/* Copyright (C) 2022 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see .
*/
#ifndef INCLUDED_COLOR
#define INCLUDED_COLOR
#include "graphics/SColor.h"
#include "maths/Vector3D.h"
#include "maths/Vector4D.h"
#include "ps/containers/Span.h"
#include "ps/CStrForward.h"
// Simple defines for 3 and 4 component floating point colors - just map to
// corresponding vector types.
typedef CVector3D RGBColor;
typedef CVector4D RGBAColor;
// Convert float RGB(A) colors to unsigned byte.
// Exposed as function pointer because it is set at init-time to
// one of several implementations depending on CPU caps.
extern SColor4ub (*ConvertRGBColorTo4ub)(const RGBColor& src);
/**
* Detects CPU caps and activates the best possible codepath.
*/
extern void ColorActivateFastImpl();
struct CColor
{
CColor() : r(-1.f), g(-1.f), b(-1.f), a(1.f) {}
CColor(float cr, float cg, float cb, float ca) : r(cr), g(cg), b(cb), a(ca) {}
/**
* Returns whether this has been set to a valid color.
*/
operator bool() const
{
return r >= 0 && g >= 0 && b >= 0 && a >= 0;
}
/**
* Try to parse @p Value as a color. Returns true on success, false otherwise.
* Leaves the color unchanged if it failed.
* @param value Should be "r g b" or "r g b a" where each value is an integer in [0,255].
* @param defaultAlpha The alpha value that is used if the format of @p Value is "r g b".
*/
bool ParseString(const CStr8& value, int defaultAlpha = 255);
bool operator==(const CColor& color) const;
bool operator!=(const CColor& color) const
{
return !(*this == color);
}
// For passing to uniform as vec3/vec4.
PS::span AsFloatArray() const
{
// Additional check to prevent a weird compiler has a different
// alignement for an array and a class members.
static_assert(
sizeof(CColor) == sizeof(float) * 4u &&
offsetof(CColor, r) == 0 &&
offsetof(CColor, g) == sizeof(float) &&
offsetof(CColor, b) == sizeof(float) * 2u &&
offsetof(CColor, a) == sizeof(float) * 3u,
"CColor should be properly layouted to use AsFloatArray");
return PS::span(&r, 4);
}
// For passing to CRenderer:
SColor4ub AsSColor4ub() const
{
return SColor4ub(
static_cast(r * 255.f),
static_cast(g * 255.f),
static_cast(b * 255.f),
static_cast(a * 255.f)
);
}
float r, g, b, a;
};
#endif // INCLUDED_COLOR