- use client arrays on compatibility profiles instead of calling glBegin/glEnd.

This eliminates most behavioral differences for FFlatVertexBuffer between both operating modes, now the only difference is where the buffer is located.

src/gl/data/gl_vertexbuffer.cpp

@@ -78,9 +78,9 @@ FVertexBuffer::~FVertexBuffer()
 //==========================================================================
 
 FFlatVertexBuffer::FFlatVertexBuffer()
-: FVertexBuffer(!!(gl.flags & RFL_BUFFER_STORAGE))
+: FVertexBuffer(gl.buffermethod == BM_PERSISTENT)
 {
-	if (gl.flags & RFL_BUFFER_STORAGE)
+	if (gl.buffermethod == BM_PERSISTENT)
 	{
 		unsigned int bytesize = BUFFER_SIZE * sizeof(FFlatVertex);
 		glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
@@ -91,19 +91,24 @@ FFlatVertexBuffer::FFlatVertexBuffer()
 	{
 		// The fallback path uses immediate mode rendering and does not set up an actual vertex buffer
 		vbo_shadowdata.Reserve(BUFFER_SIZE);
-		map = &vbo_shadowdata[0];
+		map = new FFlatVertex[BUFFER_SIZE];
 	}
 	mNumReserved = mIndex = mCurIndex = 0;
 }
 
 FFlatVertexBuffer::~FFlatVertexBuffer()
 {
-	if (gl.flags & RFL_BUFFER_STORAGE)
+	if (vbo_id != 0)
 	{
 		glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
 		glUnmapBuffer(GL_ARRAY_BUFFER);
 		glBindBuffer(GL_ARRAY_BUFFER, 0);
 	}
+	else
+	{
+		delete[] map;
+	}
+	map = nullptr;
 }
 
 
@@ -116,14 +121,15 @@ void FFlatVertexBuffer::BindVBO()
 		{
 			glVertexAttribPointer(VATTR_VERTEX, 3, GL_FLOAT, false, sizeof(FFlatVertex), &VTO->x);
 			glVertexAttribPointer(VATTR_TEXCOORD, 2, GL_FLOAT, false, sizeof(FFlatVertex), &VTO->u);
-			glEnableVertexAttribArray(VATTR_VERTEX);
-			glEnableVertexAttribArray(VATTR_TEXCOORD);
 		}
 		else
 		{
-			glDisableVertexAttribArray(VATTR_VERTEX);
-			glDisableVertexAttribArray(VATTR_TEXCOORD);
+			// If we cannot use a hardware buffer, use an old-style client array.
+			glVertexAttribPointer(VATTR_VERTEX, 3, GL_FLOAT, false, sizeof(FFlatVertex), &map->x);
+			glVertexAttribPointer(VATTR_TEXCOORD, 2, GL_FLOAT, false, sizeof(FFlatVertex), &map->u);
 		}
+		glEnableVertexAttribArray(VATTR_VERTEX);
+		glEnableVertexAttribArray(VATTR_TEXCOORD);
 		glDisableVertexAttribArray(VATTR_COLOR);
 		glDisableVertexAttribArray(VATTR_VERTEX2);
 	}
@@ -346,24 +352,10 @@ void FFlatVertexBuffer::UpdatePlaneVertices(sector_t *sec, int plane)
 
 void FFlatVertexBuffer::CreateVBO()
 {
-	if (gl.flags & RFL_BUFFER_STORAGE)
-	{
 	vbo_shadowdata.Resize(mNumReserved);
 	CreateFlatVBO();
 	mCurIndex = mIndex = vbo_shadowdata.Size();
 	memcpy(map, &vbo_shadowdata[0], vbo_shadowdata.Size() * sizeof(FFlatVertex));
-	}
-	else if (sectors)
-	{
-		// set all VBO info to invalid values so that we can save some checks in the rendering code
-		for(int i=0;i<numsectors;i++)
-		{
-			sectors[i].vboindex[3] = sectors[i].vboindex[2] = 
-			sectors[i].vboindex[1] = sectors[i].vboindex[0] = -1;
-			sectors[i].vboheight[1] = sectors[i].vboheight[0] = FLT_MIN;
-		}
-	}
-
 }
 
 //==========================================================================
@@ -395,12 +387,9 @@ void FFlatVertexBuffer::CheckPlanes(sector_t *sector)
 
 void FFlatVertexBuffer::CheckUpdate(sector_t *sector)
 {
-	if (gl.flags & RFL_BUFFER_STORAGE)
-	{
 	CheckPlanes(sector);
 	sector_t *hs = sector->GetHeightSec();
 	if (hs != NULL) CheckPlanes(hs);
 	for (unsigned i = 0; i < sector->e->XFloor.ffloors.Size(); i++)
 		CheckPlanes(sector->e->XFloor.ffloors[i]->model);
-	}
 }

src/gl/data/gl_vertexbuffer.h

@@ -85,14 +85,7 @@ public:
 	void RenderArray(unsigned int primtype, unsigned int offset, unsigned int count)
 	{
 		drawcalls.Clock();
-		if (gl.flags & RFL_BUFFER_STORAGE)
-		{
 		glDrawArrays(primtype, offset, count);
-		}
-		else
-		{
-			ImmRenderBuffer(primtype, offset, count);
-		}
 		drawcalls.Unclock();
 	}
 

src/gl/system/gl_interface.cpp

@@ -167,6 +167,7 @@ void gl_LoadExtensions()
 
 	gl.vendorstring = (char*)glGetString(GL_VENDOR);
 	gl.lightmethod = LM_SOFTWARE;
+	gl.buffermethod = BM_CLIENTARRAY;
 
 	if ((gl.version >= 3.3f || CheckExtension("GL_ARB_sampler_objects")) && !Args->CheckParm("-nosampler"))
 	{
@@ -177,6 +178,10 @@ void gl_LoadExtensions()
 	if (gl.version > 3.0f && (gl.version >= 3.3f || CheckExtension("GL_ARB_uniform_buffer_object")))
 	{
 		gl.lightmethod = LM_DEFERRED;
+		// Only Apple requires the core profile for GL 3.x+.
+		// #ifdef __APPLE__
+		// gl.buffermethod = BM_DEFERRED;
+		// #endif
 	}
 
 	if (CheckExtension("GL_ARB_texture_compression")) gl.flags |= RFL_TEXTURE_COMPRESSION;
@@ -222,6 +227,7 @@ void gl_LoadExtensions()
 			}
 			gl.flags |= RFL_BUFFER_STORAGE;
 			gl.lightmethod = LM_DIRECT;
+			gl.buffermethod = BM_PERSISTENT;
 		}
 		else
 		{
@@ -236,6 +242,13 @@ void gl_LoadExtensions()
 		if (!stricmp(lm, "textured")) gl.lightmethod = LM_SOFTWARE;
 	}
 
+	lm = Args->CheckValue("-buffermethod");
+	if (lm != NULL)
+	{
+		//if (!stricmp(lm, "deferred") && gl.buffermethod == BM_PERSISTENT) gl.buffermethod = BM_DEFERRED;
+		if (!stricmp(lm, "clientarray")) gl.buffermethod = BM_CLIENTARRAY;
+	}
+
 	int v;
 	
 	if (gl.lightmethod != LM_SOFTWARE && !(gl.flags & RFL_SHADER_STORAGE_BUFFER))

src/gl/system/gl_interface.h

@@ -44,6 +44,14 @@ enum ELightMethod
 	LM_DIRECT = 2,		// calculate lights on the fly along with the render data
 };
 
+enum EBufferMethod
+{
+	BM_CLIENTARRAY = 0,	// use a client array instead of a hardware buffer
+	BM_DEFERRED = 1,	// use a temporarily mapped buffer (only necessary on GL 3.x core profile, i.e. Apple)
+	BM_PERSISTENT = 2	// use a persistently mapped buffer
+};
+
+
 struct RenderContext
 {
 	unsigned int flags;
@@ -51,6 +59,7 @@ struct RenderContext
 	unsigned int maxuniformblock;
 	unsigned int uniformblockalignment;
 	int lightmethod;
+	int buffermethod;
 	float version;
 	float glslversion;
 	int max_texturesize;