#include <bmanip.h>
Public Member Functions | |
| BOOL | ApplyGaussianFilter (BYTE *bits, INT32 wid, INT32 hei, INT32 matrix[3][3], BOOL IgnoreBlankPixels=FALSE) |
| Applies a 3x3 matrix to the bitmap's alpha channel. | |
Definition at line 124 of file bmanip.h.
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Applies a 3x3 matrix to the bitmap's alpha channel.
Definition at line 124 of file bmanip.cpp. 00126 { 00127 // we need a temporary bitmap 00128 INT32 ksize = (wid) * (hei) * 4; 00129 00130 BYTE * tmpBits = new BYTE[ksize]; 00131 00132 if (!tmpBits) 00133 return FALSE; 00134 00135 memcpy(tmpBits, bits, ksize); 00136 00137 INT32 size = wid * hei; 00138 size -= wid * 2; 00139 size -= 2; 00140 00141 COLORREF *srcPtr = ((COLORREF *)bits); 00142 COLORREF *destPtr = ((COLORREF *)tmpBits) + wid + 1; 00143 00144 UINT32 srcAlpha = 0; 00145 UINT32 destAlpha = 0; 00146 00147 INT32 incBy1 = wid*4; 00148 00149 INT32 sum = 0; 00150 00151 INT32 posX = 0; 00152 INT32 posY = 1; 00153 00154 COLORREF Area[3][3]; 00155 00156 INT32 i = 0; 00157 INT32 j = 0; 00158 00159 BYTE R = 0; 00160 BYTE A = 0; 00161 00162 INT32 SumR; 00163 INT32 SumA; 00164 00165 while (posY < hei - 1) 00166 { 00167 // transfer colour 00168 for (i = 0 ; i < 3; i++) 00169 { 00170 for (j = 0 ; j < 3; j++) 00171 { 00172 Area[i][j] = *(srcPtr + i * wid + j); 00173 } 00174 } 00175 00176 // now, ignore transparent areas 00177 if (((Area[1][1] & 0xff000000) >> 24) != 0xff || !bIgnoreBlankPixels) 00178 { 00179 SumR = 0; 00180 SumA = 0; 00181 sum = 0; 00182 00183 for (i = 0 ; i < 3; i++) 00184 { 00185 for (j = 0 ; j < 3; j++) 00186 { 00187 A = (BYTE)(Area[i][j] & 0xff000000) >> 24; 00188 R = (BYTE)(Area[i][j] & 0xff); 00189 00190 if (A != 0xff || !bIgnoreBlankPixels) 00191 { 00192 SumR += ((INT32)R) * matrix[i][j]; 00193 SumA += ((INT32)A) * matrix[i][j]; 00194 sum += matrix[i][j]; 00195 } 00196 } 00197 } 00198 00199 SumR /= sum; 00200 SumA /= sum; 00201 00202 *destPtr = SumR + (SumR << 8) + (SumR << 16) + (SumA << 24); 00203 } 00204 00205 // increment of pointers 00206 posX ++; 00207 00208 destPtr ++; 00209 srcPtr ++; 00210 00211 if (posX >= wid - 3) 00212 { 00213 destPtr += 3; 00214 srcPtr += 3; 00215 posX = 0; 00216 posY ++; 00217 } 00218 } 00219 00220 memcpy(bits, tmpBits, wid * hei * 4); 00221 00222 delete [] tmpBits; 00223 00224 return TRUE; 00225 }
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1.4.4