OGL: implement bounding box support with ssbo

This implemention tries to be as accurate as the old SW implemention, but it will remove the dependcy of our vertexloader on videosw.

1 files changed, 54 insertions, 0 deletions

diff --git a/Source/Core/VideoBackends/OGL/BoundingBox.cpp b/Source/Core/VideoBackends/OGL/BoundingBox.cpp
new file mode 100644
index 0000000000..91fedb2a2d
--- /dev/null
+++ b/Source/Core/VideoBackends/OGL/BoundingBox.cpp
@@ -0,0 +1,54 @@
+// Copyright 2014 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "VideoBackends/OGL/BoundingBox.h"
+#include "VideoBackends/OGL/GLUtil.h"
+
+#include "VideoCommon/VideoConfig.h"
+
+static GLuint s_bbox_buffer_id;
+
+namespace OGL
+{
+
+void BoundingBox::Init()
+{
+	if (g_ActiveConfig.backend_info.bSupportsBBox)
+	{
+		int initial_values[4] = {0,0,0,0};
+		glGenBuffers(1, &s_bbox_buffer_id);
+		glBindBuffer(GL_SHADER_STORAGE_BUFFER, s_bbox_buffer_id);
+		glBufferData(GL_SHADER_STORAGE_BUFFER, 4 * sizeof(s32), initial_values, GL_DYNAMIC_DRAW);
+		glBindBufferBase(GL_SHADER_STORAGE_BUFFER, 3, s_bbox_buffer_id);
+	}
+}
+
+void BoundingBox::Shutdown()
+{
+	if (g_ActiveConfig.backend_info.bSupportsBBox)
+		glDeleteBuffers(1, &s_bbox_buffer_id);
+}
+
+void BoundingBox::Set(int index, int value)
+{
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, s_bbox_buffer_id);
+	glBufferSubData(GL_SHADER_STORAGE_BUFFER, index * sizeof(int), sizeof(int), &value);
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
+}
+
+int BoundingBox::Get(int index)
+{
+	int data = 0;
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, s_bbox_buffer_id);
+	void* ptr = glMapBufferRange(GL_SHADER_STORAGE_BUFFER, index * sizeof(int), sizeof(int), GL_MAP_READ_BIT);
+	if (ptr)
+	{
+		data = *(int*)ptr;
+		glUnmapBuffer(GL_SHADER_STORAGE_BUFFER);
+	}
+	glBindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
+	return data;
+}
+
+};