From 973bf5abdfe821b33963b712d00c92f3742cdf23 Mon Sep 17 00:00:00 2001
From: kd-11 <karokidii@gmail.com>
Date: Thu, 20 Oct 2016 06:20:45 +0300
Subject: [PATCH] gl: Disable overlay if required extension is not supported
 (#2212)

---
 rpcs3/Emu/RSX/GL/GLGSRender.cpp |  4 +++-
 rpcs3/Emu/RSX/GL/GLProcTable.h  |  1 +
 rpcs3/Emu/RSX/GL/GLTextOut.h    | 25 +++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/rpcs3/Emu/RSX/GL/GLGSRender.cpp b/rpcs3/Emu/RSX/GL/GLGSRender.cpp
index e3f181e8a4..d3c2d2b82b 100644
--- a/rpcs3/Emu/RSX/GL/GLGSRender.cpp
+++ b/rpcs3/Emu/RSX/GL/GLGSRender.cpp
@@ -559,7 +559,9 @@ void GLGSRender::on_init_thread()
 
 	m_vao.element_array_buffer = *m_index_ring_buffer;
 	m_gl_texture_cache.initialize_rtt_cache();
-	m_text_printer.init();
+
+	if (g_cfg_rsx_overlay)
+		m_text_printer.init();
 }
 
 void GLGSRender::on_exit()
diff --git a/rpcs3/Emu/RSX/GL/GLProcTable.h b/rpcs3/Emu/RSX/GL/GLProcTable.h
index 0e3ce9a83f..403ed392d8 100644
--- a/rpcs3/Emu/RSX/GL/GLProcTable.h
+++ b/rpcs3/Emu/RSX/GL/GLProcTable.h
@@ -160,6 +160,7 @@ OPENGL_PROC(PFNGLDISABLEIPROC, Disablei);
 OPENGL_PROC(PFNGLPRIMITIVERESTARTINDEXPROC, PrimitiveRestartIndex);
 
 OPENGL_PROC(PFNGLGETINTEGER64VPROC, GetInteger64v);
+OPENGL_PROC(PFNGLGETSTRINGIPROC, GetStringi);
 
 OPENGL_PROC(PFNGLCHECKFRAMEBUFFERSTATUSPROC, CheckFramebufferStatus);
 
diff --git a/rpcs3/Emu/RSX/GL/GLTextOut.h b/rpcs3/Emu/RSX/GL/GLTextOut.h
index 237a44e6aa..ebdc1ec241 100644
--- a/rpcs3/Emu/RSX/GL/GLTextOut.h
+++ b/rpcs3/Emu/RSX/GL/GLTextOut.h
@@ -20,6 +20,7 @@ namespace gl
 		std::unordered_map<u8, std::pair<u32, u32>> m_offsets;
 
 		bool initialized = false;
+		bool enabled = false;
 
 		void init_program()
 		{
@@ -84,6 +85,28 @@ namespace gl
 
 		void init()
 		{
+			//Check for ARB_shader_draw_parameters
+			//While it is possible to draw text without full multidraw support, issuing separate draw calls per character is not effecient
+
+			int ext_count;
+			glGetIntegerv(GL_NUM_EXTENSIONS, &ext_count);
+			
+			for (int i = 0; i < ext_count; i++)
+			{
+				const char *ext = (const char*)glGetStringi(GL_EXTENSIONS, i);
+				if (std::string(ext) == "GL_ARB_shader_draw_parameters")
+				{
+					enabled = true;
+					break;
+				}
+			}
+
+			if (!enabled)
+			{
+				LOG_ERROR(RSX, "Debug overlay could not start because ARB_shader_draw_parameters is not supported by your GPU");
+				return;
+			}
+
 			m_text_buffer.create();
 			m_scale_offsets_buffer.create();
 
@@ -117,6 +140,8 @@ namespace gl
 
 		void print_text(int x, int y, int target_w, int target_h, const std::string &text, color4f color = { 0.3f, 1.f, 0.3f, 1.f })
 		{
+			if (!enabled) return;
+
 			verify(HERE), initialized;
 
 			std::vector<GLint> offsets;