Adding isometric camera mode with orthographic projection to current state of master branch of GZDoom.

src/common/filesystem/source/file_zip.cpp

@@ -35,6 +35,7 @@
 
 #include <time.h>
 #include <stdexcept>
+#include <cstdint>
 #include "w_zip.h"
 #include "ancientzip.h"
 #include "resourcefile.h"

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

@@ -54,3 +54,11 @@ 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_isocam)
+EXTERN_CVAR(Int, r_isoviewpoint)
+EXTERN_CVAR(Float, r_iso_camdist)
+EXTERN_CVAR(Float, r_iso_dist)
+EXTERN_CVAR(Float, r_iso_pitch)
+EXTERN_CVAR(Bool, r_drawplayersprites)
+EXTERN_CVAR(Bool, r_orthographic)

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 isocam) const
 {
 	VSMatrix result;
 
-	if (mShiftFactor == 0)
+	if (isocam) // Orthographic projection for isometric viewpoint
+	{
+		double zNear = -1.0; // screen->GetZNear();
+		double zFar = screen->GetZFar();
+
+		double fH = r_iso_dist * 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 isocam) const;
 	DVector3 GetViewShift(float yaw) const;
 private:
 	float getShift() const;

src/playsim/d_player.h

@@ -324,6 +324,9 @@ public:
 	// This only represents the thrust that the player applies himself.
 	// This avoids anomalies with such things as Boom ice and conveyors.
 	DVector2 Vel = { 0,0 };
+        // Used by isometric camera (% 8 cardinal directions) (See RenderViewpoint() in src/rendering/hwrenderer/hw_entrypoint.cpp)
+        int isoviewpoint = 1;
+        int isoyaw = 225; // degrees
 
 	bool		centering = false;
 	uint8_t		turnticks = 0;

src/playsim/p_user.cpp

@@ -270,6 +270,8 @@ void player_t::CopyFrom(player_t &p, bool copyPSP)
 	deltaviewheight = p.deltaviewheight;
 	bob = p.bob;
 	Vel = p.Vel;
+	isoviewpoint = p.isoviewpoint;
+	isoyaw = p.isoyaw;
 	centering = p.centering;
 	turnticks = p.turnticks;
 	attackdown = p.attackdown;
@@ -1635,6 +1637,8 @@ void player_t::Serialize(FSerializer &arc)
 		("deltaviewheight", deltaviewheight)
 		("bob", bob)
 		("vel", Vel)
+	        ("isoviewpoint", isoviewpoint)
+	        ("isoyaw", isoyaw)
 		("centering", centering)
 		("health", health)
 		("inventorytics", inventorytics)
@@ -1742,6 +1746,8 @@ DEFINE_FIELD_X(PlayerInfo, player_t, viewheight)
 DEFINE_FIELD_X(PlayerInfo, player_t, deltaviewheight)
 DEFINE_FIELD_X(PlayerInfo, player_t, bob)
 DEFINE_FIELD_X(PlayerInfo, player_t, Vel)
+DEFINE_FIELD_X(PlayerInfo, player_t, isoviewpoint)
+DEFINE_FIELD_X(PlayerInfo, player_t, isoyaw)
 DEFINE_FIELD_X(PlayerInfo, player_t, centering)
 DEFINE_FIELD_X(PlayerInfo, player_t, turnticks)
 DEFINE_FIELD_X(PlayerInfo, player_t, attackdown)

src/rendering/hwrenderer/hw_entrypoint.cpp

@@ -162,8 +162,37 @@ sector_t* RenderViewpoint(FRenderViewpoint& mainvp, AActor* camera, IntRect* bou
 
 		di->Viewpoint.FieldOfView = DAngle::fromDeg(fov);	// Set the real FOV for the current scene (it's not necessarily the same as the global setting in r_viewpoint)
 
-		// Stereo mode specific perspective projection
+		// Switch viewpoint for isometric camera
-		di->VPUniforms.mProjectionMatrix = eye.GetProjection(fov, ratio, fovratio);
+		if(r_isocam && camera->player != NULL)
+		{
+		        float camdist = r_iso_dist;
+			if (r_orthographic) camdist = r_iso_camdist;
+			float camheight = camdist*FAngle::fromDeg(r_iso_pitch).Tan();
+			camheight -= 0.5*camera->player->viewheight;
+			int myisoviewpoint = 1;
+			if (r_isoviewpoint > 0 && r_isoviewpoint < 9) myisoviewpoint = r_isoviewpoint - 1;
+			else myisoviewpoint = camera->player->isoviewpoint % 8;
+			if (myisoviewpoint < 0) myisoviewpoint = 0;
+			if (r_isoviewpoint < 9) camera->player->isoyaw = 45.0 * myisoviewpoint; // The eight cardinal directions
+			vp.Pos.X -= camdist * DAngle::fromDeg(camera->player->isoyaw).Cos();
+			vp.Pos.Y -= camdist * DAngle::fromDeg(camera->player->isoyaw).Sin();
+			vp.Pos.Z += camheight;
+			vp.HWAngles.Pitch = FAngle::fromDeg(r_iso_pitch);
+			vp.Angles.Pitch = DAngle::fromDeg(r_iso_pitch);
+			vp.Angles.Yaw = DAngle::fromDeg(camera->player->isoyaw);
+			vp.Angles.Roll = DAngle::fromDeg(0);
+			vp.showviewer = true; // Draw player sprite
+			r_drawplayersprites = false; // Don't draw first-person hands/weapons
+			// Stereo mode specific perspective projection
+			di->VPUniforms.mProjectionMatrix = eye.GetProjection(fov, ratio, fovratio, r_orthographic);
+		}
+		else // Regular first-person viewpoint
+		{
+		        vp.showviewer = false;
+			r_drawplayersprites = true; // Restore first-person hands/weapons
+			// Stereo mode specific perspective projection
+			di->VPUniforms.mProjectionMatrix = eye.GetProjection(fov, ratio, fovratio, false);
+		}
 		// Stereo mode specific viewpoint adjustment
 		vp.Pos += eye.GetViewShift(vp.HWAngles.Yaw.Degrees());
 		di->SetupView(RenderState, vp.Pos.X, vp.Pos.Y, vp.Pos.Z, false, false);

src/rendering/hwrenderer/scene/hw_sprites.cpp

@@ -477,7 +477,9 @@ bool HWSprite::CalculateVertices(HWDrawInfo* di, FVector3* v, DVector3* vp)
 			// Rotate the sprite about the vector starting at the center of the sprite
 			// triangle strip and with direction orthogonal to where the player is looking
 			// in the x/y plane.
+		        if(r_isocam) mat.Translate(0.0, z2 - zcenter, 0.0);
 			mat.Rotate(-sin(angleRad), 0, cos(angleRad), -HWAngles.Pitch.Degrees());
+			if(r_isocam) mat.Translate(0.0, zcenter - z2, 0.0);
 		}
 
 		mat.Translate(-center.X, -center.Z, -center.Y); // retreat from sprite center
@@ -900,6 +902,7 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 	{
 		bool mirror = false;
 		DAngle ang = (thingpos - vp.Pos).Angle();
+		if(r_isocam) ang = vp.Angles.Yaw;
 		FTextureID patch;
 		// [ZZ] add direct picnum override
 		if (isPicnumOverride)
@@ -1019,6 +1022,20 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 			x2 = x - viewvecY*rightfac;
 			y1 = y + viewvecX*leftfac;
 			y2 = y + viewvecX*rightfac;
+			if(thing->radius > 0 && r_isocam) // If sprites are drawn from an isometric perspective
+			{
+			        float signX = 1.0;
+				float signY = 1.0;
+				if(viewvecX < 0) signX = -1.0;
+				if(viewvecY < 0) signY = -1.0;
+				if(viewvecX == 0) signX = 0.0;
+				if(viewvecY == 0) signY = 0.0;
+
+				x1 -= signX * thing->radius;
+				x2 -= signX * thing->radius;
+				y1 -= signY * thing->radius;
+				y2 -= signY * thing->radius;
+			}
 			break;
 		}
 		case RF_FLATSPRITE:
@@ -1059,6 +1076,7 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 	}
 
 	depth = (float)((x - vp.Pos.X) * vp.TanCos + (y - vp.Pos.Y) * vp.TanSin);
+	if(r_isocam) depth = depth * vp.Angles.Pitch.Cos() - vp.Angles.Pitch.Sin() * z2; // Helps with stacking actors with small xy offsets
 	if (isSpriteShadow) depth += 1.f/65536.f; // always sort shadows behind the sprite.
 
 	// light calculation

src/rendering/r_utility.cpp

@@ -101,6 +101,35 @@ CVAR (Bool, r_deathcamera, false, CVAR_ARCHIVE)
 CVAR (Int, r_clearbuffer, 0, 0)
 CVAR (Bool, r_drawvoxels, true, 0)
 CVAR (Bool, r_drawplayersprites, true, 0)	// [RH] Draw player sprites?
+CVARD (Bool, r_isocam, false,  CVAR_ARCHIVE | CVAR_SERVERINFO | CVAR_CHEAT, "render from isometric viewpoint.")
+CVARD (Bool, r_orthographic, true, CVAR_ARCHIVE | CVAR_SERVERINFO | CVAR_CHEAT, "render orthographic projection. Only used with r_isocam")
+CUSTOM_CVARD(Float, r_iso_pitch, 30.0f, CVAR_ARCHIVE | CVAR_SERVERINFO | CVAR_CHEAT, "pitch for isometric camera: 0 to 89 degrees.")
+{
+  if (self < 0.f)
+    self = 0.f;
+	else if (self > 89.f)
+    self = 89.f;
+}
+CUSTOM_CVAR(Float, r_iso_camdist, 1000.0f, CVAR_ARCHIVE | CVAR_SERVERINFO | CVAR_CHEAT)
+{
+  // Keep this large to avoid texture clipping, not used if r_orthographic is false
+  if (self < 1000.f)
+    self = 1000.f;
+}
+CUSTOM_CVARD(Int, r_isoviewpoint, 0, CVAR_ARCHIVE, "Isometric viewpoint angle. 1 to 8 for cardinal directions. 0 for ignore and use player->isoviewpoint. 9 for continuous use player->isoyaw.")
+{
+	if (self < 0)
+		self = 0;
+	else if (self > 9)
+		self = 9;
+}
+CUSTOM_CVARD(Float, r_iso_dist, 300.0, CVAR_ARCHIVE | CVAR_SERVERINFO | CVAR_CHEAT, "how far the isometric camera (r_isocam) is in the XY plane")
+{
+	if (self < 0.f)
+		self = 0.f;
+	else if (self > 1000.f)
+		self = 1000.f;
+}
 CUSTOM_CVAR(Float, r_quakeintensity, 1.0f, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 {
 	if (self < 0.f) self = 0.f;

wadsrc/static/zscript/actors/player/player.zs

@@ -2744,6 +2744,8 @@ struct PlayerInfo native play	// self is what internally is known as player_t
 	native double deltaviewheight;
 	native double bob;
 	native vector2 vel;
+	native int isoviewpoint;
+	native int isoyaw;
 	native bool centering;
 	native uint8 turnticks;
 	native bool attackdown;