Fix gl.ClearAttachmentFBO() doc and expose Platform.glVersionNum to Lua

Author: lhog

rts/Lua/LuaConstPlatform.cpp

@@ -49,6 +49,7 @@ bool LuaConstPlatform::PushEntries(lua_State* L)
 	LuaPushNamedString(L, "gpuVendor", globalRenderingInfo.gpuVendor);
 	LuaPushNamedNumber(L, "gpuMemorySize", globalRenderingInfo.gpuMemorySize.x);
 	LuaPushNamedString(L, "glVersionShort", globalRenderingInfo.glVersionShort.data());
+	LuaPushNamedNumber(L, "glVersionNum", globalRenderingInfo.glVersionNum);
 	LuaPushNamedString(L, "glslVersionShort", globalRenderingInfo.glslVersionShort.data());
 	LuaPushNamedNumber(L, "glslVersionNum", globalRenderingInfo.glslVersionNum);
 

rts/Lua/LuaFBOs.cpp

@@ -784,7 +784,7 @@ namespace Impl {
 	}
 }
 
-/*** needs `Platform.glslVersionNum >= 300`
+/*** needs `Platform.glVersionNum >= 30`
  * Clears the "attachment" of the currently bound FBO type "target" with "clearValues"
  * 
  * @function gl.ClearAttachmentFBO

rts/Rendering/GlobalRendering.cpp

@@ -824,6 +824,9 @@ void CGlobalRendering::SetGLSupportFlags()
 			break;
 		}
 	}
+	if (int2 glVerNum = { 0, 0 }; sscanf(globalRenderingInfo.glVersionShort.data(), "%d.%d", &glVerNum.x, &glVerNum.y) == 2) {
+		globalRenderingInfo.glslVersionNum = glVerNum.x * 10 + glVerNum.y;
+	}
 
 	for (size_t n = 0; (n < sizeof(globalRenderingInfo.glslVersionShort) && globalRenderingInfo.glslVersion[n] != 0); n++) {
 		if ((globalRenderingInfo.glslVersionShort[n] = globalRenderingInfo.glslVersion[n]) == ' ') {

rts/Rendering/GlobalRenderingInfo.h

@@ -32,6 +32,7 @@ struct GlobalRenderingInfo {
 	std::array<char, 256> glVersionShort = { 0 };
 	std::array<char, 256> glslVersionShort = { 0 };
 
+	int glVersionNum = 0;
 	int glslVersionNum = 0;
 
 	bool glContextIsCore;