Adding generic immediate mode drawing API and migrating microprofile.

Future changes will move elemental-forms and imgui to the common API as
well.

src/xenia/ui/microprofile_drawer.h

@@ -0,0 +1,65 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2015 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_MICROPROFILE_DRAWER_H_
+#define XENIA_UI_MICROPROFILE_DRAWER_H_
+
+#include <memory>
+#include <vector>
+
+#include "xenia/ui/immediate_drawer.h"
+
+namespace xe {
+namespace ui {
+
+class GraphicsContext;
+class Window;
+
+class MicroprofileDrawer {
+ public:
+  enum class BoxType {
+    kBar = 0,   // MicroProfileBoxTypeBar
+    kFlat = 1,  // MicroProfileBoxTypeFlat
+  };
+
+  MicroprofileDrawer(Window* window);
+  ~MicroprofileDrawer();
+
+  void Begin();
+  void End();
+  void DrawBox(int x0, int y0, int x1, int y1, uint32_t color, BoxType type);
+  void DrawLine2D(uint32_t count, float* vertices, uint32_t color);
+  void DrawText(int x, int y, uint32_t color, const char* text,
+                int text_length);
+
+ protected:
+  void SetupFont();
+
+  ImmediateVertex* BeginVertices(ImmediatePrimitiveType primitive_type,
+                                 int count);
+  void EndVertices();
+  void Flush();
+
+  Window* window_ = nullptr;
+  GraphicsContext* graphics_context_ = nullptr;
+
+  std::vector<ImmediateVertex> vertices_;
+  int vertex_count_ = 0;
+  ImmediatePrimitiveType current_primitive_type_;
+
+  std::unique_ptr<ImmediateTexture> font_texture_;
+  struct {
+    uint16_t char_offsets[256];
+  } font_description_ = {{0}};
+};
+
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_MICROPROFILE_DRAWER_H_