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Merge branch 'blendmodes'

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Introduces the sf::BlendMode class that supports separate blend functions and equations.
Replaces the old sf::BlendMode enum.

Further changes:
* Fixed merge conflicts resulting from GLExtensions in mobile branch
* GLExtensions: Added GLEXT_blend_equation_separate
* Added file BlendMode.cpp
* Replaced occurrences of sf::BlendMode value parameters with const-references
* Adapted rendering code in sf::RenderTarget
This commit is contained in:
Jan Haller 2014-04-26 19:36:46 +02:00
commit cdf32a7881
8 changed files with 348 additions and 54 deletions
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182
include/SFML/Graphics/BlendMode.hpp
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@ -25,22 +25,190 @@
#ifndef SFML_BLENDMODE_HPP
#define SFML_BLENDMODE_HPP
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Graphics/Export.hpp>
namespace sf
{
////////////////////////////////////////////////////////////
/// \ingroup graphics
/// \brief Available blending modes for drawing
/// \brief Blending modes for drawing
///
////////////////////////////////////////////////////////////
enum BlendMode
struct SFML_GRAPHICS_API BlendMode
{
BlendAlpha, ///< Pixel = Source * Source.a + Dest * (1 - Source.a)
BlendAdd, ///< Pixel = Source + Dest
BlendMultiply, ///< Pixel = Source * Dest
BlendNone ///< Pixel = Source
////////////////////////////////////////////////////////
/// \brief Enumeration of the blending factors
///
/// The factors are mapped directly to their OpenGL equivalents,
/// specified by glBlendFunc() or glBlendFuncSeparate().
////////////////////////////////////////////////////////
enum Factor
{
Zero, ///< (0, 0, 0, 0)
One, ///< (1, 1, 1, 1)
SrcColor, ///< (src.r, src.g, src.b, src.a)
OneMinusSrcColor, ///< (1, 1, 1, 1) - (src.r, src.g, src.b, src.a)
DstColor, ///< (dst.r, dst.g, dst.b, dst.a)
OneMinusDstColor, ///< (1, 1, 1, 1) - (dst.r, dst.g, dst.b, dst.a)
SrcAlpha, ///< (src.a, src.a, src.a, src.a)
OneMinusSrcAlpha, ///< (1, 1, 1, 1) - (src.a, src.a, src.a, src.a)
DstAlpha, ///< (dst.a, dst.a, dst.a, dst.a)
OneMinusDstAlpha ///< (1, 1, 1, 1) - (dst.a, dst.a, dst.a, dst.a)
};
////////////////////////////////////////////////////////
/// \brief Enumeration of the blending equations
///
/// The equations are mapped directly to their OpenGL equivalents,
/// specified by glBlendEquation() or glBlendEquationSeparate().
////////////////////////////////////////////////////////
enum Equation
{
Add, ///< Pixel = Src * SrcFactor + Dst * DstFactor
Subtract ///< Pixel = Src * SrcFactor - Dst * DstFactor
};
////////////////////////////////////////////////////////////
/// \brief Default constructor
///
/// Constructs a blending mode that does alpha blending.
///
////////////////////////////////////////////////////////////
BlendMode();
////////////////////////////////////////////////////////////
/// \brief Construct the blend mode given the factors and equation.
///
/// This constructor uses the same factors and equation for both
/// color and alpha components. It also defaults to the Add equation.
///
/// \param sourceFactor Specifies how to compute the source factor for the color and alpha channels.
/// \param destinationFactor Specifies how to compute the destination factor for the color and alpha channels.
/// \param blendEquation Specifies how to combine the source and destination colors and alpha.
///
////////////////////////////////////////////////////////////
BlendMode(Factor sourceFactor, Factor destinationFactor, Equation blendEquation = Add);
////////////////////////////////////////////////////////////
/// \brief Construct the blend mode given the factors and equation.
///
/// \param colorSourceFactor Specifies how to compute the source factor for the color channels.
/// \param colorDestinationFactor Specifies how to compute the destination factor for the color channels.
/// \param colorBlendEquation Specifies how to combine the source and destination colors.
/// \param alphaSourceFactor Specifies how to compute the source factor.
/// \param alphaDestinationFactor Specifies how to compute the destination factor.
/// \param alphaBlendEquation Specifies how to combine the source and destination alphas.
///
////////////////////////////////////////////////////////////
BlendMode(Factor colorSourceFactor, Factor colorDestinationFactor,
Equation colorBlendEquation, Factor alphaSourceFactor,
Factor alphaDestinationFactor, Equation alphaBlendEquation);
////////////////////////////////////////////////////////////
// Member Data
////////////////////////////////////////////////////////////
Factor colorSrcFactor; ///< Source blending factor for the color channels
Factor colorDstFactor; ///< Destination blending factor for the color channels
Equation colorEquation; ///< Blending equation for the color channels
Factor alphaSrcFactor; ///< Source blending factor for the alpha channel
Factor alphaDstFactor; ///< Destination blending factor for the alpha channel
Equation alphaEquation; ///< Blending equation for the alpha channel
};
////////////////////////////////////////////////////////////
/// \relates BlendMode
/// \brief Overload of the == operator
///
/// \param left Left operand
/// \param right Right operand
///
/// \return True if blending modes are equal, false if they are different
///
////////////////////////////////////////////////////////////
SFML_GRAPHICS_API bool operator ==(const BlendMode& left, const BlendMode& right);
////////////////////////////////////////////////////////////
/// \relates BlendMode
/// \brief Overload of the != operator
///
/// \param left Left operand
/// \param right Right operand
///
/// \return True if blending modes are different, false if they are equal
///
////////////////////////////////////////////////////////////
SFML_GRAPHICS_API bool operator !=(const BlendMode& left, const BlendMode& right);
////////////////////////////////////////////////////////////
// Commonly used blending modes
////////////////////////////////////////////////////////////
SFML_GRAPHICS_API extern const BlendMode BlendAlpha; ///< Blend source and dest according to dest alpha
SFML_GRAPHICS_API extern const BlendMode BlendAdd; ///< Add source to dest
SFML_GRAPHICS_API extern const BlendMode BlendMultiply; ///< Multiply source and dest
SFML_GRAPHICS_API extern const BlendMode BlendNone; ///< Overwrite dest with source
} // namespace sf
#endif // SFML_BLENDMODE_HPP
////////////////////////////////////////////////////////////
/// \class sf::BlendMode
/// \ingroup graphics
///
/// sf::BlendMode is a class that represents a blend mode. A blend
/// mode determines how the colors of an object you draw are
/// mixed with the colors that are already in the buffer.
///
/// The class is composed of 6 components, each of which has its
/// own public member variable:
/// \li %Color Source Factor (@ref colorSrcFactor)
/// \li %Color Destination Factor (@ref colorDstFactor)
/// \li %Color Blend Equation (@ref colorEquation)
/// \li Alpha Source Factor (@ref alphaSrcFactor)
/// \li Alpha Destination Factor (@ref alphaDstFactor)
/// \li Alpha Blend Equation (@ref alphaEquation)
///
/// The source factor specifies how the pixel you are drawing contributes
/// to the final color. The destination factor specifies how the pixel
/// already drawn in the buffer contributes to the final color.
///
/// The color channels RGB (red, green, blue; simply referred to as
/// color) and A (alpha; the transparency) can be treated separately. This
/// separation can be useful for specific blend modes, but most often you
/// won't need it and will simply treat the color as a single unit.
///
/// The blend factors and equations correspond to their OpenGL equivalents.
/// In general, the color of the resulting pixel is calculated according
/// to the following formula (\a src is the color of the source pixel, \a dst
/// the color of the destination pixel, the other variables correspond to the
/// public members, with the equations being + or - operators):
/// \code
/// dst.rgb = colorSrcFactor * src.rgb (colorEquation) colorDstFactor * dst.rgb
/// dst.a = alphaSrcFactor * src.a (alphaEquation) alphaDstFactor * dst.a
/// \endcode
/// All factors and colors are represented as floating point numbers between
/// 0 and 1. Where necessary, the result is clamped to fit in that range.
///
/// The most common blending modes are defined as constants
/// in the sf namespace:
///
/// \code
/// sf::BlendMode alphaBlending = sf::BlendAlpha;
/// sf::BlendMode additiveBlending = sf::BlendAdd;
/// sf::BlendMode multiplicativeBlending = sf::BlendMultipy;
/// sf::BlendMode noBlending = sf::BlendNone;
/// \endcode
///
/// In SFML, a blend mode can be specified every time you draw a sf::Drawable
/// object to a render target. It is part of the sf::RenderStates compound
/// that is passed to the member function sf::RenderTarget::draw().
///
/// \see sf::RenderStates, sf::RenderTarget
///
////////////////////////////////////////////////////////////

4
include/SFML/Graphics/RenderStates.hpp
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@ -66,7 +66,7 @@ public :
/// \param theBlendMode Blend mode to use
///
////////////////////////////////////////////////////////////
RenderStates(BlendMode theBlendMode);
RenderStates(const BlendMode& theBlendMode);
////////////////////////////////////////////////////////////
/// \brief Construct a default set of render states with a custom transform
@ -101,7 +101,7 @@ public :
/// \param theShader Shader to use
///
////////////////////////////////////////////////////////////
RenderStates(BlendMode theBlendMode, const Transform& theTransform,
RenderStates(const BlendMode& theBlendMode, const Transform& theTransform,
const Texture* theTexture, const Shader* theShader);
////////////////////////////////////////////////////////////

2
include/SFML/Graphics/RenderTarget.hpp
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@ -354,7 +354,7 @@ private:
/// \param mode Blending mode to apply
///
////////////////////////////////////////////////////////////
void applyBlendMode(BlendMode mode);
void applyBlendMode(const BlendMode& mode);
////////////////////////////////////////////////////////////
/// \brief Apply a new transform

103
src/SFML/Graphics/BlendMode.cpp Normal file
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@ -0,0 +1,103 @@
////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2014 Laurent Gomila (laurent.gom@gmail.com)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Graphics/BlendMode.hpp>
namespace sf
{
////////////////////////////////////////////////////////////
// Commonly used blending modes
////////////////////////////////////////////////////////////
const BlendMode BlendAlpha(BlendMode::SrcAlpha, BlendMode::OneMinusSrcAlpha, BlendMode::Add,
BlendMode::One, BlendMode::OneMinusSrcAlpha, BlendMode::Add);
const BlendMode BlendAdd(BlendMode::SrcAlpha, BlendMode::One, BlendMode::Add,
BlendMode::One, BlendMode::One, BlendMode::Add);
const BlendMode BlendMultiply(BlendMode::DstColor, BlendMode::Zero);
const BlendMode BlendNone(BlendMode::One, BlendMode::Zero);
////////////////////////////////////////////////////////////
BlendMode::BlendMode() :
colorSrcFactor(BlendMode::SrcAlpha),
colorDstFactor(BlendMode::OneMinusSrcAlpha),
colorEquation (BlendMode::Add),
alphaSrcFactor(BlendMode::One),
alphaDstFactor(BlendMode::OneMinusSrcAlpha),
alphaEquation (BlendMode::Add)
{
}
////////////////////////////////////////////////////////////
BlendMode::BlendMode(Factor sourceFactor, Factor destinationFactor, Equation blendEquation) :
colorSrcFactor(sourceFactor),
colorDstFactor(destinationFactor),
colorEquation (blendEquation),
alphaSrcFactor(sourceFactor),
alphaDstFactor(destinationFactor),
alphaEquation (blendEquation)
{
}
////////////////////////////////////////////////////////////
BlendMode::BlendMode(Factor colorSourceFactor, Factor colorDestinationFactor,
Equation colorBlendEquation, Factor alphaSourceFactor,
Factor alphaDestinationFactor, Equation alphaBlendEquation) :
colorSrcFactor(colorSourceFactor),
colorDstFactor(colorDestinationFactor),
colorEquation (colorBlendEquation),
alphaSrcFactor(alphaSourceFactor),
alphaDstFactor(alphaDestinationFactor),
alphaEquation (alphaBlendEquation)
{
}
////////////////////////////////////////////////////////////
bool operator ==(const BlendMode& left, const BlendMode& right)
{
return (left.colorSrcFactor == right.colorSrcFactor) &&
(left.colorDstFactor == right.colorDstFactor) &&
(left.colorEquation == right.colorEquation) &&
(left.alphaSrcFactor == right.alphaSrcFactor) &&
(left.alphaDstFactor == right.alphaDstFactor) &&
(left.alphaEquation == right.alphaEquation);
}
////////////////////////////////////////////////////////////
bool operator !=(const BlendMode& left, const BlendMode& right)
{
return !(left == right);
}
} // namespace sf

1
src/SFML/Graphics/CMakeLists.txt
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@ -4,6 +4,7 @@ set(SRCROOT ${PROJECT_SOURCE_DIR}/src/SFML/Graphics)
# all source files
set(SRC
${SRCROOT}/BlendMode.cpp
${INCROOT}/BlendMode.hpp
${SRCROOT}/Color.cpp
${INCROOT}/Color.hpp

4
src/SFML/Graphics/GLExtensions.hpp
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@ -35,7 +35,9 @@
#include <SFML/OpenGL.hpp>
#define GLEXT_blend_func_separate GL_OES_blend_func_separate
#define GLEXT_blend_equation_separate GL_OES_blend_equation_separate
#define GLEXT_glBlendFuncSeparate glBlendFuncSeparateOES
#define GLEXT_glBlendEquationSeparate glBlendEquationSeparateOES
#define GLEXT_framebuffer_object GL_OES_framebuffer_object
#define GLEXT_glGenFramebuffers glGenFramebuffersOES
#define GLEXT_glGenRenderbuffers glGenRenderbuffersOES
@ -63,7 +65,9 @@
#include <SFML/OpenGL.hpp>
#define GLEXT_blend_func_separate GLEW_EXT_blend_func_separate
#define GLEXT_blend_equation_separate GLEW_EXT_blend_equation_separate
#define GLEXT_glBlendFuncSeparate glBlendFuncSeparateEXT
#define GLEXT_glBlendEquationSeparate glBlendEquationSeparateEXT
#define GLEXT_framebuffer_object GLEW_EXT_framebuffer_object
#define GLEXT_glGenFramebuffers glGenFramebuffersEXT
#define GLEXT_glGenRenderbuffers glGenRenderbuffersEXT

4
src/SFML/Graphics/RenderStates.cpp
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@ -56,7 +56,7 @@ shader (NULL)
////////////////////////////////////////////////////////////
RenderStates::RenderStates(BlendMode theBlendMode) :
RenderStates::RenderStates(const BlendMode& theBlendMode) :
blendMode(theBlendMode),
transform(),
texture (NULL),
@ -86,7 +86,7 @@ shader (theShader)
////////////////////////////////////////////////////////////
RenderStates::RenderStates(BlendMode theBlendMode, const Transform& theTransform,
RenderStates::RenderStates(const BlendMode& theBlendMode, const Transform& theTransform,
const Texture* theTexture, const Shader* theShader) :
blendMode(theBlendMode),
transform(theTransform),

84
src/SFML/Graphics/RenderTarget.cpp
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@ -35,6 +35,41 @@
#include <iostream>
namespace
{
// Convert an sf::BlendMode::Factor constant to the corresponding OpenGL constant.
sf::Uint32 factorToGlConstant(sf::BlendMode::Factor blendFactor)
{
switch (blendFactor)
{
default:
case sf::BlendMode::Zero: return GL_ZERO;
case sf::BlendMode::One: return GL_ONE;
case sf::BlendMode::SrcColor: return GL_SRC_COLOR;
case sf::BlendMode::OneMinusSrcColor: return GL_ONE_MINUS_SRC_COLOR;
case sf::BlendMode::DstColor: return GL_DST_COLOR;
case sf::BlendMode::OneMinusDstColor: return GL_ONE_MINUS_DST_COLOR;
case sf::BlendMode::SrcAlpha: return GL_SRC_ALPHA;
case sf::BlendMode::OneMinusSrcAlpha: return GL_ONE_MINUS_SRC_ALPHA;
case sf::BlendMode::DstAlpha: return GL_DST_ALPHA;
case sf::BlendMode::OneMinusDstAlpha: return GL_ONE_MINUS_DST_ALPHA;
}
}
// Convert an sf::BlendMode::BlendEquation constant to the corresponding OpenGL constant.
sf::Uint32 equationToGlConstant(sf::BlendMode::Equation blendEquation)
{
switch (blendEquation)
{
default:
case sf::BlendMode::Add: return GL_FUNC_ADD;
case sf::BlendMode::Subtract: return GL_FUNC_SUBTRACT;
}
}
}
namespace sf
{
////////////////////////////////////////////////////////////
@ -369,49 +404,31 @@ void RenderTarget::applyCurrentView()
////////////////////////////////////////////////////////////
void RenderTarget::applyBlendMode(BlendMode mode)
void RenderTarget::applyBlendMode(const BlendMode& mode)
{
switch (mode)
{
// glBlendFuncSeparate is used when available to avoid an incorrect alpha value when the target
// is a RenderTexture -- in this case the alpha value must be written directly to the target buffer
// Alpha blending
default :
case BlendAlpha :
// Apply the blend mode, falling back to the non-separate versions if necessary
if (GLEXT_blend_func_separate)
{
glCheck(GLEXT_glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
glCheck(GLEXT_glBlendFuncSeparate(
factorToGlConstant(mode.colorSrcFactor), factorToGlConstant(mode.colorDstFactor),
factorToGlConstant(mode.alphaSrcFactor), factorToGlConstant(mode.alphaDstFactor)));
}
else
{
glCheck(glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA));
glCheck(glBlendFunc(
factorToGlConstant(mode.colorSrcFactor),
factorToGlConstant(mode.colorDstFactor)));
}
break;
// Additive blending
case BlendAdd :
if (GLEXT_blend_func_separate)
if (GLEXT_blend_equation_separate)
{
glCheck(GLEXT_glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE, GL_ONE, GL_ONE));
glCheck(GLEXT_glBlendEquationSeparate(
equationToGlConstant(mode.colorEquation),
equationToGlConstant(mode.alphaEquation)));
}
else
{
glCheck(glBlendFunc(GL_SRC_ALPHA, GL_ONE));
}
break;
// Multiplicative blending
case BlendMultiply :
glCheck(glBlendFunc(GL_DST_COLOR, GL_ZERO));
break;
// No blending
case BlendNone :
glCheck(glBlendFunc(GL_ONE, GL_ZERO));
break;
glCheck(glBlendEquation(equationToGlConstant(mode.colorEquation)));
}
m_cache.lastBlendMode = mode;
@ -462,8 +479,9 @@ void RenderTarget::applyShader(const Shader* shader)
// to render them.
//
// * Blending mode
// It's a simple integral value, so we can easily check
// whether the value to apply is the same as before or not.
// Since it overloads the == operator, we can easily check
// whether any of the 6 blending components changed and,
// thus, whether we need to update the blend mode.
//
// * Texture
// Storing the pointer or OpenGL ID of the last used texture