diff options
Diffstat (limited to 'converter/other/pnmtopng.c')
| -rw-r--r-- | converter/other/pnmtopng.c | 60 |
1 files changed, 31 insertions, 29 deletions
diff --git a/converter/other/pnmtopng.c b/converter/other/pnmtopng.c index 4e267b99..a26de835 100644 --- a/converter/other/pnmtopng.c +++ b/converter/other/pnmtopng.c @@ -1169,13 +1169,13 @@ computeUnsortedAlphaPalette(FILE * const ifP, xelval const maxval, int const format, pm_filepos const rasterPos, - gray ** const alpha_mask, + gray ** const alphaMask, unsigned int const maxPaletteEntries, colorhist_vector const chv, int const colors, - gray * alphas_of_color[], - unsigned int alphas_first_index[], - unsigned int alphas_of_color_cnt[]) { + gray * alphasOfColor[], + unsigned int alphasFirstIndex[], + unsigned int alphasOfColorCnt[]) { /*---------------------------------------------------------------------------- Read the image at position 'rasterPos' in file *ifP, which is a PNM described by 'cols', 'rows', 'maxval', and 'format'. @@ -1189,59 +1189,59 @@ computeUnsortedAlphaPalette(FILE * const ifP, actual palette is an array with up to 'maxPaletteEntries elements. Each array element contains a color index from the color palette and an alpha value. All the elements with the same color index are - contiguous. alphas_first_index[x] is the index in the + contiguous. alphasFirstIndex[x] is the index in the alpha/color palette of the first element that has color index x. - alphas_of_color_cnt[x] is the number of elements that have color - index x. alphas_of_color[x][y] is the yth alpha value that + alphasOfColorCnt[x] is the number of elements that have color + index x. alphasOfColor[x][y] is the yth alpha value that appears with color index x (in order of appearance). - alpha_color_pair_count is the total number of elements, i.e. the - total number of combinations color and alpha. + alphaColorPairCount is the total number of elements, i.e. the + total number of combinations of color and alpha. -----------------------------------------------------------------------------*/ colorhash_table cht; - int color_index; + int colorIndex; int row; xel * xelrow; cht = ppm_colorhisttocolorhash (chv, colors); - for (color_index = 0 ; color_index < colors + 1 ; ++color_index) { + for (colorIndex = 0; colorIndex < colors + 1; ++colorIndex) { /* TODO: It sure would be nice if we didn't have to allocate 256 words here for what is normally only 0 or 1 different alpha values! Maybe we should do some sophisticated reallocation. */ - MALLOCARRAY(alphas_of_color[color_index], maxPaletteEntries); - if (alphas_of_color[color_index] == NULL) - pm_error ("out of memory allocating alpha/palette entries"); - alphas_of_color_cnt[color_index] = 0; + MALLOCARRAY(alphasOfColor[colorIndex], maxPaletteEntries); + if (alphasOfColor[colorIndex] == NULL) + pm_error ("out of memory allocating alpha/color palette entries"); + alphasOfColorCnt[colorIndex] = 0; } pm_seek2(ifP, &rasterPos, sizeof(rasterPos)); xelrow = pnm_allocrow(cols); - for (row = 0 ; row < rows ; ++row) { - int col; + for (row = 0; row < rows; ++row) { + unsigned int col; pnm_readpnmrow(ifP, xelrow, cols, maxval, format); pnm_promoteformatrow(xelrow, cols, maxval, format, maxval, PPM_TYPE); - for (col = 0 ; col < cols ; ++col) { - int i; + for (col = 0; col < cols; ++col) { + unsigned int i; int const color = ppm_lookupcolor(cht, &xelrow[col]); - for (i = 0 ; i < alphas_of_color_cnt[color] ; ++i) { - if (alpha_mask[row][col] == alphas_of_color[color][i]) + for (i = 0 ; i < alphasOfColorCnt[color] ; ++i) { + if (alphaMask[row][col] == alphasOfColor[color][i]) break; } - if (i == alphas_of_color_cnt[color]) { - alphas_of_color[color][i] = alpha_mask[row][col]; - alphas_of_color_cnt[color]++; + if (i == alphasOfColorCnt[color]) { + alphasOfColor[color][i] = alphaMask[row][col]; + ++alphasOfColorCnt[color]; } } } { - int i; - alphas_first_index[0] = 0; - for (i = 1 ; i < colors ; i++) - alphas_first_index[i] = alphas_first_index[i-1] + - alphas_of_color_cnt[i-1]; + unsigned int i; + alphasFirstIndex[0] = 0; + for (i = 1; i < colors; ++i) + alphasFirstIndex[i] = alphasFirstIndex[i-1] + + alphasOfColorCnt[i-1]; } pnm_freerow(xelrow); ppm_freecolorhash(cht); @@ -1259,6 +1259,8 @@ sortAlphaPalette(gray *alphas_of_color[], /*---------------------------------------------------------------------------- Remap the palette indices so opaque entries are last. + This is _not_ a sort in place -- we do not modify our inputs. + alphas_of_color[], alphas_first_index[], and alphas_of_color_cnt[] describe an unsorted PNG (alpha/color) palette. We generate mapping[] such that mapping[x] is the index into the sorted PNG |