Isometric Mode and Robin (#2618)

* Feature-complete isometric mode fork.

* Dithered transparency condition tweaks.

* Dithered transparency for non-corpse monsters only (and missiles).

* SpectatorCamera vertical shift.

* Including math.h in hw_sprites.cpp to keep visual studio happy (it couldn't find M_SQRT2 definition).

* Defining MY_SQRT2 in hw_sprites.cpp to keep visual studio happy (it couldn't find M_SQRT2 definition).

* Defining MY_SQRT2 in r_utility.cpp also to keep visual studio happy.

* retrigger checks

* Have correct sprite angle-frame face the camera with orthographic projection enabled.

* Dithered Transparency now works properly on 3D floors. Moved that dither-trans flag setting code within hw_bsp.cpp to handle double-processing of linedefs. Added helper functions to FRenderViewpoint class 'bool IsOrtho()' and 'bool IsAllowedOoB()' to clean up checks everywhere in the code.

* Fixed indents. Added bbox property to subsector struct and use it instead of BSP nodes and Clippers (creating a bbox around viewpoint and checking for overlap) in orthographic mode when no fog of war is active. Turns out to be much faster. Though you need really big maps (Winter's Fury MAP01) to see a difference in fps.

* Non-linux checks don't like uint. Changed to unsigned int.

* Small change of a float to camera.zs. Ignore for testing. Should make no difference.

* Update actor.h to remain mergeable

RF2_NOMIPMAP was introduced, so I had to displace RF_ISOMETRICSPRITES to next bit.

src/common/rendering/hwrenderer/data/hw_cvars.h

@@ -54,3 +54,6 @@ EXTERN_CVAR(Int, gl_shadowmap_filter)
 EXTERN_CVAR(Bool, gl_brightfog)
 EXTERN_CVAR(Bool, gl_lightadditivesurfaces)
 EXTERN_CVAR(Bool, gl_notexturefill)
+
+EXTERN_CVAR(Bool, r_radarclipper)
+EXTERN_CVAR(Bool, r_dithertransparency)

src/common/rendering/hwrenderer/data/hw_renderstate.h

@@ -25,7 +25,7 @@ enum ERenderEffect
 	EFF_SPHEREMAP,
 	EFF_BURN,
 	EFF_STENCIL,
-
+	EFF_DITHERTRANS,
 	MAX_EFFECTS
 };
 

src/common/rendering/hwrenderer/data/hw_shaderpatcher.cpp

@@ -299,6 +299,7 @@ const FEffectShader effectshaders[] =
 	{ "spheremap", "shaders/glsl/main.vp", "shaders/glsl/main.fp", "shaders/glsl/func_normal.fp", "shaders/glsl/material_normal.fp", "#define SPHEREMAP\n#define NO_ALPHATEST\n" },
 	{ "burn", "shaders/glsl/main.vp", "shaders/glsl/burn.fp", nullptr, nullptr, "#define SIMPLE\n#define NO_ALPHATEST\n" },
 	{ "stencil", "shaders/glsl/main.vp", "shaders/glsl/stencil.fp", nullptr, nullptr, "#define SIMPLE\n#define NO_ALPHATEST\n" },
+	{ "dithertrans", "shaders/glsl/main.vp", "shaders/glsl/main.fp", "shaders/glsl/func_normal.fp", "shaders/glsl/material_normal.fp", "#define NO_ALPHATEST\n#define DITHERTRANS\n" },
 };
 
 int DFrameBuffer::GetShaderCount()

src/common/rendering/hwrenderer/data/hw_vrmodes.cpp

@@ -146,11 +146,27 @@ float VREyeInfo::getShift() const
 	return vr_swap_eyes ? -res : res;
 }
 
-VSMatrix VREyeInfo::GetProjection(float fov, float aspectRatio, float fovRatio) const
+VSMatrix VREyeInfo::GetProjection(float fov, float aspectRatio, float fovRatio, bool iso_ortho) const
 {
 	VSMatrix result;
 
-	if (mShiftFactor == 0)
+	if (iso_ortho) // Orthographic projection for isometric viewpoint
+	{
+		double zNear = -3.0/fovRatio; // screen->GetZNear();
+		double zFar = screen->GetZFar();
+
+		double fH = tan(DEG2RAD(fov) / 2) / fovRatio;
+		double fW = fH * aspectRatio * mScaleFactor;
+		double left = -fW;
+		double right = fW;
+		double bottom = -fH;
+		double top = fH;
+
+		VSMatrix fmat(1);
+		fmat.ortho((float)left, (float)right, (float)bottom, (float)top, (float)zNear, (float)zFar);
+		return fmat;
+	}
+	else if (mShiftFactor == 0)
 	{
 		float fovy = (float)(2 * RAD2DEG(atan(tan(DEG2RAD(fov) / 2) / fovRatio)));
 		result.perspective(fovy, aspectRatio, screen->GetZNear(), screen->GetZFar());

src/common/rendering/hwrenderer/data/hw_vrmodes.h

@@ -27,7 +27,7 @@ struct VREyeInfo
 	float mShiftFactor;
 	float mScaleFactor;
 
-	VSMatrix GetProjection(float fov, float aspectRatio, float fovRatio) const;
+	VSMatrix GetProjection(float fov, float aspectRatio, float fovRatio, bool iso_ortho) const;
 	DVector3 GetViewShift(float yaw) const;
 private:
 	float getShift() const;