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carbon: reimplement linear gradient using CGShadingRef since LinearGradient is supported since OS X 10.5

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git-svn-id: trunk@38743 -
This commit is contained in:
paul 2012-09-19 04:41:20 +00:00
parent 977f05a8ef
commit f997ff974d
1 changed files with 104 additions and 54 deletions
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158
lcl/interfaces/carbon/carbonwinapi.inc
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@ -2280,6 +2280,80 @@ begin
{$ENDIF}
end;
type
TColorComponents = array[0..3] of CGFloat;
PLinearGradientInfo = ^TLinearGradientInfo;
TLinearGradientInfo = record
colors: array[0..1] of TColorComponents;
end;
function VertexToColor(AVertex: tagTRIVERTEX): TColorComponents;
var
TheAlpha: Byte;
begin
TheAlpha := AVertex.Alpha shr 8;
if TheAlpha = 0 then
TheAlpha := 255;
with AVertex do
begin
Result[0] := (Red shr 8) / 255;
Result[1] := (Green shr 8) / 255;
Result[2] := (Blue shr 8 )/ 255;
Result[3] := TheAlpha / 255;
end;
end;
function LinearGradientCreateInfo(TL, BR: tagTRIVERTEX): UnivPtr;
var
Swap: Longint;
SwapColors: Boolean;
Info: PLinearGradientInfo;
Tmp: TColorComponents;
begin
GetMem(Info, SizeOf(TLinearGradientInfo));
SwapColors := (BR.Y < TL.Y) and (BR.X < TL.X);
if BR.X < TL.X then
begin
Swap := BR.X;
BR.X := TL.X;
TL.X := Swap;
end;
if BR.Y < TL.Y then
begin
Swap := BR.Y;
BR.Y := TL.Y;
TL.Y := Swap;
end;
Info^.colors[0] := VertexToColor(TL);
Info^.colors[1] := VertexToColor(BR);
if SwapColors then
begin
Tmp := Info^.colors[0];
Info^.colors[0] := Info^.colors[1];
Info^.colors[1] := Tmp;
end;
end;
procedure LinearGradientReleaseInfo(info: UnivPtr); mwpascal;
begin
FreeMem(info);
end;
procedure LinearGradientEvaluate(info: UnivPtr; inputValue: CGFloatPtr; outputValue: CGFloatPtr); mwpascal;
var
GradientInfo: PLinearGradientInfo absolute info;
Position: CGFloat;
I: Integer;
begin
Position := inputValue^;
if Position = 0 then
System.Move(GradientInfo^.colors[0], outputValue^, SizeOf(TColorComponents))
else
for I := 0 to 3 do
outputValue[I] := GradientInfo^.colors[0][I] + Position * (GradientInfo^.colors[1][I] - GradientInfo^.colors[0][I]);
end;
function TCarbonWidgetSet.GradientFill(DC: HDC; Vertices: PTriVertex;
NumVertices: Longint; Meshes: Pointer; NumMeshes: Longint; Mode: Longint
): Boolean;
@ -2294,24 +2368,6 @@ function TCarbonWidgetSet.GradientFill(DC: HDC; Vertices: PTriVertex;
Result := (Mode and GRADIENT_FILL_RECT_V) = GRADIENT_FILL_RECT_V;
end;
function VertexToColor(AVertex: tagTRIVERTEX): CGColorRef;
var
TheAlpha: Byte;
F: array[0..3] of Single;
begin
TheAlpha := AVertex.Alpha shr 8;
if TheAlpha = 0 then
TheAlpha := 255;
with AVertex do
begin
F[0] := (Red shr 8) / 255;
F[1] := (Green shr 8) / 255;
F[2] := (Blue shr 8 )/ 255;
F[3] := TheAlpha / 255;
end;
Result := CGColorCreate(RGBColorSpace, @F[0]);
end;
function FillTriMesh(Mesh: tagGradientTriangle) : Boolean;
{
var
@ -2385,13 +2441,14 @@ function TCarbonWidgetSet.GradientFill(DC: HDC; Vertices: PTriVertex;
function FillRectMesh(Mesh: tagGradientRect) : boolean;
var
TL,BR: tagTRIVERTEX;
Colors: array[0..2] of CGColorRef;
ColArray: CFArrayRef;
Swap: Longint;
SwapColors: Boolean;
Grad: CGGradientRef;
TL, BR: tagTRIVERTEX;
Shading: CGShadingRef;
ShadingFunction: CGFunctionRef;
ShadingCallbacks: CGFunctionCallbacks;
Context: CGContextRef;
domain: array[0..1] of CGFloat;
range: array[0..7] of CGFloat;
info: UnivPtr;
begin
with Mesh do
begin
@ -2403,42 +2460,35 @@ function TCarbonWidgetSet.GradientFill(DC: HDC; Vertices: PTriVertex;
TL := Vertices[UpperLeft];
BR := Vertices[LowerRight];
SwapColors := (BR.Y < TL.Y) and (BR.X < TL.X);
if BR.X < TL.X then
begin
Swap := BR.X;
BR.X := TL.X;
TL.X := Swap;
end;
if BR.Y < TL.Y then
begin
Swap := BR.Y;
BR.Y := TL.Y;
TL.Y := Swap;
end;
Colors[0] := VertexToColor(TL);
Colors[1] := VertexToColor(BR);
if SwapColors then
begin
Colors[2] := Colors[0];
Colors[0] := Colors[1];
Colors[1] := Colors[2];
end;
// create array of colors which is needed for CGGradientRef
ColArray := CFArrayCreate(nil, @Colors[0], 2, nil);
Grad := CGGradientCreateWithColors(RGBColorSpace, ColArray, nil);
CFRelease(ColArray);
// to draw a gradient in a rectangle we need to first clip it by that
// rectangle and only then draw the gradient
info := LinearGradientCreateInfo(TL, BR);
Context := TCarbonDeviceContext(DC).CGContext;
CGContextSaveGState(Context);
// to draw a gradient in a rectangle we need to first clip it by that
// rectangle and only then draw the gradient
CGContextAddRect(Context, CGRectMake(TL.X, TL.Y, BR.X - TL.X, BR.Y - TL.Y));
CGContextClip(Context);
ShadingCallbacks.version := 0;
ShadingCallbacks.evaluate := @LinearGradientEvaluate;
ShadingCallbacks.releaseInfo := @LinearGradientReleaseInfo;
domain[0] := 0;
domain[1] := 1;
range[0] := 0;
range[1] := 1;
range[2] := 0;
range[3] := 1;
range[4] := 0;
range[5] := 1;
range[6] := 0;
range[7] := 1;
ShadingFunction := CGFunctionCreate(Info, 1, @domain[0], 4, @range[0], ShadingCallbacks);
if DoFillVRect then
CGContextDrawLinearGradient(Context, Grad, CGPointMake(TL.X, TL.Y), CGPointMake(TL.X, BR.Y), 0)
Shading := CGShadingCreateAxial(RGBColorSpace, CGPointMake(TL.X, TL.Y), CGPointMake(TL.X, BR.Y), ShadingFunction, 0, 0)
else
CGContextDrawLinearGradient(Context, Grad, CGPointMake(TL.X, TL.Y), CGPointMake(BR.X, TL.Y), 0);
CGGradientRelease(Grad);
Shading := CGShadingCreateAxial(RGBColorSpace, CGPointMake(TL.X, TL.Y), CGPointMake(BR.X, TL.Y), ShadingFunction, 0, 0);
CGContextDrawShading(Context, Shading);
CGShadingRelease(Shading);
CGContextRestoreGState(Context);
end;
end;