loop ] == NULL ) clean_up( "Could NOT allocate enough memory for the raster!" ); /* Clear the display memory with help of the Blitter: */ BltClear( my_bit_map.Planes[ loop ], RASSIZE( RWIDTH, RHEIGHT ), 0 ); } /* 5. Prepare the RasInfo structure: */ my_ras_info.BitMap = &my_bit_map; /* Pointer to the BitMap structure. */ my_ras_info.RxOffset = 0; /* The top left corner of the Raster */ my_ras_info.RyOffset = 0; /* should be at the top left corner */ /* of the display. */ my_ras_info.Next = NULL; /* Single playfield - only one */ /* RasInfo structure is necessary. */ /* 6. Create the display: */ MakeVPort( &my_view, &my_view_port ); MrgCop( &my_view ); /* 7. Prepare the RastPort, and give it a pointer to the BitMap. */ InitRastPort( &my_rast_port ); my_rast_port.BitMap = &my_bit_map; /* 8. Show the new View: */ LoadView( &my_view ); /* Set the draw mode to JAM1. FgPen's colour will be used. */ SetDrMd( &my_rast_port, JAM1 ); /* Draw 10000 pixels in seven different colours, randomly. */ for( loop = 0; loop < 10000; loop++ ) { /* Set FgPen's colour (1-7, 0 used for the the background). */ SetAPen( &my_rast_port, rand() % (COLOURS-1) + 1 ); /* Write a pixel somewere on the display: */ WritePixel( &my_rast_port, rand() % RWIDTH, rand() % RHEIGHT ); } /* Scroll the Raster in all directions for a little while: */ for( loop = 0; loop < 5000; loop++ ) { my_ras_info.RxOffset += deltaX; my_ras_info.RyOffset += deltaY; /* The Raster is moved in one direction until the other side is */ /* reached were we change the direction: */ /* Have we reached the left side? */ if( my_ras_info.RxOffset <= 0 ) deltaX = SPEED; /* Have we reached the right (Raster width - Display width) side? */ if( my_ras_info.RxOffset >= RWIDTH - DWIDTH ) deltaX = -SPEED; /* Have we reached the top side? */ if( my_ras_info.RyOffset <= 0 ) deltaY = SPEED; /* Have we reached the bottom (Raster height - Display height) side? */ if( my_ras_info.RyOffset >= RHEIGHT - DHEIGHT ) deltaY = -SPEED; /* Recalculate the display instructions: (If you change any values */ /* in the display structures the Amiga have to recalculate the */ /* entire display instructions. You must therefore call all three */ /* display functions: MakeVPort(), MrgCop() and LoadView().) */ MakeVPort( &my_view, &my_view_port ); MrgCop( &my_view ); LoadView( &my_view ); } /* 9. Restore the old View: */ LoadView( my_old_view ); /* Free all allocated resources and leave. */ clean_up( "THE END" ); } /* Returns all allocated resources: */ void clean_up( message ) STRPTR message; { int loop; /* Free automatically allocated display structures: */ FreeVPortCopLists( &my_view_port ); FreeCprList( my_view.LOFCprList ); /* Deallocate the display memory, BitPlane for BitPlane: */ for( loop = 0; loop < DEPTH; loop++ ) if( my_bit_map.Planes[ loop ] ) FreeRaster( my_bit_map.Planes[ loop ], RWIDTH, RHEIGHT ); /* Deallocate the ColorMap: */ if( my_view_port.ColorMap ) FreeColorMap( my_view_port.ColorMap ); /* Close the Graphics library: */ if( GfxBase ) CloseLibrary( GfxBase ); /* Close the Intuition library: */ if( IntuitionBase ) CloseLibrary( IntuitionBase ); /* Print the message and leave: */ printf( "%s\n", message ); exit(); }