134 lines
4.0 KiB
ObjectPascal

unit utexture;
{$mode objfpc}{$H+}
interface
{ This unit creates textures. It is mainly based on Perlin noise maps,
which are random maps that have a natural look. Then a color is applied
by linear interpolation. The water texture is achieved by using
a Phong lighting based on the Perlin noise map. }
uses
Classes, SysUtils, BGRABitmap, BGRABitmapTypes;
function CreateGrassTexture(tx,ty: integer): TBGRABitmap;
function CreateVerticalWoodTexture(tx, ty: integer): TBGRABitmap;
function CreateWoodTexture(tx,ty: integer): TBGRABitmap;
function CreateWaterTexture(tx,ty: integer): TBGRABitmap;
implementation
uses {$IFNDEF NO_OPENGL_SURFACE}BGRAOpenGL, {$ENDIF}BGRAGradients;
function Interp256(value1,value2,position: integer): integer; inline;
begin
result := (value1*(256-position)+value2*position) shr 8;
end;
function Interp256(color1,color2: TBGRAPixel; position: integer): TBGRAPixel; inline;
begin
result.red := Interp256(color1.red,color2.red,position);
result.green := Interp256(color1.green,color2.green,position);
result.blue := Interp256(color1.blue,color2.blue,position);
result.alpha := Interp256(color1.alpha,color2.alpha,position);
end;
function CreateWoodTexture(tx,ty: integer): TBGRABitmap;
var
colorOscillation, globalColorVariation: integer;
p: PBGRAPixel;
i: Integer;
begin
result := CreateCyclicPerlinNoiseMap(tx,ty,1.5,1.5,1,rfBestQuality);
p := result.Data;
for i := 0 to result.NbPixels-1 do
begin
colorOscillation := round(sqrt((sin(p^.red*Pi/16)+1)/2)*256);
globalColorVariation := p^.red;
p^:= Interp256( Interp256(BGRA(247,188,120),BGRA(255,218,170),colorOscillation),
Interp256(BGRA(157,97,60),BGRA(202,145,112),colorOscillation), globalColorVariation);
inc(p);
end;
{$IFNDEF NO_OPENGL_SURFACE}
BGRAReplace(result, TBGLBitmap.Create(result));
{$ENDIF}
end;
function CreateVerticalWoodTexture(tx, ty: integer): TBGRABitmap;
var
globalPos: single;
colorOscillation, globalColorVariation: integer;
p: PBGRAPixel;
i: Integer;
x,nbVertical: integer;
begin
result := CreateCyclicPerlinNoiseMap(tx,ty,1,1,1,rfBestQuality);
p := result.Data;
x := 0;
nbVertical := tx div 128;
if nbVertical = 0 then nbVertical := 1;
for i := 0 to result.NbPixels-1 do
begin
globalPos := p^.red*Pi/32 + nbVertical*x*2*Pi/tx*8;
colorOscillation := round(sqrt((sin(globalPos)+1)/2)*256);
globalColorVariation := p^.red; //round(sin(globalPos/8)*128+128);
p^:= Interp256( Interp256(BGRA(247,188,120),BGRA(255,218,170),colorOscillation),
Interp256(BGRA(157,97,60),BGRA(202,145,112),colorOscillation), globalColorVariation);
inc(p);
inc(x);
if x = tx then x := 0;
end;
{$IFNDEF NO_OPENGL_SURFACE}
BGRAReplace(result, TBGLBitmap.Create(result));
{$ENDIF}
end;
function CreateGrassTexture(tx,ty: integer): TBGRABitmap;
var
p: PBGRAPixel;
i: Integer;
begin
result := CreateCyclicPerlinNoiseMap(tx,ty,1,1,1,rfBestQuality);
p := result.Data;
for i := 0 to result.NbPixels-1 do
begin
p^ := Interp256( BGRA(0,128,0), BGRA(192,255,0), p^.red );
inc(p);
end;
{$IFNDEF NO_OPENGL_SURFACE}
BGRAReplace(result, TBGLBitmap.Create(result));
{$ENDIF}
end;
function CreateWaterTexture(tx,ty: integer): TBGRABitmap;
const blurSize = 5;
var
map: TBGRABitmap;
phong: TPhongShading;
begin
result := TBGRABitmap.Create(tx,ty);
map := CreateCyclicPerlinNoiseMap(tx,ty,1,1,1.2,rfBestQuality);
BGRAReplace(map,map.GetPart(rect(-blurSize,-blurSize,tx+blurSize,ty+blurSize)));
BGRAReplace(map,map.FilterBlurRadial(blurSize,rbFast));
phong := TPhongShading.Create;
phong.LightSourceDistanceFactor := 0;
phong.LightDestFactor := 0;
phong.LightSourceIntensity := 150;
phong.LightPositionZ := 80;
phong.LightColor := BGRA(105,233,240);
phong.NegativeDiffusionFactor := 0.3;
phong.SpecularIndex := 20;
phong.AmbientFactor := 0.4;
phong.Draw(result,map,20,-blurSize,-blurSize,BGRA(28,139,166));
phong.Free;
map.Free;
{$IFNDEF NO_OPENGL_SURFACE}
BGRAReplace(result, TBGLBitmap.Create(result));
{$ENDIF}
end;
end.