Add backends

- Renamed GfxOpenGL to GfxOPenGL2
- Added GfxOpenGL3 backend for OpenGL 3.3+
- Added WIP DirectX9 backend
- Added structure for Citro3D
- Added linear Allocator

backends/source/gfx_citro3d.cpp

@@ -0,0 +1,69 @@
+// Well yes, i finally try it
+
+#include <pd_system/gfx_citro3d.hpp>
+
+#if defined(PD_ENABLE_CITRO3D)  // && defined(__3DS__)
+
+#include <3ds.h>
+#include <citro3d.h>
+
+#include <pd/drivers/drivers.hpp>
+
+namespace PD {
+struct GfxCitro3D::Impl {};
+
+void GfxCitro3D::SysInit() {
+  if (impl) return;
+  PDLOG("GfxCitro3D::SysInit();");
+  impl = new Impl();
+}
+
+void GfxCitro3D::SysDeinit() {
+  if (!impl) return;
+  delete impl;
+  impl = nullptr;
+  PDLOG("GfxCitro3D::SysDeinit()");
+}
+
+void GfxCitro3D::Submit(size_t count, size_t start) {
+  if (!impl) return;
+}
+
+void GfxCitro3D::BindTexture(TextureID id) {
+  if (!impl) return;
+}
+
+void GfxCitro3D::SysReset() {
+  if (!impl) return;
+}
+
+TextureID GfxCitro3D::LoadTexture(const std::vector<PD::u8>& pixels, int w,
+                                  int h, TextureFormat type,
+                                  TextureFilter filter) {
+  if (!impl) return 0;
+  return 0;
+}
+
+void GfxCitro3D::DeleteTexture(const TextureID& tex) {
+  if (!tex) return;
+}
+}  // namespace PD
+#else
+namespace PD {
+void GfxCitro3D::SysInit() {
+  PDLOG(
+      "GfxCitro3D::SysInit: Citro3D Driver is not included in "
+      "palladium-system");
+}
+void GfxCitro3D::SysDeinit() {}
+void GfxCitro3D::Submit(size_t count, size_t start) {}
+void GfxCitro3D::BindTexture(TextureID id) {}
+void GfxCitro3D::SysReset() {}
+TextureID GfxCitro3D::LoadTexture(const std::vector<PD::u8>& pixels, int w,
+                                  int h, TextureFormat type,
+                                  TextureFilter filter) {
+  return 0;
+}
+void GfxCitro3D::DeleteTexture(const TextureID& tex) {}
+}  // namespace PD
+#endif