imgui-sfml-premake/sfml/src/SFML/Graphics/RenderTarget.cpp

961 lines
32 KiB
C++

////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2025 Laurent Gomila (laurent@sfml-dev.org)
//
// 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/Drawable.hpp>
#include <SFML/Graphics/GLCheck.hpp>
#include <SFML/Graphics/GLExtensions.hpp>
#include <SFML/Graphics/RenderTarget.hpp>
#include <SFML/Graphics/Shader.hpp>
#include <SFML/Graphics/Texture.hpp>
#include <SFML/Graphics/VertexBuffer.hpp>
#include <SFML/Window/Context.hpp>
#include <SFML/System/EnumArray.hpp>
#include <SFML/System/Err.hpp>
#include <algorithm>
#include <mutex>
#include <ostream>
#include <unordered_map>
#include <cassert>
#include <cmath>
#include <cstddef>
namespace
{
// A nested named namespace is used here to allow unity builds of SFML.
namespace RenderTargetImpl
{
// Mutex to protect ID generation and our context-RenderTarget-map
std::recursive_mutex& getMutex()
{
static std::recursive_mutex mutex;
return mutex;
}
// Unique identifier, used for identifying RenderTargets when
// tracking the currently active RenderTarget within a given context
std::uint64_t getUniqueId()
{
const std::lock_guard lock(getMutex());
static std::uint64_t id = 1; // start at 1, zero is "no RenderTarget"
return id++;
}
// Map to help us detect whether a different RenderTarget
// has been activated within a single context
using ContextRenderTargetMap = std::unordered_map<std::uint64_t, std::uint64_t>;
ContextRenderTargetMap& getContextRenderTargetMap()
{
static ContextRenderTargetMap contextRenderTargetMap;
return contextRenderTargetMap;
}
// Check if a RenderTarget with the given ID is active in the current context
bool isActive(std::uint64_t id)
{
const auto it = getContextRenderTargetMap().find(sf::Context::getActiveContextId());
return (it != getContextRenderTargetMap().end()) && (it->second == id);
}
// Convert an sf::BlendMode::Factor constant to the corresponding OpenGL constant.
std::uint32_t factorToGlConstant(sf::BlendMode::Factor blendFactor)
{
// clang-format off
switch (blendFactor)
{
case sf::BlendMode::Factor::Zero: return GL_ZERO;
case sf::BlendMode::Factor::One: return GL_ONE;
case sf::BlendMode::Factor::SrcColor: return GL_SRC_COLOR;
case sf::BlendMode::Factor::OneMinusSrcColor: return GL_ONE_MINUS_SRC_COLOR;
case sf::BlendMode::Factor::DstColor: return GL_DST_COLOR;
case sf::BlendMode::Factor::OneMinusDstColor: return GL_ONE_MINUS_DST_COLOR;
case sf::BlendMode::Factor::SrcAlpha: return GL_SRC_ALPHA;
case sf::BlendMode::Factor::OneMinusSrcAlpha: return GL_ONE_MINUS_SRC_ALPHA;
case sf::BlendMode::Factor::DstAlpha: return GL_DST_ALPHA;
case sf::BlendMode::Factor::OneMinusDstAlpha: return GL_ONE_MINUS_DST_ALPHA;
}
// clang-format on
sf::err() << "Invalid value for sf::BlendMode::Factor! Fallback to sf::BlendMode::Factor::Zero." << std::endl;
assert(false);
return GL_ZERO;
}
// Convert an sf::BlendMode::Equation constant to the corresponding OpenGL constant.
std::uint32_t equationToGlConstant(sf::BlendMode::Equation blendEquation)
{
switch (blendEquation)
{
case sf::BlendMode::Equation::Add:
return GLEXT_GL_FUNC_ADD;
case sf::BlendMode::Equation::Subtract:
if (GLEXT_blend_subtract)
return GLEXT_GL_FUNC_SUBTRACT;
break;
case sf::BlendMode::Equation::ReverseSubtract:
if (GLEXT_blend_subtract)
return GLEXT_GL_FUNC_REVERSE_SUBTRACT;
break;
case sf::BlendMode::Equation::Min:
if (GLEXT_blend_minmax)
return GLEXT_GL_MIN;
break;
case sf::BlendMode::Equation::Max:
if (GLEXT_blend_minmax)
return GLEXT_GL_MAX;
break;
}
static bool warned = false;
if (!warned)
{
sf::err() << "OpenGL extension EXT_blend_minmax or EXT_blend_subtract unavailable" << '\n'
<< "Some blending equations will fallback to sf::BlendMode::Equation::Add" << '\n'
<< "Ensure that hardware acceleration is enabled if available" << std::endl;
warned = true;
}
return GLEXT_GL_FUNC_ADD;
}
// Convert an UpdateOperation constant to the corresponding OpenGL constant.
std::uint32_t stencilOperationToGlConstant(sf::StencilUpdateOperation operation)
{
// clang-format off
switch (operation)
{
case sf::StencilUpdateOperation::Keep: return GL_KEEP;
case sf::StencilUpdateOperation::Zero: return GL_ZERO;
case sf::StencilUpdateOperation::Replace: return GL_REPLACE;
case sf::StencilUpdateOperation::Increment: return GL_INCR;
case sf::StencilUpdateOperation::Decrement: return GL_DECR;
case sf::StencilUpdateOperation::Invert: return GL_INVERT;
}
// clang-format on
sf::err() << "Invalid value for sf::StencilUpdateOperation! Fallback to sf::StencilMode::Keep." << std::endl;
assert(false);
return GL_KEEP;
}
// Convert a Comparison constant to the corresponding OpenGL constant.
std::uint32_t stencilFunctionToGlConstant(sf::StencilComparison comparison)
{
// clang-format off
switch (comparison)
{
case sf::StencilComparison::Never: return GL_NEVER;
case sf::StencilComparison::Less: return GL_LESS;
case sf::StencilComparison::LessEqual: return GL_LEQUAL;
case sf::StencilComparison::Greater: return GL_GREATER;
case sf::StencilComparison::GreaterEqual: return GL_GEQUAL;
case sf::StencilComparison::Equal: return GL_EQUAL;
case sf::StencilComparison::NotEqual: return GL_NOTEQUAL;
case sf::StencilComparison::Always: return GL_ALWAYS;
}
// clang-format on
sf::err() << "Invalid value for sf::StencilComparison! Fallback to sf::StencilMode::Always." << std::endl;
assert(false);
return GL_ALWAYS;
}
} // namespace RenderTargetImpl
} // namespace
namespace sf
{
////////////////////////////////////////////////////////////
void RenderTarget::clear(Color color)
{
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
// Unbind texture to fix RenderTexture preventing clear
applyTexture(nullptr);
// Apply the view (scissor testing can affect clearing)
if (!m_cache.enable || m_cache.viewChanged)
applyCurrentView();
glCheck(glClearColor(color.r / 255.f, color.g / 255.f, color.b / 255.f, color.a / 255.f));
glCheck(glClear(GL_COLOR_BUFFER_BIT));
}
}
////////////////////////////////////////////////////////////
void RenderTarget::clearStencil(StencilValue stencilValue)
{
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
// Unbind texture to fix RenderTexture preventing clear
applyTexture(nullptr);
// Apply the view (scissor testing can affect clearing)
if (!m_cache.enable || m_cache.viewChanged)
applyCurrentView();
glCheck(glClearStencil(static_cast<int>(stencilValue.value)));
glCheck(glClear(GL_STENCIL_BUFFER_BIT));
}
}
////////////////////////////////////////////////////////////
void RenderTarget::clear(Color color, StencilValue stencilValue)
{
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
// Unbind texture to fix RenderTexture preventing clear
applyTexture(nullptr);
// Apply the view (scissor testing can affect clearing)
if (!m_cache.enable || m_cache.viewChanged)
applyCurrentView();
glCheck(glClearColor(color.r / 255.f, color.g / 255.f, color.b / 255.f, color.a / 255.f));
glCheck(glClearStencil(static_cast<int>(stencilValue.value)));
glCheck(glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT));
}
}
////////////////////////////////////////////////////////////
void RenderTarget::setView(const View& view)
{
m_view = view;
m_cache.viewChanged = true;
}
////////////////////////////////////////////////////////////
const View& RenderTarget::getView() const
{
return m_view;
}
////////////////////////////////////////////////////////////
const View& RenderTarget::getDefaultView() const
{
return m_defaultView;
}
////////////////////////////////////////////////////////////
IntRect RenderTarget::getViewport(const View& view) const
{
const auto [width, height] = Vector2f(getSize());
const FloatRect& viewport = view.getViewport();
return IntRect(Rect<long>({std::lround(width * viewport.position.x), std::lround(height * viewport.position.y)},
{std::lround(width * viewport.size.x), std::lround(height * viewport.size.y)}));
}
////////////////////////////////////////////////////////////
IntRect RenderTarget::getScissor(const View& view) const
{
const auto [width, height] = Vector2f(getSize());
const FloatRect& scissor = view.getScissor();
return IntRect(Rect<long>({std::lround(width * scissor.position.x), std::lround(height * scissor.position.y)},
{std::lround(width * scissor.size.x), std::lround(height * scissor.size.y)}));
}
////////////////////////////////////////////////////////////
Vector2f RenderTarget::mapPixelToCoords(Vector2i point) const
{
return mapPixelToCoords(point, getView());
}
////////////////////////////////////////////////////////////
Vector2f RenderTarget::mapPixelToCoords(Vector2i point, const View& view) const
{
// First, convert from viewport coordinates to homogeneous coordinates
const FloatRect viewport = FloatRect(getViewport(view));
const Vector2f
normalized = Vector2f(-1, 1) +
Vector2f(2, -2).componentWiseMul(Vector2f(point) - viewport.position).componentWiseDiv(viewport.size);
// Then transform by the inverse of the view matrix
return view.getInverseTransform().transformPoint(normalized);
}
////////////////////////////////////////////////////////////
Vector2i RenderTarget::mapCoordsToPixel(Vector2f point) const
{
return mapCoordsToPixel(point, getView());
}
////////////////////////////////////////////////////////////
Vector2i RenderTarget::mapCoordsToPixel(Vector2f point, const View& view) const
{
// First, transform the point by the view matrix
const Vector2f normalized = view.getTransform().transformPoint(point);
// Then convert to viewport coordinates
const FloatRect viewport = FloatRect(getViewport(view));
return Vector2i(
(normalized.componentWiseMul({1, -1}) + sf::Vector2f(1, 1)).componentWiseDiv({2, 2}).componentWiseMul(viewport.size) +
viewport.position);
}
////////////////////////////////////////////////////////////
void RenderTarget::draw(const Drawable& drawable, const RenderStates& states)
{
drawable.draw(*this, states);
}
////////////////////////////////////////////////////////////
void RenderTarget::draw(const Vertex* vertices, std::size_t vertexCount, PrimitiveType type, const RenderStates& states)
{
// Nothing to draw?
if (!vertices || (vertexCount == 0))
return;
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
// Check if the vertex count is low enough so that we can pre-transform them
const bool useVertexCache = (vertexCount <= m_cache.vertexCache.size());
if (useVertexCache)
{
// Pre-transform the vertices and store them into the vertex cache
for (std::size_t i = 0; i < vertexCount; ++i)
{
Vertex& vertex = m_cache.vertexCache[i];
vertex.position = states.transform * vertices[i].position;
vertex.color = vertices[i].color;
vertex.texCoords = vertices[i].texCoords;
}
}
setupDraw(useVertexCache, states);
// Check if texture coordinates array is needed, and update client state accordingly
const bool enableTexCoordsArray = (states.texture || states.shader);
if (!m_cache.enable || (enableTexCoordsArray != m_cache.texCoordsArrayEnabled))
{
if (enableTexCoordsArray)
glCheck(glEnableClientState(GL_TEXTURE_COORD_ARRAY));
else
glCheck(glDisableClientState(GL_TEXTURE_COORD_ARRAY));
}
// If we switch between non-cache and cache mode or enable texture
// coordinates we need to set up the pointers to the vertices' components
if (!m_cache.enable || !useVertexCache || !m_cache.useVertexCache)
{
const auto* data = reinterpret_cast<const std::byte*>(vertices);
// If we pre-transform the vertices, we must use our internal vertex cache
if (useVertexCache)
data = reinterpret_cast<const std::byte*>(m_cache.vertexCache.data());
glCheck(glVertexPointer(2, GL_FLOAT, sizeof(Vertex), data + 0));
glCheck(glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(Vertex), data + 8));
if (enableTexCoordsArray)
glCheck(glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), data + 12));
}
else if (enableTexCoordsArray && !m_cache.texCoordsArrayEnabled)
{
// If we enter this block, we are already using our internal vertex cache
const auto* data = reinterpret_cast<const std::byte*>(m_cache.vertexCache.data());
glCheck(glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), data + 12));
}
drawPrimitives(type, 0, vertexCount);
cleanupDraw(states);
// Update the cache
m_cache.useVertexCache = useVertexCache;
m_cache.texCoordsArrayEnabled = enableTexCoordsArray;
}
}
////////////////////////////////////////////////////////////
void RenderTarget::draw(const VertexBuffer& vertexBuffer, const RenderStates& states)
{
draw(vertexBuffer, 0, vertexBuffer.getVertexCount(), states);
}
////////////////////////////////////////////////////////////
void RenderTarget::draw(const VertexBuffer& vertexBuffer, std::size_t firstVertex, std::size_t vertexCount, const RenderStates& states)
{
// VertexBuffer not supported?
if (!VertexBuffer::isAvailable())
{
err() << "sf::VertexBuffer is not available, drawing skipped" << std::endl;
return;
}
// Sanity check
if (firstVertex > vertexBuffer.getVertexCount())
return;
// Clamp vertexCount to something that makes sense
vertexCount = std::min(vertexCount, vertexBuffer.getVertexCount() - firstVertex);
// Nothing to draw?
if (!vertexCount || !vertexBuffer.getNativeHandle())
return;
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
setupDraw(false, states);
// Bind vertex buffer
VertexBuffer::bind(&vertexBuffer);
// Always enable texture coordinates
if (!m_cache.enable || !m_cache.texCoordsArrayEnabled)
glCheck(glEnableClientState(GL_TEXTURE_COORD_ARRAY));
glCheck(glVertexPointer(2, GL_FLOAT, sizeof(Vertex), reinterpret_cast<const void*>(0)));
glCheck(glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(Vertex), reinterpret_cast<const void*>(8)));
glCheck(glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), reinterpret_cast<const void*>(12)));
drawPrimitives(vertexBuffer.getPrimitiveType(), firstVertex, vertexCount);
// Unbind vertex buffer
VertexBuffer::bind(nullptr);
cleanupDraw(states);
// Update the cache
m_cache.useVertexCache = false;
m_cache.texCoordsArrayEnabled = true;
}
}
////////////////////////////////////////////////////////////
bool RenderTarget::isSrgb() const
{
// By default sRGB encoding is not enabled for an arbitrary RenderTarget
return false;
}
////////////////////////////////////////////////////////////
bool RenderTarget::setActive(bool active)
{
// Mark this RenderTarget as active or no longer active in the tracking map
const std::lock_guard lock(RenderTargetImpl::getMutex());
const std::uint64_t contextId = Context::getActiveContextId();
using RenderTargetImpl::getContextRenderTargetMap;
auto& contextRenderTargetMap = getContextRenderTargetMap();
const auto it = contextRenderTargetMap.find(contextId);
if (active)
{
if (it == contextRenderTargetMap.end())
{
contextRenderTargetMap[contextId] = m_id;
m_cache.glStatesSet = false;
m_cache.enable = false;
}
else if (it->second != m_id)
{
it->second = m_id;
m_cache.enable = false;
}
}
else
{
if (it != contextRenderTargetMap.end())
contextRenderTargetMap.erase(it);
m_cache.enable = false;
}
return true;
}
////////////////////////////////////////////////////////////
void RenderTarget::pushGLStates()
{
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
#ifdef SFML_DEBUG
// make sure that the user didn't leave an unchecked OpenGL error
const GLenum error = glGetError();
if (error != GL_NO_ERROR)
{
err() << "OpenGL error (" << error << ") detected in user code, "
<< "you should check for errors with glGetError()" << std::endl;
}
#endif
#ifndef SFML_OPENGL_ES
glCheck(glPushClientAttrib(GL_CLIENT_ALL_ATTRIB_BITS));
glCheck(glPushAttrib(GL_ALL_ATTRIB_BITS));
#endif
glCheck(glMatrixMode(GL_MODELVIEW));
glCheck(glPushMatrix());
glCheck(glMatrixMode(GL_PROJECTION));
glCheck(glPushMatrix());
glCheck(glMatrixMode(GL_TEXTURE));
glCheck(glPushMatrix());
}
resetGLStates();
}
////////////////////////////////////////////////////////////
void RenderTarget::popGLStates()
{
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
glCheck(glMatrixMode(GL_PROJECTION));
glCheck(glPopMatrix());
glCheck(glMatrixMode(GL_MODELVIEW));
glCheck(glPopMatrix());
glCheck(glMatrixMode(GL_TEXTURE));
glCheck(glPopMatrix());
#ifndef SFML_OPENGL_ES
glCheck(glPopClientAttrib());
glCheck(glPopAttrib());
#endif
}
}
////////////////////////////////////////////////////////////
void RenderTarget::resetGLStates()
{
// Check here to make sure a context change does not happen after activate(true)
const bool shaderAvailable = Shader::isAvailable();
const bool vertexBufferAvailable = VertexBuffer::isAvailable();
// Workaround for states not being properly reset on
// macOS unless a context switch really takes place
#if defined(SFML_SYSTEM_MACOS)
if (!setActive(false))
{
err() << "Failed to set render target inactive" << std::endl;
}
#endif
if (RenderTargetImpl::isActive(m_id) || setActive(true))
{
// Make sure that extensions are initialized
priv::ensureExtensionsInit();
// Make sure that the texture unit which is active is the number 0
if (GLEXT_multitexture)
{
glCheck(GLEXT_glClientActiveTexture(GLEXT_GL_TEXTURE0));
glCheck(GLEXT_glActiveTexture(GLEXT_GL_TEXTURE0));
}
// Define the default OpenGL states
glCheck(glDisable(GL_CULL_FACE));
glCheck(glDisable(GL_LIGHTING));
glCheck(glDisable(GL_STENCIL_TEST));
glCheck(glDisable(GL_DEPTH_TEST));
glCheck(glDisable(GL_ALPHA_TEST));
glCheck(glDisable(GL_SCISSOR_TEST));
glCheck(glEnable(GL_TEXTURE_2D));
glCheck(glEnable(GL_BLEND));
glCheck(glMatrixMode(GL_MODELVIEW));
glCheck(glLoadIdentity());
glCheck(glEnableClientState(GL_VERTEX_ARRAY));
glCheck(glEnableClientState(GL_COLOR_ARRAY));
glCheck(glEnableClientState(GL_TEXTURE_COORD_ARRAY));
glCheck(glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE));
m_cache.scissorEnabled = false;
m_cache.stencilEnabled = false;
m_cache.glStatesSet = true;
// Apply the default SFML states
applyBlendMode(BlendAlpha);
applyStencilMode(StencilMode());
applyTexture(nullptr);
if (shaderAvailable)
applyShader(nullptr);
if (vertexBufferAvailable)
glCheck(VertexBuffer::bind(nullptr));
m_cache.texCoordsArrayEnabled = true;
m_cache.useVertexCache = false;
// Set the default view
setView(getView());
m_cache.enable = true;
}
}
////////////////////////////////////////////////////////////
void RenderTarget::initialize()
{
// Setup the default and current views
m_defaultView = View(FloatRect({0, 0}, Vector2f(getSize())));
m_view = m_defaultView;
// Set GL states only on first draw, so that we don't pollute user's states
m_cache.glStatesSet = false;
// Generate a unique ID for this RenderTarget to track
// whether it is active within a specific context
m_id = RenderTargetImpl::getUniqueId();
}
////////////////////////////////////////////////////////////
void RenderTarget::applyCurrentView()
{
// Set the viewport
const IntRect viewport = getViewport(m_view);
const int viewportTop = static_cast<int>(getSize().y) - (viewport.position.y + viewport.size.y);
glCheck(glViewport(viewport.position.x, viewportTop, viewport.size.x, viewport.size.y));
// Set the scissor rectangle and enable/disable scissor testing
if (m_view.getScissor() == FloatRect({0, 0}, {1, 1}))
{
if (!m_cache.enable || m_cache.scissorEnabled)
{
glCheck(glDisable(GL_SCISSOR_TEST));
m_cache.scissorEnabled = false;
}
}
else
{
const IntRect pixelScissor = getScissor(m_view);
const int scissorTop = static_cast<int>(getSize().y) - (pixelScissor.position.y + pixelScissor.size.y);
glCheck(glScissor(pixelScissor.position.x, scissorTop, pixelScissor.size.x, pixelScissor.size.y));
if (!m_cache.enable || !m_cache.scissorEnabled)
{
glCheck(glEnable(GL_SCISSOR_TEST));
m_cache.scissorEnabled = true;
}
}
// Set the projection matrix
glCheck(glMatrixMode(GL_PROJECTION));
glCheck(glLoadMatrixf(m_view.getTransform().getMatrix()));
// Go back to model-view mode
glCheck(glMatrixMode(GL_MODELVIEW));
m_cache.viewChanged = false;
}
////////////////////////////////////////////////////////////
void RenderTarget::applyBlendMode(const BlendMode& mode)
{
using RenderTargetImpl::equationToGlConstant;
using RenderTargetImpl::factorToGlConstant;
// Apply the blend mode, falling back to the non-separate versions if necessary
if (GLEXT_blend_func_separate)
{
glCheck(GLEXT_glBlendFuncSeparate(factorToGlConstant(mode.colorSrcFactor),
factorToGlConstant(mode.colorDstFactor),
factorToGlConstant(mode.alphaSrcFactor),
factorToGlConstant(mode.alphaDstFactor)));
}
else
{
glCheck(glBlendFunc(factorToGlConstant(mode.colorSrcFactor), factorToGlConstant(mode.colorDstFactor)));
}
if (GLEXT_blend_minmax || GLEXT_blend_subtract)
{
if (GLEXT_blend_equation_separate)
{
glCheck(GLEXT_glBlendEquationSeparate(equationToGlConstant(mode.colorEquation),
equationToGlConstant(mode.alphaEquation)));
}
else
{
glCheck(GLEXT_glBlendEquation(equationToGlConstant(mode.colorEquation)));
}
}
else if ((mode.colorEquation != BlendMode::Equation::Add) || (mode.alphaEquation != BlendMode::Equation::Add))
{
static bool warned = false;
if (!warned)
{
#ifdef SFML_OPENGL_ES
err() << "OpenGL ES extension OES_blend_subtract unavailable" << std::endl;
#else
err() << "OpenGL extension EXT_blend_minmax and EXT_blend_subtract unavailable" << std::endl;
#endif
err() << "Selecting a blend equation not possible" << '\n'
<< "Ensure that hardware acceleration is enabled if available" << std::endl;
warned = true;
}
}
m_cache.lastBlendMode = mode;
}
////////////////////////////////////////////////////////////
void RenderTarget::applyStencilMode(const StencilMode& mode)
{
using RenderTargetImpl::stencilFunctionToGlConstant;
using RenderTargetImpl::stencilOperationToGlConstant;
// Fast path if we have a default (disabled) stencil mode
if (mode == StencilMode())
{
if (!m_cache.enable || m_cache.stencilEnabled)
{
glCheck(glDisable(GL_STENCIL_TEST));
glCheck(glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE));
m_cache.stencilEnabled = false;
}
}
else
{
// Apply the stencil mode
if (!m_cache.enable || !m_cache.stencilEnabled)
glCheck(glEnable(GL_STENCIL_TEST));
glCheck(glStencilOp(GL_KEEP,
stencilOperationToGlConstant(mode.stencilUpdateOperation),
stencilOperationToGlConstant(mode.stencilUpdateOperation)));
glCheck(glStencilFunc(stencilFunctionToGlConstant(mode.stencilComparison),
static_cast<int>(mode.stencilReference.value),
mode.stencilMask.value));
m_cache.stencilEnabled = true;
}
m_cache.lastStencilMode = mode;
}
////////////////////////////////////////////////////////////
void RenderTarget::applyTransform(const Transform& transform)
{
// No need to call glMatrixMode(GL_MODELVIEW), it is always the
// current mode (for optimization purpose, since it's the most used)
if (transform == Transform::Identity)
glCheck(glLoadIdentity());
else
glCheck(glLoadMatrixf(transform.getMatrix()));
}
////////////////////////////////////////////////////////////
void RenderTarget::applyTexture(const Texture* texture, CoordinateType coordinateType)
{
Texture::bind(texture, coordinateType);
m_cache.lastTextureId = texture ? texture->m_cacheId : 0;
m_cache.lastCoordinateType = coordinateType;
}
////////////////////////////////////////////////////////////
void RenderTarget::applyShader(const Shader* shader)
{
Shader::bind(shader);
}
////////////////////////////////////////////////////////////
void RenderTarget::setupDraw(bool useVertexCache, const RenderStates& states)
{
// GL_FRAMEBUFFER_SRGB is not available on OpenGL ES
// If a framebuffer supports sRGB, it will always be enabled on OpenGL ES
#ifndef SFML_OPENGL_ES
// Enable or disable sRGB encoding
// This is needed for drivers that do not check the format of the surface drawn to before applying sRGB conversion
if (!m_cache.enable)
{
if (isSrgb())
glCheck(glEnable(GL_FRAMEBUFFER_SRGB));
else
glCheck(glDisable(GL_FRAMEBUFFER_SRGB));
}
#endif
// First set the persistent OpenGL states if it's the very first call
if (!m_cache.glStatesSet)
resetGLStates();
if (useVertexCache)
{
// Since vertices are transformed, we must use an identity transform to render them
if (!m_cache.enable || !m_cache.useVertexCache)
glCheck(glLoadIdentity());
}
else
{
applyTransform(states.transform);
}
// Apply the view
if (!m_cache.enable || m_cache.viewChanged)
applyCurrentView();
// Apply the blend mode
if (!m_cache.enable || (states.blendMode != m_cache.lastBlendMode))
applyBlendMode(states.blendMode);
// Apply the stencil mode
if (!m_cache.enable || (states.stencilMode != m_cache.lastStencilMode))
applyStencilMode(states.stencilMode);
// Mask the color buffer off if necessary
if (states.stencilMode.stencilOnly)
glCheck(glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE));
// Apply the texture
if (!m_cache.enable || (states.texture && states.texture->m_fboAttachment))
{
// If the texture is an FBO attachment, always rebind it
// in order to inform the OpenGL driver that we want changes
// made to it in other contexts to be visible here as well
// This saves us from having to call glFlush() in
// RenderTextureImplFBO which can be quite costly
// See: https://www.khronos.org/opengl/wiki/Memory_Model
applyTexture(states.texture, states.coordinateType);
}
else
{
const std::uint64_t textureId = states.texture ? states.texture->m_cacheId : 0;
if (textureId != m_cache.lastTextureId || states.coordinateType != m_cache.lastCoordinateType)
applyTexture(states.texture, states.coordinateType);
}
// Apply the shader
if (states.shader)
applyShader(states.shader);
}
////////////////////////////////////////////////////////////
void RenderTarget::drawPrimitives(PrimitiveType type, std::size_t firstVertex, std::size_t vertexCount)
{
// Find the OpenGL primitive type
static constexpr priv::EnumArray<PrimitiveType, GLenum, 6> modes =
{GL_POINTS, GL_LINES, GL_LINE_STRIP, GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN};
const GLenum mode = modes[type];
// Draw the primitives
glCheck(glDrawArrays(mode, static_cast<GLint>(firstVertex), static_cast<GLsizei>(vertexCount)));
}
////////////////////////////////////////////////////////////
void RenderTarget::cleanupDraw(const RenderStates& states)
{
// Unbind the shader, if any
if (states.shader)
applyShader(nullptr);
// If the texture we used to draw belonged to a RenderTexture, then forcibly unbind that texture.
// This prevents a bug where some drivers do not clear RenderTextures properly.
if (states.texture && states.texture->m_fboAttachment)
applyTexture(nullptr);
// Mask the color buffer back on if necessary
if (states.stencilMode.stencilOnly)
glCheck(glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE));
// Re-enable the cache at the end of the draw if it was disabled
m_cache.enable = true;
}
} // namespace sf
////////////////////////////////////////////////////////////
// Render states caching strategies
//
// * View
// If SetView was called since last draw, the projection
// matrix is updated. We don't need more, the view doesn't
// change frequently.
//
// * Transform
// The transform matrix is usually expensive because each
// entity will most likely use a different transform. This can
// lead, in worst case, to changing it every 4 vertices.
// To avoid that, when the vertex count is low enough, we
// pre-transform them and therefore use an identity transform
// to render them.
//
// * Blending mode
// 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
// is not enough; if the sf::Texture instance is destroyed,
// both the pointer and the OpenGL ID might be recycled in
// a new texture instance. We need to use our own unique
// identifier system to ensure consistent caching.
//
// * Shader
// Shaders are very hard to optimize, because they have
// parameters that can be hard (if not impossible) to track,
// like matrices or textures. The only optimization that we
// do is that we avoid setting a null shader if there was
// already none for the previous draw.
//
////////////////////////////////////////////////////////////