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AG_COLOR(3) Library Functions Manual AG_COLOR(3) NAME AG_Color -- agar color structure SYNOPSIS #include <agar/core.h> #include <agar/gui.h> DESCRIPTION The AG_Color structure describes a color in terms of Red, Green, Blue, and Alpha components. The AG_Color structure is declared as: typedef struct ag_color { #if AG_MODEL == AG_LARGE Uint16 r,g,b,a; /* LG (16-bit color) */ #else Uint8 r,g,b,a; /* MD (8-bit color) */ #endif } AG_Color; The alpha component may or may not be used in a given context. A value of 0 (or AG_TRANSPARENT or AG_COLOR_FIRST) is fully transparent, while AG_OPAQUE (or AG_COLOR_LAST) is fully opaque. INTERFACE void AG_ColorRGB_8(AG_Color *c, Uint8 r, Uint8 g, Uint8 b) void AG_ColorRGBA_8(AG_Color *c, Uint8 r, Uint8 g, Uint8 b, Uint8 a) void AG_ColorRGB_16(AG_Color *c, Uint16 r, Uint16 g, Uint16 b) void AG_ColorRGBA_16(AG_Color *c, Uint16 r, Uint16 g, Uint16 b, Uint16 a) void AG_HSV2Color(float hue, float sat, float val, AG_Color *c) void AG_Color2HSV(AG_Color *c, float *hue, float *sat, float *val) void AG_ColorHex16(AG_Color *c, Uint16 hex) void AG_ColorHex32(AG_Color *c, Uint32 hex) void AG_ColorHex64(AG_Color *c, Uint64 hex) void AG_ColorFromString(AG_Color *c, const char *spec, const AG_Color *parentColor) void AG_ColorNone(AG_Color *c) void AG_ColorBlack(AG_Color *c) void AG_ColorWhite(AG_Color *c) void AG_ColorLighten(AG_Color *c, int shade) void AG_ColorDarken(AG_Color *c, int shade) void AG_ColorInterpolate(AG_Color *cx, const AG_Color *c1, const AG_Color *c2) int AG_ColorCompare(const AG_Color *a, const AG_Color *b) AG_ColorRGB_8() and AG_ColorRGB_16() return an AG_Color from 8- or 16-bit red, green and blue components (with alpha set to fully opaque). AG_ColorRGBA_8() and AG_ColorRGBA_16() return an AG_Color from 8- or 16-bit RGB and alpha components. AG_HSV2Color() maps a color in HSV space to the closest approximation in RGB space, and copies the A component as-is. The inverse operation is performed by AG_Color2HSV(). Note: H and V become increasingly lossy as S->0. The AG_ColorHex16(), AG_ColorHex32() and AG_ColorHex64() routines con- vert a color packed into 0xRGBA (4-bit components), 0xRRGGBBAA (8-bit components), or 0xRRRRGGGGBBBBAAAA (16-bit components) into an AG_Color. AG_ColorFromString() converts a text-based color representation to an AG_Color. The following formats are allowed: "#RGB[A]" "#RRGGBB[AA]" "#RRRRGGGGBBBB[AAAA]" "r,g,b[,a]" "rgb(r,g,b[,a])" "rgb16(r,g,b[,a])" "hsv(h,s,v[,a])" "AliceBlue" Color components may be separated by `/', ':' or ','. A component terminating with a `%' character is interpreted as a ratio (in %) of the corresponding component of pColor (or White if pColor is NULL). AG_ColorNone() initializes the color to fully transparent black (0,0,0,0). AG_ColorBlack() and AG_ColorWhite() initialize the respec- tive fully opaque color. AG_ColorLighten() and AG_ColorDarken increase and decrease the overall value of c by some small increment multiplied by shade. A shade argu- ment of 0 leaves the color value unchanged. AG_ColorInterpolate() traces an imaginary line in RGB color space be- tween c1 and c2 and returns into cx the color closest to the point de- scribed by the fraction num over denom. AG_ColorCompare() returns non-zero if the two colors differ. SEE ALSO AG_Intro(3), AG_MapColorRGB(3), AG_MapColorRGBA(3), AG_MapPixelRGB(3), AG_MapPixelRGBA(3), AG_Surface(3), AG_Widget(3) HISTORY Agar 1.0 through 1.3 described colors using packed pixels in a 32-bit reference format. The AG_Color structure first appeared in Agar 1.4.0. Agar 1.6.0 introduced the AG_LARGE memory model and 48-bit "Deep Color". AG_Color2HSV(), AG_HSV2Color(), AG_ColorNone(), AG_ColorDarken(), AG_ColorLighten() and the AG_ColorInterpolate() func- tions appeared in 1.6.0. Agar 1.7 December 21, 2022 AG_COLOR(3)
NAME | SYNOPSIS | DESCRIPTION | INTERFACE | SEE ALSO | HISTORY
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