Add PushBuffer

Adds `PushBuffer` class, `pushBuffer` global, and the supporting code for `glconfig2`.

Author: VReaperV

src/engine/renderer/BufferBind.h

@@ -42,9 +42,10 @@ namespace BufferBind {
 		MATERIALS = 0,
 		TEX_DATA = 1,
 		LIGHTMAP_DATA = 2,
-		LIGHTS = 3,
+		GLOBAL_DATA = 3,
+		LIGHTS = 4,
 
-		SURFACE_BATCHES = 4,
+		SURFACE_BATCHES = 5,
 
 		// SSBO
 		SURFACE_DESCRIPTORS = 0,

src/engine/renderer/GLMemory.cpp

@@ -37,10 +37,13 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "GLMemory.h"
 
+#include "gl_shader.h"
+
 // 128 MB, should be enough to fit anything in BAR without going overboard
 const GLsizeiptr GLStagingBuffer::SIZE = 128 * 1024 * 1024 / sizeof( uint32_t );
 
 GLStagingBuffer stagingBuffer;
+PushBuffer pushBuffer;
 
 void GLBufferCopy( GLBuffer* src, GLBuffer* dst, GLintptr srcOffset, GLintptr dstOffset, GLsizeiptr size ) {
 	glCopyNamedBufferSubData( src->id, dst->id,
@@ -130,3 +133,32 @@ void GLStagingBuffer::FreeGLBuffer() {
 	current = 0;
 	last = 0;
 }
+
+void PushBuffer::InitGLBuffers() {
+	globalUBO.GenBuffer();
+}
+
+void PushBuffer::FreeGLBuffers() {
+	globalUBO.DelBuffer();
+}
+
+uint32_t* PushBuffer::MapGlobalUniformData( const int updateType ) {
+	switch ( updateType ) {
+		case GLUniform::CONST:
+			globalUBOData = stagingBuffer.MapBuffer( constUniformsSize );
+			stagingBuffer.QueueStagingCopy( &globalUBO, 0 );
+			break;
+		case GLUniform::FRAME:
+			globalUBOData = stagingBuffer.MapBuffer( frameUniformsSize );
+			stagingBuffer.QueueStagingCopy( &globalUBO, constUniformsSize );
+			break;
+		default:
+			ASSERT_UNREACHABLE();
+	}
+
+	return globalUBOData;
+}
+
+void PushBuffer::PushGlobalUniforms() {
+	stagingBuffer.FlushAll();
+}

src/engine/renderer/GLMemory.h

@@ -38,6 +38,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "common/Common.h"
 #include "GL/glew.h"
+
 #include "tr_local.h"
 #include "BufferBind.h"
 
@@ -318,6 +319,28 @@ class GLStagingBuffer {
 		GL_MAP_FLUSH_EXPLICIT_BIT | GL_MAP_INVALIDATE_BUFFER_BIT );
 };
 
+struct PushBuffer {
+	uint32_t constUniformsSize;
+	uint32_t frameUniformsSize;
+	uint32_t globalUBOSize;
+	uint32_t* globalUBOData;
+
+	uint32_t pushStart = UINT32_MAX;
+	uint32_t pushEnd = 0;
+
+	uint32_t sector = 0;
+	const uint32_t MAX_SECTORS = 1024;
+
+	GLUBO globalUBO = GLUBO( "globalUniforms", BufferBind::GLOBAL_DATA, 0, 0 );
+
+	void InitGLBuffers();
+	void FreeGLBuffers();
+
+	uint32_t* MapGlobalUniformData( const int updateType );
+	void PushGlobalUniforms();
+};
+
 extern GLStagingBuffer stagingBuffer;
+extern PushBuffer pushBuffer;
 
-#endif // GLMEMORY_H
+#endif // GLMEMORY_H

src/engine/renderer/tr_public.h

@@ -120,6 +120,7 @@ struct glconfig2_t
 	bool usingMaterialSystem; // are we using it right now
 	bool geometryCacheAvailable;
 	bool usingGeometryCache;
+	bool pushBufferAvailable;
 	bool gpuShader4Available;
 	bool gpuShader5Available;
 	bool textureGatherAvailable;

src/engine/sys/sdl_glimp.cpp

@@ -2591,6 +2591,11 @@ static void GLimp_InitExtensions()
 
 	glConfig2.geometryCacheAvailable = glConfig2.vertexAttribBindingAvailable && glConfig2.directStateAccessAvailable;
 
+	glConfig2.pushBufferAvailable =
+		glConfig2.directStateAccessAvailable
+		&& glConfig2.explicitUniformLocationAvailable
+		&& glConfig2.uniformBufferObjectAvailable;
+
 	glConfig2.materialSystemAvailable =
 		glConfig2.bindlessTexturesAvailable
 		&& glConfig2.computeShaderAvailable