renderer_gl: Implement stencil testing

include/PICA/regs.hpp

@@ -55,6 +55,8 @@ namespace PICA {
 			BlendFunc = 0x101,
 			BlendColour = 0x103,
 			AlphaTestConfig = 0x104,
+			StencilTest = 0x105,
+			StencilOp = 0x106,
 			DepthAndColorMask = 0x107,
 			DepthBufferFormat = 0x116,
 			ColourBufferFormat = 0x117,

include/renderer_gl/renderer_gl.hpp

@@ -61,6 +61,7 @@ class RendererGL final : public Renderer {
 
 	MAKE_LOG_FUNCTION(log, rendererLogger)
 	void setupBlending();
+	void setupStencilTest(bool stencilEnable);
 	void bindDepthBuffer();
 	void setupTextureEnvState();
 	void bindTexturesToSlots();
@@ -79,4 +80,4 @@ class RendererGL final : public Renderer {
 
 	// Take a screenshot of the screen and store it in a file
 	void screenshot(const std::string& name) override;
-};
+};