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JUCE/modules/juce_opengl/opengl/juce_OpenGLFrameBuffer.cpp
2024-04-16 11:39:35 +01:00

365 lines
12 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:
Pimpl (OpenGLContext& c, const int w, const int h,
const bool wantsDepthBuffer, const bool wantsStencilBuffer)
: context (c), width (w), height (h),
textureID (0), frameBufferID (0), depthOrStencilBuffer (0),
hasDepthBuffer (false), hasStencilBuffer (false)
{
// 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 (context.extensions.glGenFramebuffers == nullptr)
return;
#endif
context.extensions.glGenFramebuffers (1, &frameBufferID);
bind();
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
context.extensions.glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textureID, 0);
if (wantsDepthBuffer || wantsStencilBuffer)
{
context.extensions.glGenRenderbuffers (1, &depthOrStencilBuffer);
context.extensions.glBindRenderbuffer (GL_RENDERBUFFER, depthOrStencilBuffer);
jassert (context.extensions.glIsRenderbuffer (depthOrStencilBuffer));
context.extensions.glRenderbufferStorage (GL_RENDERBUFFER,
(wantsDepthBuffer && wantsStencilBuffer) ? (GLenum) GL_DEPTH24_STENCIL8
#if JUCE_OPENGL_ES
: (GLenum) GL_DEPTH_COMPONENT16,
#else
: (GLenum) GL_DEPTH_COMPONENT,
#endif
width, height);
GLint params = 0;
context.extensions.glGetRenderbufferParameteriv (GL_RENDERBUFFER, GL_RENDERBUFFER_DEPTH_SIZE, &params);
context.extensions.glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthOrStencilBuffer);
if (wantsStencilBuffer)
context.extensions.glFramebufferRenderbuffer (GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, depthOrStencilBuffer);
hasDepthBuffer = wantsDepthBuffer;
hasStencilBuffer = wantsStencilBuffer;
}
unbind();
}
~Pimpl()
{
if (OpenGLHelpers::isContextActive())
{
if (textureID != 0)
glDeleteTextures (1, &textureID);
if (depthOrStencilBuffer != 0)
context.extensions.glDeleteRenderbuffers (1, &depthOrStencilBuffer);
if (frameBufferID != 0)
context.extensions.glDeleteFramebuffers (1, &frameBufferID);
JUCE_CHECK_OPENGL_ERROR
}
}
bool createdOk() const
{
return frameBufferID != 0 && textureID != 0;
}
void bind()
{
context.extensions.glBindFramebuffer (GL_FRAMEBUFFER, frameBufferID);
JUCE_CHECK_OPENGL_ERROR
}
void unbind()
{
context.extensions.glBindFramebuffer (GL_FRAMEBUFFER, context.getFrameBufferID());
JUCE_CHECK_OPENGL_ERROR
}
OpenGLContext& context;
const int width, height;
GLuint textureID, frameBufferID, depthOrStencilBuffer;
bool hasDepthBuffer, hasStencilBuffer;
private:
bool checkStatus() noexcept
{
const GLenum status = context.extensions.glCheckFramebufferStatus (GL_FRAMEBUFFER);
return status == GL_NO_ERROR
|| status == GL_FRAMEBUFFER_COMPLETE;
}
JUCE_DECLARE_NON_COPYABLE (Pimpl)
};
//==============================================================================
class OpenGLFrameBuffer::SavedState
{
public:
SavedState (OpenGLFrameBuffer& buffer, const int w, const int h)
: width (w), height (h),
data ((size_t) (w * h))
{
buffer.readPixels (data, Rectangle<int> (w, h));
}
bool restore (OpenGLContext& context, OpenGLFrameBuffer& buffer)
{
if (buffer.initialise (context, width, height))
{
buffer.writePixels (data, Rectangle<int> (width, height));
return true;
}
return false;
}
private:
const int width, height;
HeapBlock<PixelARGB> data;
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (SavedState)
};
//==============================================================================
OpenGLFrameBuffer::OpenGLFrameBuffer() {}
OpenGLFrameBuffer::~OpenGLFrameBuffer() {}
bool OpenGLFrameBuffer::initialise (OpenGLContext& context, int width, int height)
{
jassert (context.isActive()); // The context must be active when creating a framebuffer!
pimpl.reset();
pimpl.reset (new Pimpl (context, width, height, false, false));
if (! pimpl->createdOk())
pimpl.reset();
return pimpl != nullptr;
}
bool OpenGLFrameBuffer::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 OpenGLFrameBuffer::initialise (OpenGLFrameBuffer& other)
{
auto* p = other.pimpl.get();
if (p == nullptr)
{
pimpl.reset();
return true;
}
const Rectangle<int> area (pimpl->width, pimpl->height);
if (initialise (p->context, area.getWidth(), area.getHeight()))
{
pimpl->bind();
#if ! JUCE_ANDROID
if (! pimpl->context.isCoreProfile())
glEnable (GL_TEXTURE_2D);
clearGLError();
#endif
glBindTexture (GL_TEXTURE_2D, p->textureID);
pimpl->context.copyTexture (area, area, area.getWidth(), area.getHeight(), false);
glBindTexture (GL_TEXTURE_2D, 0);
JUCE_CHECK_OPENGL_ERROR
pimpl->unbind();
return true;
}
return false;
}
void OpenGLFrameBuffer::release()
{
pimpl.reset();
savedState.reset();
}
void OpenGLFrameBuffer::saveAndRelease()
{
if (pimpl != nullptr)
{
savedState.reset (new SavedState (*this, pimpl->width, pimpl->height));
pimpl.reset();
}
}
bool OpenGLFrameBuffer::reloadSavedCopy (OpenGLContext& context)
{
if (savedState != nullptr)
{
std::unique_ptr<SavedState> state;
std::swap (state, savedState);
if (state->restore (context, *this))
return true;
std::swap (state, savedState);
}
return false;
}
int OpenGLFrameBuffer::getWidth() const noexcept { return pimpl != nullptr ? pimpl->width : 0; }
int OpenGLFrameBuffer::getHeight() const noexcept { return pimpl != nullptr ? pimpl->height : 0; }
GLuint OpenGLFrameBuffer::getTextureID() const noexcept { return pimpl != nullptr ? pimpl->textureID : 0; }
bool OpenGLFrameBuffer::makeCurrentRenderingTarget()
{
// 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..
jassert (savedState == nullptr);
if (pimpl == nullptr)
return false;
pimpl->bind();
return true;
}
GLuint OpenGLFrameBuffer::getFrameBufferID() const noexcept
{
return pimpl != nullptr ? pimpl->frameBufferID : 0;
}
GLuint OpenGLFrameBuffer::getCurrentFrameBufferTarget() noexcept
{
GLint fb = {};
glGetIntegerv (GL_FRAMEBUFFER_BINDING, &fb);
return (GLuint) fb;
}
void OpenGLFrameBuffer::releaseAsRenderingTarget()
{
if (pimpl != nullptr)
pimpl->unbind();
}
void OpenGLFrameBuffer::clear (Colour colour)
{
if (makeCurrentRenderingTarget())
{
OpenGLHelpers::clear (colour);
releaseAsRenderingTarget();
}
}
void OpenGLFrameBuffer::makeCurrentAndClear()
{
if (makeCurrentRenderingTarget())
{
glClearColor (0, 0, 0, 0);
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
}
}
bool OpenGLFrameBuffer::readPixels (PixelARGB* target, const Rectangle<int>& area)
{
if (! makeCurrentRenderingTarget())
return false;
glPixelStorei (GL_PACK_ALIGNMENT, 4);
glReadPixels (area.getX(), area.getY(), area.getWidth(), area.getHeight(),
JUCE_RGBA_FORMAT, GL_UNSIGNED_BYTE, target);
pimpl->unbind();
return true;
}
bool OpenGLFrameBuffer::writePixels (const PixelARGB* data, const Rectangle<int>& area)
{
OpenGLTargetSaver ts (pimpl->context);
if (! makeCurrentRenderingTarget())
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, pimpl->width, pimpl->height);
pimpl->context.copyTexture (area, Rectangle<int> (area.getX(), area.getY(),
tex.getWidth(), tex.getHeight()),
pimpl->width, pimpl->height, true);
JUCE_CHECK_OPENGL_ERROR
return true;
}
} // namespace juce