Upload BSP tree to the GPU

src/CMakeLists.txt

@@ -939,6 +939,7 @@ set( FASTMATH_SOURCES
 	gl/dynlights/gl_glow.cpp
 	gl/dynlights/gl_dynlight1.cpp
 	gl/dynlights/gl_lightbuffer.cpp
+	gl/dynlights/gl_lightbsp.cpp
 	gl/shaders/gl_shader.cpp
 	gl/shaders/gl_texshader.cpp
 	gl/shaders/gl_shaderprogram.cpp

src/gl/dynlights/gl_lightbsp.cpp

@@ -0,0 +1,167 @@
+// 
+//---------------------------------------------------------------------------
+// Doom BSP tree on the GPU
+// Copyright(C) 2017 Magnus Norddahl
+// 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/
+//
+//--------------------------------------------------------------------------
+//
+
+#include "gl/system/gl_system.h"
+#include "gl/shaders/gl_shader.h"
+#include "gl/dynlights/gl_lightbsp.h"
+#include "gl/system/gl_interface.h"
+#include "r_state.h"
+
+int FLightBSP::GetNodesBuffer()
+{
+	UpdateBuffers();
+	return NodesBuffer;
+}
+
+int FLightBSP::GetSegsBuffer()
+{
+	UpdateBuffers();
+	return SegsBuffer;
+}
+
+void FLightBSP::UpdateBuffers()
+{
+	if (numnodes != NumNodes || numsegs != NumSegs) // To do: there is probably a better way to detect a map change than this..
+		Clear();
+
+	if (NodesBuffer == 0)
+		GenerateBuffers();
+}
+
+void FLightBSP::GenerateBuffers()
+{
+	UploadNodes();
+	UploadSegs();
+}
+
+void FLightBSP::UploadNodes()
+{
+	TArray<GPUNode> gpunodes;
+	gpunodes.Resize(numnodes);
+	for (int i = 0; i < numnodes; i++)
+	{
+		const auto &node = nodes[i];
+		auto &gpunode = gpunodes[i];
+
+		float a = -FIXED2FLOAT(node.dy);
+		float b = FIXED2FLOAT(node.dx);
+		float c = 0.0f;
+		float d = -(a * FIXED2FLOAT(node.x) + b * FIXED2FLOAT(node.y));
+
+		gpunode.plane[0] = a;
+		gpunode.plane[1] = b;
+		gpunode.plane[2] = c;
+		gpunode.plane[3] = d;
+
+		for (int j = 0; j < 2; j++)
+		{
+			bool isNode = (!((size_t)node.children[j] & 1));
+			if (isNode)
+			{
+				node_t *bsp = (node_t *)node.children[j];
+				gpunode.children[j] = (int)(ptrdiff_t)(bsp - nodes);
+				gpunode.linecount[j] = -1;
+			}
+			else
+			{
+				subsector_t *sub = (subsector_t *)((BYTE *)node.children[j] - 1);
+				if (sub->numlines > 0)
+					gpunode.children[j] = (int)(ptrdiff_t)(sub->firstline - segs);
+				else
+					gpunode.children[j] = 0;
+				gpunode.linecount[j] = sub->numlines;
+			}
+		}
+	}
+
+#if 0
+	if (gpunodes.Size() > 0)
+	{
+		FILE *file = fopen("nodes.txt", "wb");
+		fwrite(&gpunodes[0], sizeof(GPUNode) * gpunodes.Size(), 1, file);
+		fclose(file);
+	}
+#endif
+
+	int oldBinding = 0;
+	glGetIntegerv(GL_SHADER_STORAGE_BUFFER_BINDING, &oldBinding);
+
+	glGenBuffers(1, (GLuint*)&NodesBuffer);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, NodesBuffer);
+	glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(GPUNode) * gpunodes.Size(), &gpunodes[0], GL_STATIC_DRAW);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, oldBinding);
+
+	NumNodes = numnodes;
+}
+
+void FLightBSP::UploadSegs()
+{
+	TArray<GPUSeg> gpusegs;
+	gpusegs.Resize(numsegs);
+	for (int i = 0; i < numsegs; i++)
+	{
+		const auto &seg = segs[i];
+		auto &gpuseg = gpusegs[i];
+
+		gpuseg.x = (float)seg.v1->fX();
+		gpuseg.y = (float)seg.v1->fY();
+		gpuseg.dx = (float)seg.v2->fX() - gpuseg.x;
+		gpuseg.dy = (float)seg.v2->fY() - gpuseg.y;
+		gpuseg.bSolid = (seg.backsector == nullptr) ? 1.0f : 0.0f;
+		gpuseg.padding1 = 0.0f;
+		gpuseg.padding2 = 0.0f;
+		gpuseg.padding3 = 0.0f;
+	}
+
+#if 0
+	if (gpusegs.Size() > 0)
+	{
+		FILE *file = fopen("segs.txt", "wb");
+		fwrite(&gpusegs[0], sizeof(GPUSeg) * gpusegs.Size(), 1, file);
+		fclose(file);
+	}
+#endif
+
+	int oldBinding = 0;
+	glGetIntegerv(GL_SHADER_STORAGE_BUFFER_BINDING, &oldBinding);
+
+	glGenBuffers(1, (GLuint*)&SegsBuffer);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, SegsBuffer);
+	glBufferData(GL_SHADER_STORAGE_BUFFER, sizeof(GPUSeg) * gpusegs.Size(), &gpusegs[0], GL_STATIC_DRAW);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, oldBinding);
+
+	NumSegs = numsegs;
+}
+
+void FLightBSP::Clear()
+{
+	if (NodesBuffer != 0)
+	{
+		glDeleteBuffers(1, (GLuint*)&NodesBuffer);
+		NodesBuffer = 0;
+	}
+	if (SegsBuffer != 0)
+	{
+		glDeleteBuffers(1, (GLuint*)&SegsBuffer);
+		SegsBuffer = 0;
+	}
+}

src/gl/dynlights/gl_lightbsp.h

@@ -0,0 +1,42 @@
+
+#pragma once
+
+struct GPUNode
+{
+	float plane[4];
+	int children[2];
+	int linecount[2];
+};
+
+struct GPUSeg
+{
+	float x, y;
+	float dx, dy;
+	float bSolid;
+	float padding1, padding2, padding3;
+};
+
+class FLightBSP
+{
+public:
+	FLightBSP() { }
+	~FLightBSP() { Clear(); }
+
+	int GetNodesBuffer();
+	int GetSegsBuffer();
+	void Clear();
+
+private:
+	void UpdateBuffers();
+	void GenerateBuffers();
+	void UploadNodes();
+	void UploadSegs();
+
+	FLightBSP(const FLightBSP &) = delete;
+	FLightBSP &operator=(FLightBSP &) = delete;
+
+	int NodesBuffer = 0;
+	int SegsBuffer = 0;
+	int NumNodes = 0;
+	int NumSegs = 0;
+};

src/gl/renderer/gl_renderer.h

@@ -6,6 +6,7 @@
 #include "vectors.h"
 #include "r_renderer.h"
 #include "gl/data/gl_matrix.h"
+#include "gl/dynlights/gl_lightbsp.h"
 
 struct particle_t;
 class FCanvasTexture;
@@ -123,6 +124,8 @@ public:
 	FPresent3DColumnShader *mPresent3dColumnShader;
 	FPresent3DRowShader *mPresent3dRowShader;
 
+	FLightBSP mLightBSP;
+
 	FTexture *gllight;
 	FTexture *glpart2;
 	FTexture *glpart;