1
0
Fork 0
mirror of https://github.com/juce-framework/JUCE.git synced 2026-01-10 23:44:24 +00:00
JUCE/modules/juce_opengl/opengl/juce_OpenGLFrameBuffer.cpp

535 lines
16 KiB
C++

/*
==============================================================================
This file is part of the JUCE framework.
Copyright (c) Raw Material Software Limited
JUCE is an open source framework subject to commercial or open source
licensing.
By downloading, installing, or using the JUCE framework, or combining the
JUCE framework with any other source code, object code, content or any other
copyrightable work, you agree to the terms of the JUCE End User Licence
Agreement, and all incorporated terms including the JUCE Privacy Policy and
the JUCE Website Terms of Service, as applicable, which will bind you. If you
do not agree to the terms of these agreements, we will not license the JUCE
framework to you, and you must discontinue the installation or download
process and cease use of the JUCE framework.
JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
JUCE Privacy Policy: https://juce.com/juce-privacy-policy
JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/
Or:
You may also use this code under the terms of the AGPLv3:
https://www.gnu.org/licenses/agpl-3.0.en.html
THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
==============================================================================
*/
namespace juce
{
class OpenGLFrameBuffer::Pimpl
{
public:
struct SavedState
{
int width = 0, height = 0;
std::vector<PixelARGB> data;
};
bool isValid() const noexcept
{
return std::holds_alternative<TransientState> (state);
}
bool initialise (OpenGLContext& context, int width, int height)
{
jassert (context.isActive()); // The context must be active when creating a framebuffer!
release();
auto& transientState = state.emplace<TransientState> (width, height, false, false);
if (! transientState.createdOk())
release();
if (! isValid())
return false;
associatedContext = &context;
return true;
}
bool initialise (OpenGLContext& context, const Image& image)
{
if (! image.isARGB())
return initialise (context, image.convertedToFormat (Image::ARGB));
Image::BitmapData bitmap (image, Image::BitmapData::readOnly);
return initialise (context, bitmap.width, bitmap.height)
&& writePixels ((const PixelARGB*) bitmap.data, image.getBounds());
}
bool initialise (OpenGLFrameBuffer& other)
{
auto* p = std::get_if<TransientState> (&other.pimpl->state);
if (p == nullptr || other.pimpl->associatedContext == nullptr)
{
release();
return true;
}
const Rectangle<int> area (p->width, p->height);
if (! initialise (*other.pimpl->associatedContext, area.getWidth(), area.getHeight()))
return false;
jassert (associatedContext != nullptr);
auto* transientState = std::get_if<TransientState> (&state);
transientState->bind();
#if ! JUCE_ANDROID
if (! associatedContext->isCoreProfile())
glEnable (GL_TEXTURE_2D);
clearGLError();
#endif
{
const ScopedTextureBinding scopedTextureBinding;
glBindTexture (GL_TEXTURE_2D, p->textureID);
associatedContext->copyTexture (area, area, area.getWidth(), area.getHeight(), false);
}
transientState->unbind();
return true;
}
void release()
{
associatedContext = nullptr;
state.emplace<std::monostate>();
}
void saveAndRelease()
{
if (auto* transientState = std::get_if<TransientState> (&state))
{
if (auto toSave = readPixels ({ transientState->width, transientState->height }))
state.emplace<SavedState> (std::move (*toSave));
}
}
bool reloadSavedCopy (OpenGLContext& context)
{
if (auto* savedState = std::get_if<SavedState> (&state))
{
auto local = std::move (*savedState);
if (restore (context, local))
return true;
state.emplace<SavedState> (std::move (local));
}
return false;
}
int getWidth() const noexcept
{
if (auto* transientState = std::get_if<TransientState> (&state))
return transientState->width;
return 0;
}
int getHeight() const noexcept
{
if (auto* transientState = std::get_if<TransientState> (&state))
return transientState->height;
return 0;
}
GLuint getTextureID() const noexcept
{
if (auto* transientState = std::get_if<TransientState> (&state))
return transientState->textureID;
return 0;
}
GLuint getFrameBufferID() const noexcept
{
if (auto* transientState = std::get_if<TransientState> (&state))
return transientState->frameBufferID;
return 0;
}
bool makeCurrentRenderingTarget()
{
return makeAndGetCurrentRenderingTarget() != nullptr;
}
void releaseAsRenderingTarget()
{
if (auto* transientState = std::get_if<TransientState> (&state))
transientState->unbind();
}
void clear (Colour colour)
{
auto* transientState = makeAndGetCurrentRenderingTarget();
if (transientState == nullptr)
return;
OpenGLHelpers::clear (colour);
transientState->unbind();
}
void makeCurrentAndClear()
{
auto* transientState = makeAndGetCurrentRenderingTarget();
if (transientState == nullptr)
return;
glClearColor (0, 0, 0, 0);
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
}
bool readPixels (PixelARGB* target, const Rectangle<int>& area)
{
auto* transientState = makeAndGetCurrentRenderingTarget();
if (transientState == nullptr)
return false;
glPixelStorei (GL_PACK_ALIGNMENT, 4);
glReadPixels (area.getX(), area.getY(), area.getWidth(), area.getHeight(),
JUCE_RGBA_FORMAT, GL_UNSIGNED_BYTE, target);
transientState->unbind();
return true;
}
bool writePixels (const PixelARGB* data, const Rectangle<int>& area)
{
if (associatedContext == nullptr)
return false;
const OpenGLTargetSaver ts;
auto* transientState = makeAndGetCurrentRenderingTarget();
if (transientState == nullptr)
return false;
glDisable (GL_DEPTH_TEST);
glDisable (GL_BLEND);
JUCE_CHECK_OPENGL_ERROR
OpenGLTexture tex;
tex.loadARGB (data, area.getWidth(), area.getHeight());
glViewport (0, 0, transientState->width, transientState->height);
associatedContext->copyTexture (area,
Rectangle<int> (area.getX(),
area.getY(),
tex.getWidth(),
tex.getHeight()),
transientState->width,
transientState->height,
true,
false);
JUCE_CHECK_OPENGL_ERROR
return true;
}
private:
/* Stores the currently-bound texture on construction, and re-binds it on destruction. */
struct ScopedTextureBinding
{
ScopedTextureBinding()
{
glGetIntegerv (GL_TEXTURE_BINDING_2D, &prev);
JUCE_CHECK_OPENGL_ERROR
}
~ScopedTextureBinding()
{
glBindTexture (GL_TEXTURE_2D, (GLuint) prev);
JUCE_CHECK_OPENGL_ERROR
}
GLint prev{};
};
class TransientState
{
public:
TransientState (const int w,
const int h,
const bool wantsDepthBuffer,
const bool wantsStencilBuffer)
: width (w),
height (h),
textureID (0),
frameBufferID (0),
depthOrStencilBuffer (0)
{
// Framebuffer objects can only be created when the current thread has an active OpenGL
// context. You'll need to create this object in one of the OpenGLContext's callbacks.
jassert (OpenGLHelpers::isContextActive());
#if JUCE_WINDOWS || JUCE_LINUX || JUCE_BSD
if (gl::glGenFramebuffers == nullptr)
return;
#endif
gl::glGenFramebuffers (1, &frameBufferID);
bind();
{
const ScopedTextureBinding scopedTextureBinding;
glGenTextures (1, &textureID);
glBindTexture (GL_TEXTURE_2D, textureID);
JUCE_CHECK_OPENGL_ERROR
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
JUCE_CHECK_OPENGL_ERROR
glTexImage2D (GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
JUCE_CHECK_OPENGL_ERROR
}
gl::glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureID, 0);
if (wantsDepthBuffer || wantsStencilBuffer)
{
gl::glGenRenderbuffers (1, &depthOrStencilBuffer);
gl::glBindRenderbuffer (GL_RENDERBUFFER, depthOrStencilBuffer);
jassert (gl::glIsRenderbuffer (depthOrStencilBuffer));
#if JUCE_OPENGL_ES
constexpr auto depthComponentConstant = (GLenum) GL_DEPTH_COMPONENT16;
#else
constexpr auto depthComponentConstant = (GLenum) GL_DEPTH_COMPONENT;
#endif
gl::glRenderbufferStorage (GL_RENDERBUFFER,
(wantsDepthBuffer && wantsStencilBuffer) ? (GLenum) GL_DEPTH24_STENCIL8
: depthComponentConstant,
width,
height);
GLint params = 0;
gl::glGetRenderbufferParameteriv (GL_RENDERBUFFER, GL_RENDERBUFFER_DEPTH_SIZE, &params);
gl::glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthOrStencilBuffer);
if (wantsStencilBuffer)
gl::glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, depthOrStencilBuffer);
}
unbind();
}
~TransientState()
{
if (OpenGLHelpers::isContextActive())
{
if (textureID != 0)
glDeleteTextures (1, &textureID);
if (depthOrStencilBuffer != 0)
gl::glDeleteRenderbuffers (1, &depthOrStencilBuffer);
if (frameBufferID != 0)
gl::glDeleteFramebuffers (1, &frameBufferID);
JUCE_CHECK_OPENGL_ERROR
}
}
bool createdOk() const
{
return frameBufferID != 0 && textureID != 0;
}
void bind()
{
glGetIntegerv (GL_FRAMEBUFFER_BINDING, &prevFramebuffer);
gl::glBindFramebuffer (GL_FRAMEBUFFER, frameBufferID);
JUCE_CHECK_OPENGL_ERROR
}
void unbind()
{
gl::glBindFramebuffer (GL_FRAMEBUFFER, (GLuint) prevFramebuffer);
JUCE_CHECK_OPENGL_ERROR
}
const int width, height;
GLuint textureID, frameBufferID, depthOrStencilBuffer;
private:
GLint prevFramebuffer{};
JUCE_DECLARE_NON_COPYABLE (TransientState)
};
bool restore (OpenGLContext& context, const SavedState& savedState)
{
if (! initialise (context, savedState.width, savedState.height))
return false;
writePixels (savedState.data.data(), Rectangle (savedState.width, savedState.height));
return true;
}
std::optional<SavedState> readPixels (const Rectangle<int>& area)
{
SavedState result { area.getWidth(),
area.getHeight(),
std::vector<PixelARGB> ((size_t) area.getWidth() * (size_t) area.getHeight()) };
if (! readPixels (result.data.data(), area))
return {};
return result;
}
TransientState* makeAndGetCurrentRenderingTarget()
{
if (auto* transientState = std::get_if<TransientState> (&state))
{
transientState->bind();
return transientState;
}
// trying to use a framebuffer after saving it with saveAndRelease()! Be sure to call
// reloadSavedCopy() to put it back into GPU memory before using it..
jassertfalse;
return nullptr;
}
OpenGLContext* associatedContext = nullptr;
std::variant<std::monostate, TransientState, SavedState> state;
};
//==============================================================================
OpenGLFrameBuffer::OpenGLFrameBuffer()
: pimpl (std::make_unique<Pimpl>())
{
}
OpenGLFrameBuffer::~OpenGLFrameBuffer() = default;
bool OpenGLFrameBuffer::initialise (OpenGLContext& context, int width, int height)
{
return pimpl->initialise (context, width, height);
}
bool OpenGLFrameBuffer::initialise (OpenGLContext& context, const Image& content)
{
return pimpl->initialise (context, content);
}
bool OpenGLFrameBuffer::initialise (OpenGLFrameBuffer& other)
{
return pimpl->initialise (other);
}
void OpenGLFrameBuffer::release()
{
pimpl->release();
}
void OpenGLFrameBuffer::saveAndRelease()
{
pimpl->saveAndRelease();
}
bool OpenGLFrameBuffer::reloadSavedCopy (OpenGLContext& context)
{
return pimpl->reloadSavedCopy (context);
}
bool OpenGLFrameBuffer::isValid() const noexcept
{
return pimpl->isValid();
}
int OpenGLFrameBuffer::getWidth() const noexcept
{
return pimpl->getWidth();
}
int OpenGLFrameBuffer::getHeight() const noexcept
{
return pimpl->getHeight();
}
GLuint OpenGLFrameBuffer::getTextureID() const noexcept
{
return pimpl->getTextureID();
}
bool OpenGLFrameBuffer::makeCurrentRenderingTarget()
{
return pimpl->makeCurrentRenderingTarget();
}
void OpenGLFrameBuffer::releaseAsRenderingTarget()
{
pimpl->releaseAsRenderingTarget();
}
GLuint OpenGLFrameBuffer::getFrameBufferID() const noexcept
{
return pimpl->getFrameBufferID();
}
void OpenGLFrameBuffer::clear (Colour colour)
{
pimpl->clear (colour);
}
void OpenGLFrameBuffer::makeCurrentAndClear()
{
pimpl->makeCurrentAndClear();
}
bool OpenGLFrameBuffer::readPixels (PixelARGB* targetData, const Rectangle<int>& sourceArea)
{
return pimpl->readPixels (targetData, sourceArea);
}
bool OpenGLFrameBuffer::writePixels (const PixelARGB* srcData, const Rectangle<int>& targetArea)
{
return pimpl->writePixels (srcData, targetArea);
}
GLuint OpenGLFrameBuffer::getCurrentFrameBufferTarget() noexcept
{
GLint fb = {};
glGetIntegerv (GL_FRAMEBUFFER_BINDING, &fb);
return (GLuint) fb;
}
} // namespace juce