diff --git a/examples/17-drawstress/drawstress.cpp b/examples/17-drawstress/drawstress.cpp
index ca3e23f0..429c4445 100644
--- a/examples/17-drawstress/drawstress.cpp
+++ b/examples/17-drawstress/drawstress.cpp
@@ -149,12 +149,13 @@ int _main_(int /*_argc*/, char** /*_argv*/)
 	{
 		int64_t now = bx::getHPCounter();
 		static int64_t last = now;
+		const int64_t hpFreq = bx::getHPFrequency();
 		const int64_t frameTime = now - last;
 		last = now;
-		const double freq = double(bx::getHPFrequency() );
+		const double freq = double(hpFreq);
 		const double toMs = 1000.0/freq;
 
-		deltaTimeNs += frameTime*1000000/bx::getHPFrequency();
+		deltaTimeNs += frameTime*1000000/hpFreq;
 
 		if (deltaTimeNs > 1000000)
 		{
@@ -172,8 +173,8 @@ int _main_(int /*_argc*/, char** /*_argv*/)
 				}
 			}
 
-			deltaTimeNs = deltaTimeAvgNs;
-			numFrames = 1;
+			deltaTimeNs = 0;
+			numFrames = 0;
 		}
 		else
 		{
diff --git a/src/glimports.h b/src/glimports.h
index 50665678..27afab36 100644
--- a/src/glimports.h
+++ b/src/glimports.h
@@ -45,9 +45,13 @@ typedef void           (GL_APIENTRYP PFNGLBINDTEXTUREPROC) (GLenum target, GLuin
 typedef void           (GL_APIENTRYP PFNGLBINDVERTEXARRAYPROC) (GLuint array);
 typedef void           (GL_APIENTRYP PFNGLBLENDCOLORPROC) (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
 typedef void           (GL_APIENTRYP PFNGLBLENDEQUATIONPROC) (GLenum mode);
+typedef void           (GL_APIENTRYP PFNGLBLENDEQUATIONIPROC) (GLuint buf, GLenum mode);
 typedef void           (GL_APIENTRYP PFNGLBLENDEQUATIONSEPARATEPROC) (GLenum modeRGB, GLenum modeAlpha);
+typedef void           (GL_APIENTRYP PFNGLBLENDEQUATIONSEPARATEIPROC) (GLuint buf, GLenum modeRGB, GLenum modeAlpha);
 typedef void           (GL_APIENTRYP PFNGLBLENDFUNCPROC) (GLenum sfactor, GLenum dfactor);
+typedef void           (GL_APIENTRYP PFNGLBLENDFUNCIPROC) (GLuint buf, GLenum src, GLenum dst);
 typedef void           (GL_APIENTRYP PFNGLBLENDFUNCSEPARATEPROC) (GLenum sfactorRGB, GLenum dfactorRGB, GLenum sfactorAlpha, GLenum dfactorAlpha);
+typedef void           (GL_APIENTRYP PFNGLBLENDFUNCSEPARATEIPROC) (GLuint buf, GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha);
 typedef void           (GL_APIENTRYP PFNGLBLITFRAMEBUFFERPROC) (GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter);
 typedef void           (GL_APIENTRYP PFNGLBUFFERDATAPROC) (GLenum target, GLsizeiptr size, const void *data, GLenum usage);
 typedef void           (GL_APIENTRYP PFNGLBUFFERSUBDATAPROC) (GLenum target, GLintptr offset, GLsizeiptr size, const void *data);
@@ -195,9 +199,13 @@ GL_IMPORT______(false, PFNGLBINDTEXTUREPROC,                       glBindTexture
 GL_IMPORT______(true,  PFNGLBINDVERTEXARRAYPROC,                   glBindVertexArray);
 GL_IMPORT______(true,  PFNGLBLENDCOLORPROC,                        glBlendColor);
 GL_IMPORT______(false, PFNGLBLENDEQUATIONPROC,                     glBlendEquation);
+GL_IMPORT______(true,  PFNGLBLENDEQUATIONIPROC,                    glBlendEquationi);
 GL_IMPORT______(true,  PFNGLBLENDEQUATIONSEPARATEPROC,             glBlendEquationSeparate);
+GL_IMPORT______(true,  PFNGLBLENDEQUATIONSEPARATEIPROC,            glBlendEquationSeparatei);
 GL_IMPORT______(false, PFNGLBLENDFUNCPROC,                         glBlendFunc);
+GL_IMPORT______(true,  PFNGLBLENDFUNCIPROC,                        glBlendFunci);
 GL_IMPORT______(true,  PFNGLBLENDFUNCSEPARATEPROC,                 glBlendFuncSeparate);
+GL_IMPORT______(true,  PFNGLBLENDFUNCSEPARATEIPROC,                glBlendFuncSeparatei);
 GL_IMPORT______(true,  PFNGLBLITFRAMEBUFFERPROC,                   glBlitFramebuffer);
 GL_IMPORT______(false, PFNGLBUFFERDATAPROC,                        glBufferData);
 GL_IMPORT______(false, PFNGLBUFFERSUBDATAPROC,                     glBufferSubData);
@@ -336,6 +344,11 @@ GL_IMPORT_ARB__(true,  PFNGLOBJECTPTRLABELPROC,                    glObjectPtrLa
 GL_IMPORT_ARB__(true,  PFNGLGETOBJECTPTRLABELPROC,                 glGetObjectPtrLabel);
 GL_IMPORT_ARB__(true,  PFNGLGETPOINTERVPROC,                       glGetPointerv);
 
+GL_IMPORT_ARB__(true,  PFNGLBLENDEQUATIONIPROC,                    glBlendEquationi);
+GL_IMPORT_ARB__(true,  PFNGLBLENDEQUATIONSEPARATEIPROC,            glBlendEquationSeparatei);
+GL_IMPORT_ARB__(true,  PFNGLBLENDFUNCIPROC,                        glBlendFunci);
+GL_IMPORT_ARB__(true,  PFNGLBLENDFUNCSEPARATEIPROC,                glBlendFuncSeparatei);
+
 GL_IMPORT_ARB__(true,  PFNGLVERTEXATTRIBDIVISORPROC,               glVertexAttribDivisor);
 GL_IMPORT_ARB__(true,  PFNGLDRAWARRAYSINSTANCEDPROC,               glDrawArraysInstanced);
 GL_IMPORT_ARB__(true,  PFNGLDRAWELEMENTSINSTANCEDPROC,             glDrawElementsInstanced);
diff --git a/src/renderer_gl.cpp b/src/renderer_gl.cpp
index e40076df..958d8792 100644
--- a/src/renderer_gl.cpp
+++ b/src/renderer_gl.cpp
@@ -216,6 +216,7 @@ namespace bgfx
 			ARB_debug_label,
 			ARB_debug_output,
 			ARB_depth_clamp,
+			ARB_draw_buffers_blend,
 			ARB_ES3_compatibility,
 			ARB_framebuffer_object,
 			ARB_framebuffer_sRGB,
@@ -335,6 +336,7 @@ namespace bgfx
 		{ "GL_ARB_debug_label",                    false,                             true  },
 		{ "GL_ARB_debug_output",                   BGFX_CONFIG_RENDERER_OPENGL >= 43, true  },
 		{ "GL_ARB_depth_clamp",                    BGFX_CONFIG_RENDERER_OPENGL >= 32, true  },
+		{ "GL_ARB_draw_buffers_blend",             BGFX_CONFIG_RENDERER_OPENGL >= 40, true  },
 		{ "GL_ARB_ES3_compatibility",              BGFX_CONFIG_RENDERER_OPENGL >= 43, true  },
 		{ "GL_ARB_framebuffer_object",             BGFX_CONFIG_RENDERER_OPENGL >= 30, true  },
 		{ "GL_ARB_framebuffer_sRGB",               BGFX_CONFIG_RENDERER_OPENGL >= 30, true  },
@@ -512,7 +514,7 @@ namespace bgfx
 		//
 		// If <length> is 0 then <marker> is assumed to be null-terminated.
 
-		uint32_t size = (0 == _length ? strlen(_marker) : _length) + 1;
+		uint32_t size = (0 == _length ? (uint32_t)strlen(_marker) : _length) + 1;
 		size *= sizeof(wchar_t);
 		wchar_t* name = (wchar_t*)alloca(size);
 		mbstowcs(name, _marker, size-2);
@@ -1859,6 +1861,7 @@ namespace bgfx
 		else
 		{
 			BX_UNUSED(_zoffset, _depth);
+			BX_TRACE("x %d, y %d, w %d, h %d", _xoffset, _yoffset, _width, _height);
 			GL_CHECK(glTexSubImage2D(_target, _level, _xoffset, _yoffset, _width, _height, _format, _type, _data) );
 		}
 	}