Put layer in front of all other layers.
Source position: layers.pas line 119
function UpfrontLayer( |
dummy: LongInt; |
layer: pLayer |
):LongInt; |
dummy |
|
unused |
layer |
|
pointer to a nonbackdrop layer |
True if operation successful. False if operation unsuccessful (probably out of memory)
Move this layer to the most upfront position swapping bits in and out of the display with other layers. If this is a refresh layer then collect damage list and set the LAYERREFRESH bit in layer->Flags if redraw required. By clearing the BACKDROP bit in the layers Flags you may bring a Backdrop layer up to the front of all other layers.
Attention
This operation may generate refresh events in other layers associated with this layer's Layer_Info structure.
program LayersTest; { For the sake of brevity, the example is a single task. No Layer locking is done. Also note that the routine MyLabelLayer() is used to redraw a given layer. It is called only when a layer needs refreshing. LayersTest.pp converted from original RKRM layers.c tested with FPC 3.2.0} {$mode fpc} uses Exec, AmigaDOS, AGraphics, Layers; const L_DELAY = 100; S_DELAY = 50; DUMMY = 0; RED_PEN = 1; GREEN_PEN = 2; BLUE_PEN = 3; SCREEN_D = 2; SCREEN_W = 320; SCREEN_H = 200; // the starting size of example layers, offsets are used for placement W_H = 50; W_T = 5; W_B = (W_T + W_H) - 1; W_W = 80; W_L = (SCREEN_W div 2) - (W_W div 2); W_R = (W_L + W_W) - 1; // size of the superbitmap SUPER_H = SCREEN_H; SUPER_W = SCREEN_W; // starting size of the message layer M_H = 10; M_T = SCREEN_H - M_H; M_B = (M_T + M_H) - 1; M_W = SCREEN_W; M_L = 0; M_R = (M_L + M_W) - 1; // global constant data for initializing the layers TheLayerFlags: array[0..2] of LongInt = (LAYERSUPER, LAYERSMART, LAYERSIMPLE); ColorTable: array [0..3] of Word = ($000, $f44, $4f4, $44f); // Clear the layer then draw in a text string. procedure MyLabelLayer(Layer: PLayer; Color: LongInt; str: AnsiString); begin // fill Layer with color SetRast(Layer^.rp, Color); // set up for writing text into Layer SetDrMd(Layer^.rp, JAM1); SetAPen(Layer^.rp, 0); GfxMove(Layer^.rp, 5, 7); // write into Layer GfxText(Layer^.rp, PChar(str), Length(str)); end; // write a message into a layer with a delay. procedure DoMessage(Layer: PLayer; Str: AnsiString); begin DOSDelay(S_DELAY); MyLabelLayer(Layer, GREEN_PEN, str); end; // write an error message into a layer with a delay. procedure Error(Layer: PLayer; Str: AnsiString); begin MyLabelLayer(Layer, RED_PEN, Str); DOSDelay(L_DELAY); end; // do some layers manipulations to demonstrate their abilities. procedure DoLayers(MsgLayer: PLayer; var Layer_Array: array of PLayer); var ktr: SmallInt; ktr_2: SmallInt; begin DoMessage(MsgLayer, 'Label all Layers'); MyLabelLayer(Layer_Array[0], RED_PEN, 'Super'); MyLabelLayer(Layer_Array[1], GREEN_PEN, 'Smart'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'MoveLayer 1 InFrontOf 0'); if not Boolean(MoveLayerInFrontOf(Layer_Array[1], Layer_Array[0])) then Error(MsgLayer, 'MoveLayerInFrontOf() failed.'); DoMessage(MsgLayer, 'MoveLayer 2 InFrontOf 1'); if not Boolean(MoveLayerInFrontOf(Layer_Array[2], Layer_Array[1])) then Error(MsgLayer, 'MoveLayerInFrontOf() failed.'); DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'Incrementally MoveLayers...'); for ktr := 0 to 29 do begin if not Boolean(MoveLayer(DUMMY, Layer_Array[1], -1, 0)) then Error(MsgLayer, 'MoveLayer() failed.'); if not Boolean(MoveLayer(DUMMY, Layer_Array[2], -2, 0)) then Error(MsgLayer, 'MoveLayer() failed.'); end; DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'make Layer 0 the UpfrontLayer'); if not Boolean(UpfrontLayer(DUMMY, Layer_Array[0])) then Error(MsgLayer, 'UpfrontLayer() failed.'); DoMessage(MsgLayer, 'make Layer 2 the BehindLayer'); if not Boolean(BehindLayer(DUMMY, Layer_Array[2])) then Error(MsgLayer, 'BehindLayer() failed.'); DoMessage(MsgLayer, 'Incrementally MoveLayers again...'); for ktr := 0 to Pred(30) do begin if not Boolean(MoveLayer(DUMMY, Layer_Array[1], 0, 1)) then Error(MsgLayer, 'MoveLayer() failed.'); if not Boolean(MoveLayer(DUMMY, Layer_Array[2], 0, 2)) then Error(MsgLayer, 'MoveLayer() failed.'); end; DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'Big MoveLayer'); for ktr := 0 to High(Layer_Array) do if not Boolean(MoveLayer(DUMMY, Layer_Array[ktr], -Layer_Array[ktr]^.bounds.MinX, 0)) then Error(MsgLayer, 'MoveLayer() failed.'); DoMessage(MsgLayer, 'Incrementally increase size'); for ktr := 0 to 4 do for ktr_2 := 0 to High(Layer_Array) do if not Boolean(SizeLayer(DUMMY, Layer_Array[ktr_2], 1, 1)) then Error(MsgLayer, 'SizeLayer() failed.'); DoMessage(MsgLayer, 'Refresh Smart Refresh Layer'); MyLabelLayer(Layer_Array[1], GREEN_PEN, 'Smart'); DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'Big SizeLayer'); for ktr := 0 to High(Layer_Array) do if not Boolean(SizeLayer(DUMMY, Layer_Array[ktr], SCREEN_W - (Layer_Array[ktr]^.bounds.MaxX) - 1, 0)) then Error(MsgLayer, 'SizeLayer() failed.'); DoMessage(MsgLayer, 'Refresh Smart Refresh Layer'); MyLabelLayer(Layer_Array[1], GREEN_PEN, 'Smart'); DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'ScrollLayer down'); for ktr := 0 to 29 do for ktr_2 := 0 to High(Layer_Array) do ScrollLayer(DUMMY, Layer_Array[ktr_2], 0, -1); DoMessage(MsgLayer, 'Refresh Smart Refresh Layer'); MyLabelLayer(Layer_Array[1], GREEN_PEN, 'Smart'); DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DoMessage(MsgLayer, 'ScrollLayer up'); for ktr := 0 to 29 do for ktr_2 := 0 to High(Layer_Array) do ScrollLayer(DUMMY, Layer_Array[ktr_2], 0, 1); DoMessage(MsgLayer, 'Refresh Smart Refresh Layer'); MyLabelLayer(Layer_Array[1], GREEN_PEN, 'Smart'); DoMessage(MsgLayer, 'Refresh Simple Refresh Layer'); MyLabelLayer(Layer_Array[2], BLUE_PEN, 'Simple'); DOSDelay(L_DELAY); end; // delete the layer array created by allocLayers(). procedure DisposeLayers(MsgLayer: PLayer; var Layer_Array: array of PLayer); var ktr: SmallInt; begin for ktr := 0 to High(Layer_Array) do if (Layer_Array[ktr] <> nil) then if not Boolean(DeleteLayer(DUMMY, Layer_Array[ktr])) then Error(MsgLayer, 'Error deleting layer'); end; {Create some hard-coded layers. The first must be super-bitmap, with the bitmap passed as an argument. The others must not be super-bitmap. The pointers to the created layers are returned in Layer_Array. Return False on failure. On a False return, the layers are properly cleaned up.} function AllocLayers(MsgLayer: PLayer; var Layer_Array: array of PLayer; Super_Bitmap: PBitmap; TheLayerInfo: PLayer_Info; TheBitMap: PBitMap): Boolean; var ktr: SmallInt; Create_Layer_Ok: Boolean = True; begin ktr := 0; while (ktr < Length(Layer_Array)) and (Create_Layer_Ok) do begin DoMessage(MsgLayer, 'Create BehindLayer'); if ktr = 0 then begin Layer_Array[ktr] := CreateBehindLayer(TheLayerInfo, TheBitMap, W_L + (ktr * 30), W_T + (ktr * 30), W_R + (ktr * 30), W_B + (ktr * 30), TheLayerFlags[ktr], Super_Bitmap); if not Assigned(Layer_Array[ktr]) then Create_Layer_Ok := False; end else begin Layer_Array[ktr] := CreateBehindLayer(TheLayerInfo, TheBitMap, W_L + (ktr * 30), W_T + (ktr * 30), W_R + (ktr * 30), W_B + (ktr * 30), TheLayerFlags[ktr], nil); if not Assigned(Layer_Array[ktr]) then Create_Layer_Ok := FALSE; end; if Create_Layer_Ok then begin DoMessage(MsgLayer, 'Fill the RastPort'); SetRast(Layer_Array[ktr]^.rp, ktr + 1); end; Inc(ktr); end; if not Create_Layer_Ok then DisposeLayers(MsgLayer, Layer_Array); AllocLayers := Create_Layer_Ok; end; // Set up to run the layers example, doLayers(). Clean up when done. procedure StartLayers(TheLayerInfo: PLayer_Info; TheBitMap: PBitMap); var MsgLayer: PLayer; TheSuperBitMap: PBitMap; TheLayers: array[0..2] of PLayer = (nil, nil, nil); begin MsgLayer := CreateUpfrontLayer(TheLayerInfo, TheBitMap, M_L, M_T, M_R, M_B, LAYERSMART, nil); if Assigned(MsgLayer) then begin DoMessage(MsgLayer, 'Setting up Layers'); TheSuperBitMap := AllocBitMap(SUPER_W, SUPER_H, SCREEN_D, BMF_CLEAR or BMF_DISPLAYABLE, nil); if Assigned(TheSuperBitMap) then begin if Boolean(AllocLayers(MsgLayer, TheLayers, TheSuperBitMap, TheLayerInfo, TheBitMap)) then begin DoLayers(MsgLayer, TheLayers); DisposeLayers(MsgLayer, TheLayers); end; FreeBitMap(TheSuperBitMap); end; if not Boolean(DeleteLayer(DUMMY, MsgLayer)) then Error(MsgLayer, 'Error deleting layer'); end; end; { Set up a low-level graphics display for layers to work on. Layers should not be built directly on Intuition screens, use a low-level graphics view. If you need mouse or other events for the layers display, you have to get them directly from the input device. The only supported method of using layers library calls with Intuition (other than the InstallClipRegion() call) is through Intuition windows. See graphics primitives chapter for details on creating and using the low-level graphics calls.} procedure RunNewView; var TheView: TView; Oldview: PView; TheViewPort: TViewPort; TheRasInfo: TRasInfo; TheColorMap: PColorMap; TheLayerInfo: PLayer_Info; TheBitMap: PBitMap; ColorPalette: PWord; ktr: SmallInt; begin //* save current view, to be restored when done */ Oldview := PGfxBase(GfxBase)^.ActiView; if Assigned(Oldview) then begin //* get a LayerInfo structure */ TheLayerInfo := NewLayerInfo; if Assigned(TheLayerInfo) then begin TheColorMap := GetColorMap(4); if Assigned(TheColorMap) then begin ColorPalette := PWord(TheColorMap^.ColorTable); for ktr := 0 to 3 do begin ColorPalette^ := colortable[ktr]; Inc(ColorPalette); end; TheBitMap := AllocBitMap(SCREEN_W, SCREEN_H, SCREEN_D, BMF_CLEAR or BMF_DISPLAYABLE, nil); if Assigned(TheBitMap) then begin InitView(@TheView); InitVPort(@TheViewPort); TheView.ViewPort := @TheViewPort; TheViewPort.DWidth := SCREEN_W; TheViewPort.DHeight := SCREEN_H; TheViewPort.RasInfo := @TheRasInfo; TheViewPort.ColorMap := TheColorMap; TheRasInfo.BitMap := TheBitMap; TheRasInfo.RxOffset := 0; TheRasInfo.RyOffset := 0; TheRasInfo.Next := nil; MakeVPort(@TheView, @TheViewPort); MrgCop(@TheView); LoadView(@TheView); WaitTOF; StartLayers(TheLayerInfo, TheBitMap); // put back the old view, wait for it to become active before freeing any of our display LoadView(Oldview); WaitTOF; // free dynamically created structures FreeVPortCopLists(@TheViewPort); FreeCprList(TheView.LOFCprList); FreeBitMap(TheBitMap); end; FreeColorMap(TheColorMap); // free the color map end; DisposeLayerInfo(TheLayerInfo); end; end; end; begin RunNewView; end.