GL::State & Texture bind cosmetic (#927)

* Texture binding cosmetic

Eliminate "duplicate" of FormatToQuery (Format2Query), move FormatToQuery -> TextureFormat.h and make it extern (only 1 instance among all units).
Gate unaccepted texture targets for Lua via switch.


* GL::State

State is implemented as a namespace.
Use it like this:
using namespace GL::State;

auto stateChange = StateChange(DepthMask(GL_TRUE), Viewport(0,0,1,1));
...
stateChange.pop()

or
{
    auto stateChange = StateChange(...);
    ...
    // stateChange destructed
}

Unknown status is implemented via union. It should be safe, no practical value should collide with it.

* Update GL::State

Enabled "capability" ("binary") attributes

Corrected previous union usage, it now uses a pair (not optional, because it works with values when false)

Todo: BindTexture, ClipDistance

* Update, should be ready

StateChange > PushState

PushState should be ready, but is not test yet. Shall be testing.

+ClipDistance attribute. Note, it doesn't check how many clip distances are available, it just runs gl function as it should. Check clip distances, if you need, prior to ClipDistance code.

Replace glPushAttrib with PushState in some places where its easy

* >SubState + operator <<

PushState > SubState

Add operator << to modify state

rts/Game/UI/MiniMap.cpp

@@ -35,6 +35,7 @@
 #include "Rendering/GL/myGL.h"
 #include "Rendering/GL/glExtra.h"
 #include "Rendering/GL/RenderBuffers.h"
+#include "Rendering/GL/SubState.h"
 #include "Rendering/Textures/Bitmap.h"
 #include "Sim/Units/CommandAI/CommandAI.h"
 #include "Sim/Units/Unit.h"
@@ -50,6 +51,9 @@
 #include "System/FileSystem/SimpleParser.h"
 #include "System/Sound/ISoundChannels.h"
 
+using namespace GL::State;
+
+
 CONFIG(std::string, MiniMapGeometry).defaultValue("2 2 200 200");
 CONFIG(bool, MiniMapFullProxy).defaultValue(true);
 CONFIG(int, MiniMapButtonSize).defaultValue(16);
@@ -1128,17 +1132,18 @@ void CMiniMap::Draw()
 	{
 		glEnable(GL_BLEND);
 		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-		glPushAttrib(GL_DEPTH_BUFFER_BIT);
-		glDisable(GL_DEPTH_TEST);
-		glDepthFunc(GL_LEQUAL);
-		glDepthMask(GL_FALSE);
+
+		auto state = GL::SubState(
+			DepthTest(GL_FALSE),
+			DepthFunc(GL_LEQUAL),
+			DepthMask(GL_FALSE));
+
 		glDisable(GL_TEXTURE_2D);
 		glMatrixMode(GL_MODELVIEW);
 
 		if (minimized) {
 			DrawMinimizedButtonQuad();
 			DrawMinimizedButtonLoop();
-			glPopAttrib();
 			glEnable(GL_TEXTURE_2D);
 			return;
 		}
@@ -1148,8 +1153,6 @@ void CMiniMap::Draw()
 			DrawFrame();
 			DrawButtons();
 		}
-
-		glPopAttrib();
 	}
 
 	// draw minimap itself

rts/Game/UI/MouseHandler.cpp

@@ -25,6 +25,7 @@
 #include "Rendering/Fonts/glFont.h"
 #include "Rendering/GL/myGL.h"
 #include "Rendering/GL/RenderBuffers.h"
+#include "Rendering/GL/SubState.h"
 #include "Rendering/Textures/Bitmap.h"
 #include "Sim/Features/Feature.h"
 #include "Sim/Units/Unit.h"
@@ -46,6 +47,8 @@
 #include <SDL_events.h>
 #include <SDL_keycode.h>
 
+using namespace GL::State;
+
 
 CONFIG(bool, HardwareCursor).defaultValue(false).description("Sets hardware mouse cursor rendering. If you have a low framerate, your mouse cursor will seem \"laggy\". Setting hardware cursor will render the mouse cursor separately from spring and the mouse will behave normally. Note, not all GPU drivers support it in fullscreen mode!");
 CONFIG(bool, InvertMouse).defaultValue(false);
@@ -572,20 +575,17 @@ void CMouseHandler::DrawSelectionBox() const
 		{tpLeft , cmdColors.mouseBox},
 	});
 
-	glPushAttrib(GL_ENABLE_BIT);
-	glDisable(GL_DEPTH_TEST);
-	glEnable(GL_BLEND);
-	glBlendFunc((GLenum)cmdColors.MouseBoxBlendSrc(), (GLenum)cmdColors.MouseBoxBlendDst());
+	auto state = GL::SubState(
+		DepthTest(GL_FALSE),
+		Blending(GL_TRUE),
+		BlendFunc((GLenum)cmdColors.MouseBoxBlendSrc(), (GLenum)cmdColors.MouseBoxBlendDst()),
+		LineWidth(cmdColors.MouseBoxLineWidth()));
 
-	glLineWidth(cmdColors.MouseBoxLineWidth());
 	sh.Enable();
 
 	rb.DrawArrays(GL_LINE_LOOP);
 
 	sh.Disable();
-	glLineWidth(1.0f);
-
-	glPopAttrib();
 }
 
 int2 CMouseHandler::GetViewMouseCenter() const

rts/Lua/LuaOpenGL.cpp

@@ -56,6 +56,7 @@
 #include "Rendering/Env/WaterRendering.h"
 #include "Rendering/Env/MapRendering.h"
 #include "Rendering/GL/glExtra.h"
+#include "Rendering/GL/TexBind.h"
 #include "Rendering/Models/3DModel.h"
 #include "Rendering/Shaders/Shader.h"
 #include "Rendering/Textures/Bitmap.h"
@@ -3627,12 +3628,8 @@ int LuaOpenGL::GenerateMipmap(lua_State* L)
 	if (tex == nullptr)
 		return 0;
 
-	GLint currentBinding;
-	assert(LuaTextures::Format2Query.find(tex->target) != LuaTextures::Format2Query.end());
-	glGetIntegerv(LuaTextures::Format2Query.find(tex->target)->second, &currentBinding);
-	glBindTexture(tex->target, tex->id);
+	auto texBind = GL::TexBind(tex->target, tex->id);
 	glGenerateMipmapEXT(tex->target);
-	glBindTexture(tex->target, currentBinding);
 
 	return 0;
 }

rts/Lua/LuaTextures.cpp

@@ -4,6 +4,7 @@
 #include "Rendering/Textures/TextureFormat.h"
 #include "Rendering/GlobalRendering.h"
 #include "Rendering/GL/FBO.h"
+#include "Rendering/GL/TexBind.h"
 #include "System/SpringMath.h"
 #include "System/StringUtil.h"
 #include "System/Log/ILog.h"
@@ -13,33 +14,42 @@
 #include "fmt/format.h"
 
 
-const spring::unordered_map<GLenum, GLenum> LuaTextures::Format2Query =
-{
-	{ GL_TEXTURE_1D                  , GL_TEXTURE_BINDING_1D				   },
-	{ GL_TEXTURE_2D                  , GL_TEXTURE_BINDING_2D				   },
-	{ GL_TEXTURE_3D                  , GL_TEXTURE_BINDING_3D				   },
-//	{ GL_TEXTURE_1D_ARRAY            , GL_TEXTURE_BINDING_1D_ARRAY			   },
-	{ GL_TEXTURE_2D_ARRAY            , GL_TEXTURE_BINDING_2D_ARRAY			   },
-//	{ GL_TEXTURE_RECTANGLE           , GL_TEXTURE_BINDING_RECTANGLE			   },
-	{ GL_TEXTURE_CUBE_MAP            , GL_TEXTURE_BINDING_CUBE_MAP			   },
-//	{ GL_TEXTURE_BUFFER              , GL_TEXTURE_BINDING_BUFFER			   },
-	{ GL_TEXTURE_2D_MULTISAMPLE      , GL_TEXTURE_BINDING_2D_MULTISAMPLE	   },
-//	{ GL_TEXTURE_2D_MULTISAMPLE_ARRAY, GL_TEXTURE_BINDING_2D_MULTISAMPLE_ARRAY },
-};
+namespace Impl {
+	static inline bool IsValidLuaTextureTarget(GLenum target) {
+		switch(target) {
+			case GL_TEXTURE_1D:
+			case GL_TEXTURE_2D:
+			case GL_TEXTURE_3D:
+			//case GL_TEXTURE_1D_ARRAY:
+			case GL_TEXTURE_2D_ARRAY:
+			//case GL_TEXTURE_RECTANGLE:
+			case GL_TEXTURE_CUBE_MAP:
+			//case GL_TEXTURE_BUFFER:
+			case GL_TEXTURE_2D_MULTISAMPLE:
+			//case GL_TEXTURE_2D_MULTISAMPLE_ARRAY:
+				return true;
+			default: break;
+		}
+		return false;
+	}
+}
 
 /******************************************************************************/
 /******************************************************************************/
 
 std::string LuaTextures::Create(const Texture& tex)
 {
-	GLint currentBinding = 0;
-
-	if (Format2Query.find(tex.target) == Format2Query.end()) {
+	GLenum query = 0;
+	if (Impl::IsValidLuaTextureTarget(tex.target)) {
+		query = GL::GetBindingQueryFromTarget(tex.target);
+	}
+	if (!query) {
 		LOG_L(L_ERROR, "[LuaTextures::%s] texture-target %d is not supported", __func__, tex.target);
 		return "";
 	}
 
-	glGetIntegerv(Format2Query.find(tex.target)->second, &currentBinding);
+	GLint currentBinding;
+	glGetIntegerv(query, &currentBinding);
 
 	GLuint texID;
 	glGenTextures(1, &texID);
@@ -254,11 +264,8 @@ void LuaTextures::ApplyParams(const Texture& tex) const
 
 void LuaTextures::ChangeParams(const Texture& tex)  const
 {
-	GLint currentBinding = 0;
-	glGetIntegerv(GL_TEXTURE_BINDING_2D, &currentBinding);
-	glBindTexture(tex.target, tex.id);
+	auto texBind = GL::TexBind(tex.target, tex.id);
 	ApplyParams(tex);
-	glBindTexture(GL_TEXTURE_2D, currentBinding); // revert the current binding
 }
 
 

rts/Lua/LuaTextures.h

@@ -7,7 +7,6 @@
 #include <vector>
 
 #include "Rendering/GL/myGL.h"
-#include "System/UnorderedMap.hpp"
 
 
 class LuaTextures {
@@ -73,8 +72,6 @@ class LuaTextures {
 
 	const Texture* GetInfo(const std::string& name) const { return (GetInfo(GetIdx(name))); }
 	      Texture* GetInfo(const std::string& name)       { return (GetInfo(GetIdx(name))); }
-public:
-	static const spring::unordered_map<GLenum, GLenum> Format2Query;
 private:
 	int lastCode;
 

rts/Rendering/CMakeLists.txt

@@ -63,6 +63,7 @@ set(sources_engine_Rendering
 		"${CMAKE_CURRENT_SOURCE_DIR}/GL/VBO.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/GL/VAO.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/GL/glExtra.cpp"
+		"${CMAKE_CURRENT_SOURCE_DIR}/GL/State.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/GL/myGL.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/VK/VkInit.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/VK/VkInfo.cpp"
@@ -115,6 +116,7 @@ set(sources_engine_Rendering
 		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/NamedTextures.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/S3OTextureHandler.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/TAPalette.cpp"
+		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/TextureFormat.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/TextureAtlas.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/TexturesSet.cpp"
 		"${CMAKE_CURRENT_SOURCE_DIR}/Textures/nv_dds.cpp"

rts/Rendering/GL/State.cpp

@@ -0,0 +1,3 @@
+#include "State.h"
+
+decltype(GL::State::Attributes) GL::State::Attributes;