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New raster colorizer modes linear-rgba and linear-bgra

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This commit is contained in:
Jiri Drbalek 2019-05-16 22:54:14 +02:00
parent ac19076f0b
commit a74543a145
2 changed files with 34 additions and 1 deletions
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4
include/mapnik/raster_colorizer.hpp
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@ -61,9 +61,11 @@ class raster;
enum colorizer_mode_enum : std::uint8_t
{
COLORIZER_INHERIT = 0, //!< The stop inherits the mode from the colorizer
COLORIZER_LINEAR = 1, //!< Linear interpolation between colors
COLORIZER_LINEAR = 1, //!< Linear interpolation between colors, each channel separately
COLORIZER_DISCRETE = 2, //!< Single color for stop
COLORIZER_EXACT = 3, //!< Only the exact value specified for the stop gets translated, others use the default
COLORIZER_LINEAR_RGBA = 4,//!< Linear interpolation between colors, all channels combined as RGBA value
COLORIZER_LINEAR_BGRA = 5,//!< Linear interpolation between colors, all channels combined as BGRA value
colorizer_mode_enum_MAX
};

31
src/raster_colorizer.cpp
View file

@ -42,6 +42,8 @@ static const char *colorizer_mode_strings[] = {
"linear",
"discrete",
"exact",
"linear-rgba",
"linear-bgra",
""
};
@ -257,6 +259,35 @@ unsigned raster_colorizer::get_color(float val) const
}
break;
case COLORIZER_LINEAR_RGBA:
{
if(nextStopValue == stopValue)
{
return stopColor.rgba();
}
double fraction = (val - stopValue) / (nextStopValue - stopValue);
double colorStart = static_cast<double>(stopColor.rgba());
double colorEnd = static_cast<double>(nextStopColor.rgba());
outputColor = color(colorStart + fraction * (colorEnd - colorStart));
}
break;
case COLORIZER_LINEAR_BGRA:
{
if(nextStopValue == stopValue)
{
return stopColor.rgba();
}
double fraction = (val - stopValue) / (nextStopValue - stopValue);
std::swap(stopColor.red_, stopColor.blue_);
std::swap(nextStopColor.red_, nextStopColor.blue_);
double colorStart = static_cast<double>(stopColor.rgba());
double colorEnd = static_cast<double>(nextStopColor.rgba());
outputColor = color(colorStart + fraction * (colorEnd - colorStart));
std::swap(outputColor.red_, outputColor.blue_);
}
break;
case COLORIZER_DISCRETE:
outputColor = stopColor;
break;