1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
| unit UPng2Bmp32;
interface
uses Windows, SysUtils, Graphics, PngImage;
procedure PartialTransPng2Bmp32(aPNGImage: TPNGImage; aBMP: TBitmap);
implementation
type
// l'astuce qui permet d'avoir accès à la section Protected
// de la classe TChunckIHDR
THackChunkIHDR = class(TChunkIHDR);
{Copy a PNG to a BMP32 using partial transparency
Original code grabed from PngImage.pas:
procedure TPngImage.DrawPartialTrans(DC: HDC; Rect: TRect);
adapted by Cirec}
procedure PartialTransPng2Bmp32(aPNGImage: TPNGImage; aBMP: TBitmap);
type
{Access to pixels}
TPixelLine = Array[Word] of TRGBQuad;
pPixelLine = ^TPixelLine;
var
Header: THackChunkIHDR;
{Transparency/palette chunks}
TransparencyChunk: TChunktRNS;
PaletteChunk: TChunkPLTE;
PaletteIndex: Byte;
CurBit: Integer;
Data: PByte;
{Buffer bitmap modification}
BytesPerRowDest,
BytesPerRowSrc,
BytesPerRowAlpha: Integer;
ImageSource, ImageSourceOrg,
AlphaSource : pByteArray;
ImageData : pPixelLine;
i, j, i2, j2 : Integer;
{For bitmap stretching}
W, H : Cardinal;
Stretch : Boolean;
FactorX, FactorY: Double;
begin
if not Assigned(aBMP) then Exit;
aBMP.PixelFormat := pf32bit;
W := aBMP.Width;
H := aBMP.Height;
Header := THackChunkIHDR(aPNGImage.Header); {Fast access to header}
Stretch := (W <> Header.Width) or (H <> Header.Height);
if Stretch then FactorX := W / Header.Width else FactorX := 1;
if Stretch then FactorY := H / Header.Height else FactorY := 1;
{Obtain number of bytes for each row}
BytesPerRowAlpha := Header.Width;
BytesPerRowDest := (((32 * W) + 31) and not 31) div 8; {Number of bytes for each image row in destination}
BytesPerRowSrc := (((Header.BitmapInfo.bmiHeader.biBitCount * Header.Width) +
31) and not 31) div 8; {Number of bytes for each image row in source}
{Obtains image pointers}
ImageData := aBMP.ScanLine[0];
AlphaSource := Header.ImageAlpha;
Longint(ImageSource) := Longint(Header.ImageData) +
Header.BytesPerRow * Longint(Header.Height - 1);
ImageSourceOrg := ImageSource;
case Header.BitmapInfo.bmiHeader.biBitCount of
{R, G, B images}
24:
FOR j := 1 TO H DO
begin
{Process all the pixels in this line}
FOR i := 0 TO W - 1 DO
begin
if Stretch then i2 := trunc(i / FactorX) else i2 := i;
pRGBTriple(@ImageData[i])^ := pRGBTriple(@ImageSource[i2 * 3])^;
ImageData[i].rgbReserved := AlphaSource[i2];
end;
{Move pointers}
Dec(Longint(ImageData), BytesPerRowDest);
if Stretch then j2 := trunc(j / FactorY) else j2 := j;
Longint(ImageSource) := Longint(ImageSourceOrg) - BytesPerRowSrc * j2;
Longint(AlphaSource) := Longint(Header.ImageAlpha) + BytesPerRowAlpha * j2;
end;
{Palette images with 1 byte for each pixel}
1,4,8: if Header.ColorType = COLOR_GRAYSCALEALPHA then
FOR j := 1 TO H DO
begin
{Process all the pixels in this line}
FOR i := 0 TO W - 1 DO
with ImageData[i], Header.BitmapInfo do begin
if Stretch then i2 := trunc(i / FactorX) else i2 := i;
rgbRed := ImageSource[i2];
rgbGreen := ImageSource[i2];
rgbBlue := ImageSource[i2];
rgbReserved := AlphaSource[i2];
end;
{Move pointers}
Longint(ImageData) := Longint(ImageData) - BytesPerRowDest;
if Stretch then j2 := trunc(j / FactorY) else j2 := j;
Longint(ImageSource) := Longint(ImageSourceOrg) - BytesPerRowSrc * j2;
Longint(AlphaSource) := Longint(Header.ImageAlpha) +
BytesPerRowAlpha * j2;
end
else {Palette images}
begin//******************
{Obtain pointer to the transparency chunk}
TransparencyChunk := TChunktRNS(aPNGImage.Chunks.ItemFromClass(TChunktRNS));
PaletteChunk := TChunkPLTE(aPNGImage.Chunks.ItemFromClass(TChunkPLTE));
FOR j := 1 TO H DO
begin
{Process all the pixels in this line}
i := 0;
repeat
CurBit := 0;
if Stretch then i2 := trunc(i / FactorX) else i2 := i;
Data := @ImageSource[i2];
repeat
{Obtains the palette index}
case Header.BitDepth of
1: PaletteIndex := (Data^ shr (7-(I Mod 8))) and 1;
2,4: PaletteIndex := (Data^ shr ((1-(I Mod 2))*4)) and $0F;
else PaletteIndex := Data^;
end;
{Updates the image with the new pixel}
with ImageData[i] do
begin
rgbReserved := TransparencyChunk.PaletteValues[PaletteIndex];
rgbRed := PaletteChunk.Item[PaletteIndex].rgbRed;
rgbGreen := PaletteChunk.Item[PaletteIndex].rgbGreen;
rgbBlue := PaletteChunk.Item[PaletteIndex].rgbBlue;
end;
{Move to next data}
inc(i); inc(CurBit, Header.BitmapInfo.bmiHeader.biBitCount);
until CurBit >= 8;
until i >= Integer(W);
{Move pointers ********}
Longint(ImageData) := Longint(ImageData) - BytesPerRowDest;
if Stretch then j2 := trunc(j / FactorY) else j2 := j;
Longint(ImageSource) := Longint(ImageSourceOrg) - BytesPerRowSrc * j2;
end
end {Palette images **********}
end {case Header.BitmapInfo.bmiHeader.biBitCount};
end;
end. |
Répondre avec citation
Envoyé par NicCo
Partager