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"DigitText"
, by markrosten
Displaying text on a HUD using a custom mesh (and loaded font image)
Code
;Want to display some graphics fonts in your 3d view, but don't want to use overlayed 2d? ;These routines create and update a digit mesh which is essentially a flat mesh using seperate ;surfaces to display your text for a given text string, using a loaded 2d font image for the ;characters. ;The example code shows how to set up your camera in order to get the screen positioning correct, ;as the routines place the digit text mesh in relative 2d space. So you give the create routine 2d x ;and y coordinates and a parent camera, and it places the entity at the correct position in 3d space ;so that the digit mesh's text is the correct pixel size and position relative to your 2d screen. ;The routine that determines which font image frame index to use expects your font image characters ;to be ordered in a certain order. Here is the order: ;Index Character ;----- --------- ;0 , ;1 - ;2 . ;3 / ;4 : ;5 = ;6 ? ;7 0 ;8 1 ;9-16 2-9 ;17 A ;18-43 B-Z ;You can of course just change the UpdateDigitText() function to use a different frame index list ;for your font, which you will need to do anyway to use characters not covered by my font. ;You can download a font image example here: ;http://www.planetflibble.com/rds/digifont.png ;If you have any problems of questions on this code, feel free to email them to me. ;Mark Rosten ;markblitz@planetflibble.com ;================================ code start ;digit sprites for HUD ;by Mark Rosten ;markblitz@planetflibble.com Graphics3D 640,480 ;for example only. not needed ;=================================== declares ;-- hud digit text declares Global digitbrush, digitbrushblank Global digitlasttxt$ ;-- load texture font frames Global fonttexwidth = 16 Global fonttexheight = 16 Global fonttexture = LoadAnimTexture( "digifont.png", 4+16+32, fonttexwidth, fonttexheight, 0, 43 ) If fonttexture = 0 Then RuntimeError( "File 'digifont.png' not found!" ) ;=================================== functions ;------------- create digit entity (for hud display text) Function CreateDigitEntity( parent, numdigits, x, y, CamZoom#=1.0 ) ;-- create work brushes? If Not digitbrush ; create work brushes digitbrush = CreateBrush() digitbrushblank = CreateBrush() ; clear blank digit brush texture ; (reset all pixels in texture to alpha 0, colour 0,0,0 ) tex = CreateTexture(1,1,4) SetBuffer TextureBuffer(tex) For ty=0 To TextureHeight(tex)-1 For tx=0 To TextureWidth(tex)-1 WritePixel tx,ty,0 Next Next SetBuffer BackBuffer() ; assign blank alpha'ed texture to blank work brush BrushTexture digitbrushblank, tex ; release texture FreeTexture tex EndIf ;-- create digit mesh ent = CreateDigitMesh( numdigits, parent ) ;-- adjust start position y by font height y = y + fonttexheight ;-- set entity properties EntityFX ent, 1+4+8 ;full bright, flatshaded, disable fog EntityOrder ent, -1 ;bring to front ;-- position entity relative to camera ; (if you have multiple cameras then you will need to hide the digit entity before ; rendering the cameras that you don't want the digit entity visible in) PositionEntity ent,x-(GraphicsWidth()/2),(GraphicsHeight()/2)-y,(GraphicsWidth()/2) * CamZoom# ;un-comment this to ignore the positioning in 2d space and view as normal mesh ;PositionEntity ent, -50, 0, 100 ;-- return newly created entity Return ent End Function ;------------- create digit mesh (quads joined together. one surf per quad) Function CreateDigitMesh( numdigits=1, parent ) ;-- create mesh mesh = CreateMesh( parent ) ;-- determine x and y sizes for single digit segment xsiz = fonttexwidth-1 ysiz = fonttexheight-1 ;-- create seperate quad per digit segment For digit = 1 To numdigits ; create a surface for this quad surf = CreateSurface( mesh ) ; create corner vertices for quad v0 = AddVertex( surf, x, ysiz, 0, 0, 0 ) ;top left v1 = AddVertex( surf, x+xsiz, ysiz, 0, 1, 0 ) ;top right v2 = AddVertex( surf, x+xsiz, 0, 0, 1, 1 ) ;bottom right v3 = AddVertex( surf, x, 0, 0, 0, 1 ) ;bottom left ; create 2 triangles to create quad AddTriangle surf, v0, v1, v2 AddTriangle surf, v0, v2, v3 ; increment x start position for next quad x = x + xsiz Next ;-- update normals (not sure if needed) UpdateNormals mesh ;-- return newly created mesh Return mesh End Function ;------------- update surface textures for digit mesh to show text Function UpdateDigitText( ent, txt$, newx=-999, newy=-999, camzoom#=1.0 ) ;-- change in position? If newx <> -999 If newx <> digitlastx Or newy <> digitlasty PositionEntity ent,newx-(GraphicsWidth()/2),(GraphicsHeight()/2)-newy,(GraphicsWidth()/2) * CamZoom# EndIf EndIf ;-- if no change in text since last call, then don't need to do anything If txt$ = digitlasttxt$ Then Return ;-- store this text digitlasttxt$ = txt$ ;-- convert to uppercase txt$ = Upper$(txt$) ;-- texture digits 1 to length of passed text For i = 1 To Len(txt$) ; only texture available surfaces If i <= CountSurfaces( ent ) ; get this digit's surface handle surf = GetSurface( ent, i ) ; determine texture frame ; (this is based on layout of font image loaded) f = 0 Select Mid$(txt$,i,1) Case "," f = 0 Case "-" f = 1 Case "." f = 2 Case "/" f = 3 Case ":" f = 4 Case "=" f = 5 Case "?" f = 6 Case "0","1","2","3","4","5","6","7","8","9" f = Int(Mid$(txt$,i,1))+7 Default If Mid$(txt$,i,1) >= "A" And Mid$(txt$,i,1) <= "Z" f = (Asc(Mid$(txt$,i,1)) - 64) + 16 EndIf End Select ; set brush texture and paint surface with it? If f > 0 BrushTexture digitbrush, fonttexture, f PaintSurface surf, digitbrush Else ; no available font character for this digit. so use blank digit PaintSurface surf, digitbrushblank EndIf Else ; text exceeds number of surfaces in digit mesh, so exit loop Exit EndIf Next ;-- clear remaining digits? If Len(txt$) < CountSurfaces( ent ) ; go through remaining digit surfaces.. For i = Len(txt$)+1 To CountSurfaces( ent ) ; get this digit's surface handle surf = GetSurface( ent, i ) ; use blank digit for this surface PaintSurface surf, digitbrushblank Next EndIf End Function ;=================================== example usage ; (remove this section when copying in to your program) ;create light light = CreateLight() ;for test only. not needed ;initialise camera camera = CreateCamera() camzoom# = 1.0 CameraZoom camera,camzoom# CameraRange camera,1,((GraphicsWidth()/2) * camzoom#)+1000 ;setup digit mesh (8 digits in this example) numdigits = 14 mydigit_entity = CreateDigitEntity( camera, numdigits, 64, 64, camzoom# ) ;create cube to rotate in front of camera cube = CreateCube() EntityColor cube, 128,0,0 PositionEntity cube, 0, 0, 5 ;render loop While Not KeyHit(1) test$ = Str$(cnt) : cnt = cnt + 1 If Len(test$) < numdigits Then test$ = String$("0",8-Len(test$)) + test$ test$ = "Test "+test$ ;if mouse button then pass new x/y 2d coordinates to fuction ;otherwise just update digit text If MouseDown(1) And detach=False UpdateDigitText( mydigit_entity, test$, MouseX(), MouseY(), camzoom# ) Else UpdateDigitText( mydigit_entity, test$ ) EndIf ;turn dummy cube TurnEntity cube, .5, 1, .5 ;toggle wireframe on W key If KeyHit(17) showwire = Not showwire WireFrame showwire EndIf ;toggle digit text detach from camera If KeyHit(57) detach = Not detach If detach EntityParent mydigit_entity, cube PositionEntity mydigit_entity, 0, 0, 10 Else EntityParent mydigit_entity, camera RotateEntity mydigit_entity, 0, 0, 0 UpdateDigitText( mydigit_entity, test$, 64, 64, camzoom# ) EndIf EndIf ;update and render world UpdateWorld RenderWorld ;instructions text Text 0,0,"Hold mouse button to move digit text in 2d space" Text 0,12,"Press W to toggle wireframe mode" Text 0,24,"Press SPACE to toggle digit text attachment to camera or cube" Flip Wend End
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