From 1765e270d1dd3c26a548852589fee951ffd4fbc4 Mon Sep 17 00:00:00 2001
From: toaster <rollerorbital@gmail.com>
Date: Thu, 11 Apr 2024 22:12:21 +0100
Subject: [PATCH] V_DrawCustomFadeScreen fallback behaviour for Legacy GL

---
 src/d_main.cpp         | 11 +++++++++--
 src/hardware/hw_draw.c | 27 +++++++++++++++++++++++++++
 src/hardware/hw_main.h |  1 +
 src/v_video.cpp        |  8 +++++++-
 4 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/src/d_main.cpp b/src/d_main.cpp
index 87141c251..3b139029b 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -637,13 +637,17 @@ static bool D_Display(bool world)
 			}
 
 			// rhi: display the software framebuffer to the screen
-			if (rendermode == render_soft)
+			//if (rendermode == render_soft)
 			{
 				// TODO: THIS SHOULD IDEALLY BE IN REGULAR HUD CODE !!
 				// (st_stuff.c ST_Drawer, also duplicated in k_podium.c)
 				// Unfortunately this is the latest place we can do it
 				// If we could immediately tint the GPU data a lot
 				// of problems could be solved (including GL support)
+				// ---
+				// last minute toast edit: We need to run most of this so
+				// that the fallback GL behaviour activates at the right time
+
 				if (gamestate != GS_TITLESCREEN
 				&& G_GamestateUsesLevel() == true
 				&& lt_fade < 16)
@@ -668,7 +672,10 @@ static bool D_Display(bool world)
 					}
 				}
 
-				VID_DisplaySoftwareScreen();
+				if (rendermode == render_soft)
+				{
+					VID_DisplaySoftwareScreen();
+				}
 			}
 
 			if (lastdraw)
diff --git a/src/hardware/hw_draw.c b/src/hardware/hw_draw.c
index e4bd41f11..e8784a5c1 100644
--- a/src/hardware/hw_draw.c
+++ b/src/hardware/hw_draw.c
@@ -748,6 +748,33 @@ void HWR_EncoreInvertScreen(void)
 	HWD.pfnDrawPolygon(&Surf, v, 4, PF_NoTexture|PF_Invert|PF_NoDepthTest);
 }
 
+void HWR_DrawCustomFadeScreen(UINT8 color, UINT8 strength)
+{
+	FOutVector v[4];
+	FSurfaceInfo Surf;
+
+	v[0].x = v[3].x = -1.0f;
+	v[2].x = v[1].x =  1.0f;
+	v[0].y = v[1].y = -1.0f;
+	v[2].y = v[3].y =  1.0f;
+	v[0].z = v[1].z = v[2].z = v[3].z = 1.0f;
+
+	v[0].s = v[3].s = 0.0f;
+	v[2].s = v[1].s = 1.0f;
+	v[0].t = v[1].t = 1.0f;
+	v[2].t = v[3].t = 0.0f;
+
+	Surf.PolyColor.rgba = V_GetColor(color).rgba;
+
+	UINT16 workingstrength = (strength*12);
+	if (workingstrength > 0xFF)
+		Surf.PolyColor.s.alpha = 0xFF;
+	else
+		Surf.PolyColor.s.alpha = workingstrength;
+
+	HWD.pfnDrawPolygon(&Surf, v, 4, PF_NoTexture|PF_Modulated|PF_Translucent|PF_NoDepthTest);
+}
+
 // Very similar to HWR_DrawConsoleBack, except we draw from the middle(-ish) of the screen to the bottom.
 void HWR_DrawTutorialBack(UINT32 color, INT32 boxheight)
 {
diff --git a/src/hardware/hw_main.h b/src/hardware/hw_main.h
index a489c510c..2d5a530a7 100644
--- a/src/hardware/hw_main.h
+++ b/src/hardware/hw_main.h
@@ -34,6 +34,7 @@ void HWR_drawAMline(const fline_t *fl, INT32 color);
 void HWR_FadeScreenMenuBack(UINT16 color, UINT8 strength);
 void HWR_DrawConsoleBack(UINT32 color, INT32 height);
 void HWR_EncoreInvertScreen(void);
+void HWR_DrawCustomFadeScreen(UINT8 color, UINT8 strength);
 void HWR_DrawTutorialBack(UINT32 color, INT32 boxheight);
 void HWR_RenderSkyboxView(player_t *player);
 void HWR_RenderPlayerView(void);
diff --git a/src/v_video.cpp b/src/v_video.cpp
index 4cc0d1990..dfab8889e 100644
--- a/src/v_video.cpp
+++ b/src/v_video.cpp
@@ -1602,7 +1602,13 @@ void V_DrawCustomFadeScreen(const char *lump, UINT8 strength)
 #ifdef HWRENDER
 	if (rendermode != render_soft && rendermode != render_none)
 	{
-		//HWR_DrawCustomFadeScreen(color, strength);
+		HWR_DrawCustomFadeScreen(
+			(strcmp(lump, "FADEMAP1") != 0
+				? 31
+				: 0
+			),
+			strength
+		);
 		return;
 	}
 #endif