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trunk/third/libart_lgpl/art_rgb_bitmap_affine.c
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1 | /* Libart_LGPL - library of basic graphic primitives |

2 | * Copyright (C) 1998 Raph Levien |

3 | * |

4 | * This library is free software; you can redistribute it and/or |

5 | * modify it under the terms of the GNU Library General Public |

6 | * License as published by the Free Software Foundation; either |

7 | * version 2 of the License, or (at your option) any later version. |

8 | * |

9 | * This library is distributed in the hope that it will be useful, |

10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |

11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |

12 | * Library General Public License for more details. |

13 | * |

14 | * You should have received a copy of the GNU Library General Public |

15 | * License along with this library; if not, write to the |

16 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |

17 | * Boston, MA 02111-1307, USA. |

18 | */ |

19 | |

20 | #include "config.h" |

21 | #include "art_rgb_bitmap_affine.h" |

22 | |

23 | #include <math.h> |

24 | #include "art_misc.h" |

25 | #include "art_point.h" |

26 | #include "art_affine.h" |

27 | #include "art_rgb_affine_private.h" |

28 | |

29 | /* This module handles compositing of affine-transformed bitmap images |

30 | over rgb pixel buffers. */ |

31 | |

32 | /* Composite the source image over the destination image, applying the |

33 | affine transform. Foreground color is given and assumed to be |

34 | opaque, background color is assumed to be fully transparent. */ |

35 | |

36 | static void |

37 | art_rgb_bitmap_affine_opaque (art_u8 *dst, |

38 | int x0, int y0, int x1, int y1, |

39 | int dst_rowstride, |

40 | const art_u8 *src, |

41 | int src_width, int src_height, int src_rowstride, |

42 | art_u32 rgb, |

43 | const double affine[6], |

44 | ArtFilterLevel level, |

45 | ArtAlphaGamma *alphagamma) |

46 | { |

47 | /* Note: this is a slow implementation, and is missing all filter |

48 | levels other than NEAREST. It is here for clarity of presentation |

49 | and to establish the interface. */ |

50 | int x, y; |

51 | double inv[6]; |

52 | art_u8 *dst_p, *dst_linestart; |

53 | const art_u8 *src_p; |

54 | ArtPoint pt, src_pt; |

55 | int src_x, src_y; |

56 | art_u8 r, g, b; |

57 | int run_x0, run_x1; |

58 | |

59 | r = rgb >> 16; |

60 | g = (rgb >> 8) & 0xff; |

61 | b = rgb & 0xff; |

62 | dst_linestart = dst; |

63 | art_affine_invert (inv, affine); |

64 | for (y = y0; y < y1; y++) |

65 | { |

66 | pt.y = y + 0.5; |

67 | run_x0 = x0; |

68 | run_x1 = x1; |

69 | art_rgb_affine_run (&run_x0, &run_x1, y, src_width, src_height, |

70 | inv); |

71 | dst_p = dst_linestart + (run_x0 - x0) * 3; |

72 | for (x = run_x0; x < run_x1; x++) |

73 | { |

74 | pt.x = x + 0.5; |

75 | art_affine_point (&src_pt, &pt, inv); |

76 | src_x = floor (src_pt.x); |

77 | src_y = floor (src_pt.y); |

78 | src_p = src + (src_y * src_rowstride) + (src_x >> 3); |

79 | if (*src_p & (128 >> (src_x & 7))) |

80 | { |

81 | dst_p[0] = r; |

82 | dst_p[1] = g; |

83 | dst_p[2] = b; |

84 | } |

85 | dst_p += 3; |

86 | } |

87 | dst_linestart += dst_rowstride; |

88 | } |

89 | } |

90 | /* Composite the source image over the destination image, applying the |

91 | affine transform. Foreground color is given, background color is |

92 | assumed to be fully transparent. */ |

93 | |

94 | /** |

95 | * art_rgb_bitmap_affine: Affine transform source bitmap image and composite. |

96 | * @dst: Destination image RGB buffer. |

97 | * @x0: Left coordinate of destination rectangle. |

98 | * @y0: Top coordinate of destination rectangle. |

99 | * @x1: Right coordinate of destination rectangle. |

100 | * @y1: Bottom coordinate of destination rectangle. |

101 | * @dst_rowstride: Rowstride of @dst buffer. |

102 | * @src: Source image bitmap buffer. |

103 | * @src_width: Width of source image. |

104 | * @src_height: Height of source image. |

105 | * @src_rowstride: Rowstride of @src buffer. |

106 | * @rgba: RGBA foreground color, in 0xRRGGBBAA. |

107 | * @affine: Affine transform. |

108 | * @level: Filter level. |

109 | * @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing. |

110 | * |

111 | * Affine transform the source image stored in @src, compositing over |

112 | * the area of destination image @dst specified by the rectangle |

113 | * (@x0, @y0) - (@x1, @y1). |

114 | * |

115 | * The source bitmap stored with MSB as the leftmost pixel. Source 1 |

116 | * bits correspond to the semitransparent color @rgba, while source 0 |

117 | * bits are transparent. |

118 | * |

119 | * See art_rgb_affine() for a description of additional parameters. |

120 | **/ |

121 | void |

122 | art_rgb_bitmap_affine (art_u8 *dst, |

123 | int x0, int y0, int x1, int y1, int dst_rowstride, |

124 | const art_u8 *src, |

125 | int src_width, int src_height, int src_rowstride, |

126 | art_u32 rgba, |

127 | const double affine[6], |

128 | ArtFilterLevel level, |

129 | ArtAlphaGamma *alphagamma) |

130 | { |

131 | /* Note: this is a slow implementation, and is missing all filter |

132 | levels other than NEAREST. It is here for clarity of presentation |

133 | and to establish the interface. */ |

134 | int x, y; |

135 | double inv[6]; |

136 | art_u8 *dst_p, *dst_linestart; |

137 | const art_u8 *src_p; |

138 | ArtPoint pt, src_pt; |

139 | int src_x, src_y; |

140 | int alpha; |

141 | art_u8 bg_r, bg_g, bg_b; |

142 | art_u8 fg_r, fg_g, fg_b; |

143 | art_u8 r, g, b; |

144 | int run_x0, run_x1; |

145 | |

146 | alpha = rgba & 0xff; |

147 | if (alpha == 0xff) |

148 | { |

149 | art_rgb_bitmap_affine_opaque (dst, x0, y0, x1, y1, dst_rowstride, |

150 | src, |

151 | src_width, src_height, src_rowstride, |

152 | rgba >> 8, |

153 | affine, |

154 | level, |

155 | alphagamma); |

156 | return; |

157 | } |

158 | /* alpha = (65536 * alpha) / 255; */ |

159 | alpha = (alpha << 8) + alpha + (alpha >> 7); |

160 | r = rgba >> 24; |

161 | g = (rgba >> 16) & 0xff; |

162 | b = (rgba >> 8) & 0xff; |

163 | dst_linestart = dst; |

164 | art_affine_invert (inv, affine); |

165 | for (y = y0; y < y1; y++) |

166 | { |

167 | pt.y = y + 0.5; |

168 | run_x0 = x0; |

169 | run_x1 = x1; |

170 | art_rgb_affine_run (&run_x0, &run_x1, y, src_width, src_height, |

171 | inv); |

172 | dst_p = dst_linestart + (run_x0 - x0) * 3; |

173 | for (x = run_x0; x < run_x1; x++) |

174 | { |

175 | pt.x = x + 0.5; |

176 | art_affine_point (&src_pt, &pt, inv); |

177 | src_x = floor (src_pt.x); |

178 | src_y = floor (src_pt.y); |

179 | src_p = src + (src_y * src_rowstride) + (src_x >> 3); |

180 | if (*src_p & (128 >> (src_x & 7))) |

181 | { |

182 | bg_r = dst_p[0]; |

183 | bg_g = dst_p[1]; |

184 | bg_b = dst_p[2]; |

185 | |

186 | fg_r = bg_r + (((r - bg_r) * alpha + 0x8000) >> 16); |

187 | fg_g = bg_g + (((g - bg_g) * alpha + 0x8000) >> 16); |

188 | fg_b = bg_b + (((b - bg_b) * alpha + 0x8000) >> 16); |

189 | |

190 | dst_p[0] = fg_r; |

191 | dst_p[1] = fg_g; |

192 | dst_p[2] = fg_b; |

193 | } |

194 | dst_p += 3; |

195 | } |

196 | dst_linestart += dst_rowstride; |

197 | } |

198 | } |

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