Merge branch 'master' of git://git.ucc.asn.au/tpg/acess2

[tpg/acess2.git] / Usermode / Applications / axwin4_src / Server / include / CColour.hpp

diff --git a/Usermode/Applications/axwin4_src/Server/include/CColour.hpp b/Usermode/Applications/axwin4_src/Server/include/CColour.hpp
new file mode 100644 (file)
index 0000000..d47d7e0
--- /dev/null
+++ b/Usermode/Applications/axwin4_src/Server/include/CColour.hpp
@@ -0,0 +1,93 @@
+/*
+ * Acess2 GUI v4
+ * - By John Hodge (thePowersGang)
+ *
+ * CColour.hpp
+ * - Generic colour handling and blending
+ */
+#ifndef _CCOLOUR_HPP_
+#define _CCOLOUR_HPP_
+
+namespace AxWin {
+
+class CColour
+{
+       static const uint8_t    uint8_max = 0xFF;
+       static const unsigned int comp_max = 0x7FFF;
+       
+       unsigned int    m_alpha;
+       unsigned int    m_red;
+       unsigned int    m_green;
+       unsigned int    m_blue;
+
+private:
+       static unsigned int u8_to_ui(uint8_t u8v) {
+               return (unsigned int)u8v * comp_max / uint8_max;
+       }
+       static uint8_t ui_to_u8(unsigned int uiv) {
+               return uiv * uint8_max / comp_max;
+       }
+       // Perform an alpha-based blend on two components
+       static unsigned int alpha_blend(unsigned int alpha_comp, unsigned int left, unsigned int right) {
+               return (left * (comp_max - alpha_comp) + right * alpha_comp) / comp_max;
+       }
+       // Float values:
+       // - infinity == saturation, 1 == nothing
+       // fv = MAX / (MAX - uiv)
+       static float ui_to_float(unsigned int uiv) {
+               return (float)comp_max / (comp_max - uiv);
+       }
+       // uiv = MAX - MAX / fv
+       static unsigned int float_to_ui(float fv) {
+               return comp_max - comp_max / fv;
+       }
+       // perform a non-oversaturating blend of two colours (using an inverse relationship)
+       static unsigned int add_blend(unsigned int a, unsigned int b) {
+               return float_to_ui( ui_to_float(a) + ui_to_float(b) );
+       }
+
+       CColour(unsigned int r, unsigned int g, unsigned int b, unsigned int a):
+               m_alpha(a), m_red(r), m_green(g), m_blue(b)
+       {
+       }
+public:
+
+       static CColour from_argb(uint32_t val) {
+               return CColour(
+                       u8_to_ui((val>>16) & 0xFF),
+                       u8_to_ui((val>> 8) & 0xFF),
+                       u8_to_ui((val>> 0) & 0xFF),
+                       u8_to_ui((val>>24) & 0xFF)
+                       );
+       }
+       
+       uint32_t to_argb() const {
+               uint32_t        rv = 0;
+               rv |= (uint32_t)ui_to_u8(m_red)   << 16;
+               rv |= (uint32_t)ui_to_u8(m_green) <<  8;
+               rv |= (uint32_t)ui_to_u8(m_blue)  <<  0;
+               rv |= (uint32_t)ui_to_u8(m_alpha) << 24;
+               return rv;
+       }
+       
+       // performs a blend of the two colours, maintaining the target alpha, using the source alpha as the blend control
+       CColour& blend(const CColour& other) {
+               m_red   = alpha_blend(other.m_alpha, m_red  , other.m_red  );
+               m_green = alpha_blend(other.m_alpha, m_green, other.m_green);
+               m_blue  = alpha_blend(other.m_alpha, m_blue , other.m_blue );
+               return *this;
+       }
+       // Add all components
+       CColour& operator+(const CColour& other) {
+               m_alpha = add_blend(m_alpha, other.m_alpha);
+               m_red   = add_blend(m_red  , other.m_red  );
+               m_green = add_blend(m_green, other.m_green);
+               m_blue  = add_blend(m_blue , other.m_blue );
+               return *this;
+       }
+};
+
+}      // namespace AxWin
+
+#endif
+