void SkTMaskGamma_build_correcting_lut(uint8_t table[256], U8CPU srcI, SkScalar contrast,
const SkColorSpaceLuminance& srcConvert, SkScalar srcGamma,
const SkColorSpaceLuminance& dstConvert, SkScalar dstGamma) {
const float src = (float)srcI / 255.0f;
const float linSrc = srcConvert.toLuma(srcGamma, src);
//Guess at the dst. The perceptual inverse provides smaller visual
//discontinuities when slight changes to desaturated colors cause a channel
//to map to a different correcting lut with neighboring srcI.
//See https://code.google.com/p/chromium/issues/detail?id=141425#c59 .
const float dst = 1.0f - src;
const float linDst = dstConvert.toLuma(dstGamma, dst);
//Contrast value tapers off to 0 as the src luminance becomes white
const float adjustedContrast = SkScalarToFloat(contrast) * linDst;
//Remove discontinuity and instability when src is close to dst.
//The value 1/256 is arbitrary and appears to contain the instability.
if (fabs(src - dst) < (1.0f / 256.0f)) {
float ii = 0.0f;
for (int i = 0; i < 256; ++i, ii += 1.0f) {
float rawSrca = ii / 255.0f;
float srca = apply_contrast(rawSrca, adjustedContrast);
table[i] = SkToU8(sk_float_round2int(255.0f * srca));
}
} else {
// Avoid slow int to float conversion.
float ii = 0.0f;
for (int i = 0; i < 256; ++i, ii += 1.0f) {
// 'rawSrca += 1.0f / 255.0f' and even
// 'rawSrca = i * (1.0f / 255.0f)' can add up to more than 1.0f.
// When this happens the table[255] == 0x0 instead of 0xff.
// See http://code.google.com/p/chromium/issues/detail?id=146466
float rawSrca = ii / 255.0f;
float srca = apply_contrast(rawSrca, adjustedContrast);
SkASSERT(srca <= 1.0f);
float dsta = 1.0f - srca;
//Calculate the output we want.
float linOut = (linSrc * srca + dsta * linDst);
SkASSERT(linOut <= 1.0f);
float out = dstConvert.fromLuma(dstGamma, linOut);
//Undo what the blit blend will do.
float result = (out - dst) / (src - dst);
SkASSERT(sk_float_round2int(255.0f * result) <= 255);
table[i] = SkToU8(sk_float_round2int(255.0f * result));
}
}
}
unsigned int filter_color(unsigned int color, t_opt *opt)
{
if (opt->filter == 1)
color = filter_sepia(color);
if (opt->filter == 2)
color = filter_grey(color);
if (opt->gamma != -1)
color = gamma_filter(color, opt->gamma);
if (opt->filter == 3)
color = revers_filter(color, opt);
if (opt->contrast != 1.0)
color = apply_contrast(color, opt);
if (opt->saturation != 1.0)
color = saturation(color, opt->saturation);
return (color);
}
int main( int argc , char ** argv )
{
printf( "Starting up VoidEye test.\n" );
init_test( "" );
update_texture();
remove_colours();
update_texture();
int b , d , a;
b = find_brightest();
d = find_darkest();
a = find_avarage();
printf( "b: %d d: %d a: %d\n", b , d , a );
apply_contrast( 256 );
update_texture();
create_groups();
return 0;
}
