vkdoom_m/src/rendering/gl/system/gl_framebuffer.cpp

// 
//---------------------------------------------------------------------------
//
// Copyright(C) 2010-2016 Christoph Oelckers
// All rights reserved.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see http://www.gnu.org/licenses/
//
//--------------------------------------------------------------------------
//
/*
** gl_framebuffer.cpp
** Implementation of the non-hardware specific parts of the
** OpenGL frame buffer
**
*/

#include "gl_system.h"
#include "v_video.h"
#include "m_png.h"
#include "templates.h"
#include "i_time.h"

#include "gl_interface.h"
#include "gl/system/gl_framebuffer.h"
#include "gl/renderer/gl_renderer.h"
#include "gl/renderer/gl_renderbuffers.h"
#include "gl/textures/gl_samplers.h"
#include "hwrenderer/utility/hw_clock.h"
#include "hwrenderer/utility/hw_vrmodes.h"
#include "hwrenderer/models/hw_models.h"
#include "hwrenderer/scene/hw_skydome.h"
#include "hwrenderer/scene/hw_fakeflat.h"
#include "hwrenderer/data/hw_viewpointbuffer.h"
#include "hwrenderer/dynlights/hw_lightbuffer.h"
#include "gl/shaders/gl_shaderprogram.h"
#include "gl_debug.h"
#include "r_videoscale.h"
#include "gl_buffers.h"
#include "swrenderer/r_swscene.h"

#include "hwrenderer/data/flatvertices.h"

EXTERN_CVAR (Bool, vid_vsync)
EXTERN_CVAR(Bool, r_drawvoxels)
EXTERN_CVAR(Int, gl_tonemap)
EXTERN_CVAR(Bool, cl_capfps)

void DoWriteSavePic(FileWriter* file, ESSType ssformat, uint8_t* scr, int width, int height, sector_t* viewsector, bool upsidedown);

extern bool NoInterpolateView;

void gl_LoadExtensions();
void gl_PrintStartupLog();
void Draw2D(F2DDrawer *drawer, FRenderState &state);

extern bool vid_hdr_active;

namespace OpenGLRenderer
{
	FGLRenderer *GLRenderer;

//==========================================================================
//
//
//
//==========================================================================

OpenGLFrameBuffer::OpenGLFrameBuffer(void *hMonitor, bool fullscreen) : 
	Super(hMonitor, fullscreen) 
{
	// SetVSync needs to be at the very top to workaround a bug in Nvidia's OpenGL driver.
	// If wglSwapIntervalEXT is called after glBindFramebuffer in a frame the setting is not changed!
	Super::SetVSync(vid_vsync);

	// Make sure all global variables tracking OpenGL context state are reset..
	FHardwareTexture::InitGlobalState();
	gl_RenderState.Reset();

	GLRenderer = nullptr;
}

OpenGLFrameBuffer::~OpenGLFrameBuffer()
{
	PPResource::ResetAll();

	if (mVertexData != nullptr) delete mVertexData;
	if (mSkyData != nullptr) delete mSkyData;
	if (mViewpoints != nullptr) delete mViewpoints;
	if (mLights != nullptr) delete mLights;
	mShadowMap.Reset();

	if (GLRenderer)
	{
		delete GLRenderer;
		GLRenderer = nullptr;
	}
}

//==========================================================================
//
// Initializes the GL renderer
//
//==========================================================================

void OpenGLFrameBuffer::InitializeState()
{
	static bool first=true;

	if (first)
	{
		if (ogl_LoadFunctions() == ogl_LOAD_FAILED)
		{
			I_FatalError("Failed to load OpenGL functions.");
		}
	}

	gl_LoadExtensions();

	// Move some state to the framebuffer object for easier access.
	hwcaps = gl.flags;
	glslversion = gl.glslversion;
	uniformblockalignment = gl.uniformblockalignment;
	maxuniformblock = gl.maxuniformblock;
	vendorstring = gl.vendorstring;

	if (first)
	{
		first=false;
		gl_PrintStartupLog();
	}

	glDepthFunc(GL_LESS);

	glEnable(GL_DITHER);
	glDisable(GL_CULL_FACE);
	glDisable(GL_POLYGON_OFFSET_FILL);
	glEnable(GL_POLYGON_OFFSET_LINE);
	glEnable(GL_BLEND);
	glEnable(GL_DEPTH_CLAMP);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_LINE_SMOOTH);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	SetViewportRects(nullptr);

	mVertexData = new FFlatVertexBuffer(GetWidth(), GetHeight());
	mSkyData = new FSkyVertexBuffer;
	mViewpoints = new HWViewpointBuffer;
	mLights = new FLightBuffer();

	GLRenderer = new FGLRenderer(this);
	GLRenderer->Initialize(GetWidth(), GetHeight());

	static_cast<GLDataBuffer*>(mLights->GetBuffer())->BindBase();

	mDebug = std::make_shared<FGLDebug>();
	mDebug->Update();
}

//==========================================================================
//
// Updates the screen
//
//==========================================================================

void OpenGLFrameBuffer::Update()
{
	twoD.Reset();
	Flush3D.Reset();

	Flush3D.Clock();
	GLRenderer->Flush();
	Flush3D.Unclock();

	Swap();
	Super::Update();
}

//===========================================================================
//
// Render the view to a savegame picture
//
//===========================================================================

void OpenGLFrameBuffer::WriteSavePic(player_t *player, FileWriter *file, int width, int height)
{
	if (!V_IsHardwareRenderer())
	{
		Super::WriteSavePic(player, file, width, height);
	}
	else if (GLRenderer != nullptr)
	{
		IntRect bounds;
		bounds.left = 0;
		bounds.top = 0;
		bounds.width = width;
		bounds.height = height;

		// we must be sure the GPU finished reading from the buffer before we fill it with new data.
		glFinish();

		// Switch to render buffers dimensioned for the savepic
		GLRenderer->mBuffers = GLRenderer->mSaveBuffers;

		hw_ClearFakeFlat();
		gl_RenderState.SetVertexBuffer(screen->mVertexData);
		screen->mVertexData->Reset();
		screen->mLights->Clear();
		screen->mViewpoints->Clear();

		// This shouldn't overwrite the global viewpoint even for a short time.
		FRenderViewpoint savevp;
		sector_t* viewsector = RenderViewpoint(savevp, players[consoleplayer].camera, &bounds, r_viewpoint.FieldOfView.Degrees, 1.6f, 1.6f, true, false);
		glDisable(GL_STENCIL_TEST);
		gl_RenderState.SetNoSoftLightLevel();
		GLRenderer->CopyToBackbuffer(&bounds, false);

		// strictly speaking not needed as the glReadPixels should block until the scene is rendered, but this is to safeguard against shitty drivers
		glFinish();

		int numpixels = width * height;
		uint8_t* scr = (uint8_t*)M_Malloc(numpixels * 3);
		glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, scr);

		DoWriteSavePic(file, SS_RGB, scr, width, height, viewsector, true);
		M_Free(scr);

		// Switch back the screen render buffers
		screen->SetViewportRects(nullptr);
		GLRenderer->mBuffers = GLRenderer->mScreenBuffers;
	}
}

//===========================================================================
//
// Camera texture rendering
//
//===========================================================================

void OpenGLFrameBuffer::RenderTextureView(FCanvasTexture* tex, AActor* Viewpoint, double FOV)
{
	// This doesn't need to clear the fake flat cache. It can be shared between camera textures and the main view of a scene.

	float ratio = tex->aspectRatio;

	GLRenderer->StartOffscreen();
	GLRenderer->BindToFrameBuffer(tex);

	IntRect bounds;
	bounds.left = bounds.top = 0;
	bounds.width = FHardwareTexture::GetTexDimension(tex->GetWidth());
	bounds.height = FHardwareTexture::GetTexDimension(tex->GetHeight());

	FRenderViewpoint texvp;
	RenderViewpoint(texvp, Viewpoint, &bounds, FOV, ratio, ratio, false, false);

	GLRenderer->EndOffscreen();

	tex->SetUpdated(true);
	static_cast<OpenGLFrameBuffer*>(screen)->camtexcount++;
}

//===========================================================================
//
// 
//
//===========================================================================

sector_t *OpenGLFrameBuffer::RenderView(player_t *player)
{
	if (GLRenderer != nullptr)
	{
		gl_RenderState.SetVertexBuffer(screen->mVertexData);
		screen->mVertexData->Reset();
		sector_t* retsec;

		if (!V_IsHardwareRenderer())
		{
			if (GLRenderer->swdrawer == nullptr) GLRenderer->swdrawer = new SWSceneDrawer;
			retsec = GLRenderer->swdrawer->RenderView(player);
		}
		else
		{
			hw_ClearFakeFlat();

			iter_dlightf = iter_dlight = draw_dlight = draw_dlightf = 0;

			checkBenchActive();

			// reset statistics counters
			ResetProfilingData();

			// Get this before everything else
			if (cl_capfps || r_NoInterpolate) r_viewpoint.TicFrac = 1.;
			else r_viewpoint.TicFrac = I_GetTimeFrac();

			screen->mLights->Clear();
			screen->mViewpoints->Clear();

			// NoInterpolateView should have no bearing on camera textures, but needs to be preserved for the main view below.
			bool saved_niv = NoInterpolateView;
			NoInterpolateView = false;

			// Shader start time does not need to be handled per level. Just use the one from the camera to render from.
			if (player->camera)
				gl_RenderState.CheckTimer(player->camera->Level->ShaderStartTime);
			// prepare all camera textures that have been used in the last frame.
			// This must be done for all levels, not just the primary one!
			for (auto Level : AllLevels())
			{
				Level->canvasTextureInfo.UpdateAll([&](AActor* camera, FCanvasTexture* camtex, double fov)
					{
						RenderTextureView(camtex, camera, fov);
					});
			}
			NoInterpolateView = saved_niv;


			// now render the main view
			float fovratio;
			float ratio = r_viewwindow.WidescreenRatio;
			if (r_viewwindow.WidescreenRatio >= 1.3f)
			{
				fovratio = 1.333333f;
			}
			else
			{
				fovratio = ratio;
			}

			retsec = RenderViewpoint(r_viewpoint, player->camera, NULL, r_viewpoint.FieldOfView.Degrees, ratio, fovratio, true, true);
		}
		All.Unclock();
		return retsec;
	}
	return nullptr;
}



//===========================================================================
//
// 
//
//===========================================================================

uint32_t OpenGLFrameBuffer::GetCaps()
{
	if (!V_IsHardwareRenderer())
		return Super::GetCaps();

	// describe our basic feature set
	ActorRenderFeatureFlags FlagSet = RFF_FLATSPRITES | RFF_MODELS | RFF_SLOPE3DFLOORS |
		RFF_TILTPITCH | RFF_ROLLSPRITES | RFF_POLYGONAL | RFF_MATSHADER | RFF_POSTSHADER | RFF_BRIGHTMAP;
	if (r_drawvoxels)
		FlagSet |= RFF_VOXELS;

	if (gl_tonemap != 5) // not running palette tonemap shader
		FlagSet |= RFF_TRUECOLOR;

	return (uint32_t)FlagSet;
}

const char* OpenGLFrameBuffer::DeviceName() const 
{
	return gl.modelstring;
}

//==========================================================================
//
// Swap the buffers
//
//==========================================================================

CVAR(Bool, gl_finishbeforeswap, false, CVAR_ARCHIVE|CVAR_GLOBALCONFIG);

void OpenGLFrameBuffer::Swap()
{
	bool swapbefore = gl_finishbeforeswap && camtexcount == 0;
	Finish.Reset();
	Finish.Clock();
	if (swapbefore) glFinish();
	FPSLimit();
	SwapBuffers();
	if (!swapbefore) glFinish();
	Finish.Unclock();
	camtexcount = 0;
	FHardwareTexture::UnbindAll();
	mDebug->Update();
}

//==========================================================================
//
// Enable/disable vertical sync
//
//==========================================================================

void OpenGLFrameBuffer::SetVSync(bool vsync)
{
	// Switch to the default frame buffer because some drivers associate the vsync state with the bound FB object.
	GLint oldDrawFramebufferBinding = 0, oldReadFramebufferBinding = 0;
	glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &oldDrawFramebufferBinding);
	glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING, &oldReadFramebufferBinding);
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
	glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);

	Super::SetVSync(vsync);

	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, oldDrawFramebufferBinding);
	glBindFramebuffer(GL_READ_FRAMEBUFFER, oldReadFramebufferBinding);
}

//===========================================================================
//
//
//===========================================================================

void OpenGLFrameBuffer::CleanForRestart()
{
	if (GLRenderer)
		GLRenderer->ResetSWScene();
}

void OpenGLFrameBuffer::SetTextureFilterMode()
{
	if (GLRenderer != nullptr && GLRenderer->mSamplerManager != nullptr) GLRenderer->mSamplerManager->SetTextureFilterMode();
}

IHardwareTexture *OpenGLFrameBuffer::CreateHardwareTexture() 
{ 
	return new FHardwareTexture(true/*tex->bNoCompress*/);
}

void OpenGLFrameBuffer::PrecacheMaterial(FMaterial *mat, int translation)
{
	if (mat->Source()->GetUseType() == ETextureType::SWCanvas) return;

	int flags = mat->GetScaleFlags();
	int numLayers = mat->NumLayers();
	MaterialLayerInfo* layer;
	auto base = static_cast<FHardwareTexture*>(mat->GetLayer(0, translation, &layer));

	if (base->BindOrCreate(layer->layerTexture, 0, CLAMP_NONE, translation, layer->scaleFlags))
	{
		for (int i = 1; i < numLayers; i++)
		{
			auto systex = static_cast<FHardwareTexture*>(mat->GetLayer(i, 0, &layer));
			systex->BindOrCreate(layer->layerTexture, i, CLAMP_NONE, 0, layer->scaleFlags);
		}
	}
	// unbind everything. 
	FHardwareTexture::UnbindAll();
}

FModelRenderer *OpenGLFrameBuffer::CreateModelRenderer(int mli)
{
	return new FHWModelRenderer(nullptr, gl_RenderState, mli);
}

IVertexBuffer *OpenGLFrameBuffer::CreateVertexBuffer()
{ 
	return new GLVertexBuffer; 
}

IIndexBuffer *OpenGLFrameBuffer::CreateIndexBuffer()
{ 
	return new GLIndexBuffer; 
}

IDataBuffer *OpenGLFrameBuffer::CreateDataBuffer(int bindingpoint, bool ssbo, bool needsresize)
{
	return new GLDataBuffer(bindingpoint, ssbo);
}

void OpenGLFrameBuffer::TextureFilterChanged()
{
	if (GLRenderer != NULL && GLRenderer->mSamplerManager != NULL) GLRenderer->mSamplerManager->SetTextureFilterMode();
}

void OpenGLFrameBuffer::BlurScene(float amount)
{
	GLRenderer->BlurScene(amount);
}

void OpenGLFrameBuffer::SetViewportRects(IntRect *bounds)
{
	Super::SetViewportRects(bounds);
	if (!bounds)
	{
		auto vrmode = VRMode::GetVRMode(true);
		vrmode->AdjustViewport(this);
	}
}

void OpenGLFrameBuffer::UpdatePalette()
{
	if (GLRenderer)
		GLRenderer->ClearTonemapPalette();
}

FRenderState* OpenGLFrameBuffer::RenderState()
{
	return &gl_RenderState;
}

void OpenGLFrameBuffer::AmbientOccludeScene(float m5)
{
	gl_RenderState.EnableDrawBuffers(1);
	GLRenderer->AmbientOccludeScene(m5);
	glViewport(screen->mSceneViewport.left, mSceneViewport.top, mSceneViewport.width, mSceneViewport.height);
	GLRenderer->mBuffers->BindSceneFB(true);
	gl_RenderState.EnableDrawBuffers(gl_RenderState.GetPassDrawBufferCount());
	gl_RenderState.Apply();
}

void OpenGLFrameBuffer::FirstEye()
{
	GLRenderer->mBuffers->CurrentEye() = 0;  // always begin at zero, in case eye count changed
}

void OpenGLFrameBuffer::NextEye(int eyecount)
{
	GLRenderer->mBuffers->NextEye(eyecount);
}

void OpenGLFrameBuffer::SetSceneRenderTarget(bool useSSAO)
{
	GLRenderer->mBuffers->BindSceneFB(useSSAO);
}

void OpenGLFrameBuffer::UpdateShadowMap()
{
	GLRenderer->UpdateShadowMap();
}

//===========================================================================
//
// 
//
//===========================================================================

void OpenGLFrameBuffer::BeginFrame()
{
	SetViewportRects(nullptr);
	if (GLRenderer != nullptr)
		GLRenderer->BeginFrame();
}

//===========================================================================
// 
//	Takes a screenshot
//
//===========================================================================

TArray<uint8_t> OpenGLFrameBuffer::GetScreenshotBuffer(int &pitch, ESSType &color_type, float &gamma)
{
	const auto &viewport = mOutputLetterbox;

	// Grab what is in the back buffer.
	// We cannot rely on SCREENWIDTH/HEIGHT here because the output may have been scaled.
	TArray<uint8_t> pixels;
	pixels.Resize(viewport.width * viewport.height * 3);
	glPixelStorei(GL_PACK_ALIGNMENT, 1);
	glReadPixels(viewport.left, viewport.top, viewport.width, viewport.height, GL_RGB, GL_UNSIGNED_BYTE, &pixels[0]);
	glPixelStorei(GL_PACK_ALIGNMENT, 4);

	// Copy to screenshot buffer:
	int w = SCREENWIDTH;
	int h = SCREENHEIGHT;

	TArray<uint8_t> ScreenshotBuffer(w * h * 3, true);

	float rcpWidth = 1.0f / w;
	float rcpHeight = 1.0f / h;
	for (int y = 0; y < h; y++)
	{
		for (int x = 0; x < w; x++)
		{
			float u = (x + 0.5f) * rcpWidth;
			float v = (y + 0.5f) * rcpHeight;
			int sx = u * viewport.width;
			int sy = v * viewport.height;
			int sindex = (sx + sy * viewport.width) * 3;
			int dindex = (x + (h - y - 1) * w) * 3;
			ScreenshotBuffer[dindex] = pixels[sindex];
			ScreenshotBuffer[dindex + 1] = pixels[sindex + 1];
			ScreenshotBuffer[dindex + 2] = pixels[sindex + 2];
		}
	}

	pitch = w * 3;
	color_type = SS_RGB;

	// Screenshot should not use gamma correction if it was already applied to rendered image
	gamma = 1;
	if (vid_hdr_active && vid_fullscreen)
		gamma *= 2.2f;
	return ScreenshotBuffer;
}

//===========================================================================
// 
// 2D drawing
//
//===========================================================================

void OpenGLFrameBuffer::Draw2D()
{
	if (GLRenderer != nullptr)
	{
		GLRenderer->mBuffers->BindCurrentFB();
		::Draw2D(&m2DDrawer, gl_RenderState);
	}
}

void OpenGLFrameBuffer::PostProcessScene(bool swscene, int fixedcm, const std::function<void()> &afterBloomDrawEndScene2D)
{
	if (!swscene) GLRenderer->mBuffers->BlitSceneToTexture(); // Copy the resulting scene to the current post process texture
	GLRenderer->PostProcessScene(fixedcm, afterBloomDrawEndScene2D);
}

//==========================================================================
//
// OpenGLFrameBuffer :: WipeStartScreen
//
// Called before the current screen has started rendering. This needs to
// save what was drawn the previous frame so that it can be animated into
// what gets drawn this frame.
//
//==========================================================================

FTexture *OpenGLFrameBuffer::WipeStartScreen()
{
	const auto &viewport = screen->mScreenViewport;

	auto tex = new FWrapperTexture(viewport.width, viewport.height, 1);
	tex->GetSystemTexture()->CreateTexture(nullptr, viewport.width, viewport.height, 0, false, "WipeStartScreen");
	glFinish();
	static_cast<FHardwareTexture*>(tex->GetSystemTexture())->Bind(0, false);

	GLRenderer->mBuffers->BindCurrentFB();
	glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, viewport.left, viewport.top, viewport.width, viewport.height);
	return tex;
}

//==========================================================================
//
// OpenGLFrameBuffer :: WipeEndScreen
//
// The screen we want to animate to has just been drawn.
//
//==========================================================================

FTexture *OpenGLFrameBuffer::WipeEndScreen()
{
	GLRenderer->Flush();
	const auto &viewport = screen->mScreenViewport;
	auto tex = new FWrapperTexture(viewport.width, viewport.height, 1);
	tex->GetSystemTexture()->CreateTexture(NULL, viewport.width, viewport.height, 0, false, "WipeEndScreen");
	glFinish();
	static_cast<FHardwareTexture*>(tex->GetSystemTexture())->Bind(0, false);
	GLRenderer->mBuffers->BindCurrentFB();
	glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, viewport.left, viewport.top, viewport.width, viewport.height);
	return tex;
}

}