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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 03:13:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 03:13:10 +0000 |
commit | 3c57dd931145d43f2b0aef96c4d178135956bf91 (patch) | |
tree | 3de698981e9f0cc2c4f9569b19a5f3595e741f6b /plug-ins/file-dds/mktables.c | |
parent | Initial commit. (diff) | |
download | gimp-3c57dd931145d43f2b0aef96c4d178135956bf91.tar.xz gimp-3c57dd931145d43f2b0aef96c4d178135956bf91.zip |
Adding upstream version 2.10.36.upstream/2.10.36
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'plug-ins/file-dds/mktables.c')
-rw-r--r-- | plug-ins/file-dds/mktables.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/plug-ins/file-dds/mktables.c b/plug-ins/file-dds/mktables.c new file mode 100644 index 0000000..99eef6d --- /dev/null +++ b/plug-ins/file-dds/mktables.c @@ -0,0 +1,130 @@ +#include <stdlib.h> +#include <stdio.h> + +static int mul8bit(int a, int b) +{ + int t = a * b + 128; + return((t + (t >> 8)) >> 8); +} + +static int lerp13(int a, int b) +{ +#if 0 + return(a + mul8bit(b - a, 0x55)); +#else + return((2 * a + b) / 3); +#endif +} + +static void prepare_opt_table(unsigned char *tab, + const unsigned char *expand, int size) +{ + int i, mn, mx, bestE, minE, maxE, e; + + for(i = 0; i < 256; ++i) + { + bestE = 256 * 100; + + for(mn = 0; mn < size; ++mn) + { + for(mx = 0; mx < size; ++mx) + { + minE = expand[mn]; + maxE = expand[mx]; + e = abs(lerp13(maxE, minE) - i) * 100; + + e += abs(mx - mn) * 3; + + if(e < bestE) + { + tab[i * 2 + 0] = mx; + tab[i * 2 + 1] = mn; + bestE = e; + } + } + } + } +} + +#if 0 +int main(void) +{ + FILE *fp; + int i, v; + unsigned char expand5[32]; + unsigned char expand6[64]; + unsigned char quantRB[256 + 16]; + unsigned char quantG[256 + 16]; + unsigned char omatch5[256][2]; + unsigned char omatch6[256][2]; + + fp = fopen("dxt_tables.h", "w"); + fprintf(fp, + "#ifndef DXT_TABLES_H\n" + "#define DXT_TABLES_H\n\n"); + + for(i = 0; i < 32; ++i) + expand5[i] = (i << 3) | (i >> 2); + + for(i = 0; i < 64; ++i) + expand6[i] = (i << 2) | (i >> 4); + + for(i = 0; i < 256 + 16; ++i) + { + v = i - 8; + if(v < 0) v = 0; + if(v > 255) v = 255; + quantRB[i] = expand5[mul8bit(v, 31)]; + quantG[i] = expand6[mul8bit(v, 63)]; + } + + fprintf(fp, + "static const unsigned char quantRB[256 + 16] =\n" + "{"); + for(i = 0; i < 256 + 16; ++i) + { + if(i % 8 == 0) fprintf(fp, "\n "); + fprintf(fp, "0x%02x, ", quantRB[i]); + } + fprintf(fp, "\n};\n\n"); + + fprintf(fp, + "static const unsigned char quantG[256 + 16] =\n" + "{"); + for(i = 0; i < 256 + 16; ++i) + { + if(i % 8 == 0) fprintf(fp, "\n "); + fprintf(fp, "0x%02x, ", quantG[i]); + } + fprintf(fp, "\n};\n\n"); + + prepare_opt_table(&omatch5[0][0], expand5, 32); + prepare_opt_table(&omatch6[0][0], expand6, 64); + + fprintf(fp, + "static const unsigned char omatch5[256][2] =\n" + "{"); + for(i = 0; i < 256; ++i) + { + if(i % 4 == 0) fprintf(fp, "\n "); + fprintf(fp, "{0x%02x, 0x%02x}, ", omatch5[i][0], omatch5[i][1]); + } + fprintf(fp, "\n};\n\n"); + + fprintf(fp, + "static const unsigned char omatch6[256][2] =\n" + "{"); + for(i = 0; i < 256; ++i) + { + if(i % 4 == 0) fprintf(fp, "\n "); + fprintf(fp, "{0x%02x, 0x%02x}, ", omatch6[i][0], omatch6[i][1]); + } + fprintf(fp, "\n};\n\n"); + + fprintf(fp, "#endif\n"); + + fclose(fp); + + return(0); +} +#endif |