From 338b404055ec3ca02fd8e6121ca0510ae9a3b4fc Mon Sep 17 00:00:00 2001
From: mittorn <mittorn@sibmail.com>
Date: Thu, 4 Apr 2019 10:27:18 +0700
Subject: [PATCH] ref_soft: clamp alpha values

---
 r_edge.c   | 11 +++++++++--
 r_glblit.c |  7 +++++++
 r_scan.c   | 10 ++++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/r_edge.c b/r_edge.c
index e8b73f8d..1ac231a4 100644
--- a/r_edge.c
+++ b/r_edge.c
@@ -996,6 +996,8 @@ Normal surface cached, texture mapped surface
 */
 void D_AlphaSurf (surf_t *s)
 {
+	int alpha;
+
 	d_zistepu = s->d_zistepu;
 	d_zistepv = s->d_zistepv;
 	d_ziorigin = s->d_ziorigin;
@@ -1052,13 +1054,16 @@ void D_AlphaSurf (surf_t *s)
 		miplevel = D_MipLevelForScale(s->nearzi * scale_for_mip * pface->texinfo->mipadjust);
 	}
 #endif
+	alpha = RI.currententity->curstate.renderamt * 7 / 255;
+	if( alpha <= 0 && RI.currententity->curstate.renderamt > 0 )
+		alpha = 1;
 
 	if (s->flags & SURF_DRAWTURB )
 	{
 		cacheblock = R_GetTexture(pface->texinfo->texture->gl_texturenum)->pixels[0];
 		cachewidth = 64;
 		D_CalcGradients (pface);
-		TurbulentZ8( s->spans, RI.currententity->curstate.renderamt * 7 / 255 );
+		TurbulentZ8( s->spans, alpha);
 	}
 	else
 	{
@@ -1070,12 +1075,14 @@ void D_AlphaSurf (surf_t *s)
 
 		D_CalcGradients (pface);
 
+
+
 		if( RI.currententity->curstate.rendermode == kRenderTransAlpha )
 			D_AlphaSpans16(s->spans);
 		else if( RI.currententity->curstate.rendermode == kRenderTransAdd )
 			D_AddSpans16(s->spans);
 		else
-			D_BlendSpans16(s->spans, RI.currententity->curstate.renderamt * 7 / 255 );
+			D_BlendSpans16(s->spans, alpha );
 	}
 
 	VectorCopy (world_transformed_modelorg,
diff --git a/r_glblit.c b/r_glblit.c
index 0c2fdf41..a73cac59 100644
--- a/r_glblit.c
+++ b/r_glblit.c
@@ -231,6 +231,13 @@ void R_BuildBlendMaps()
 				r = r1 * (7 - a) / 7 + (r2 << 2 | BIT(2)) * a / 7;
 				g = g1 * (7 - a) / 7 + (g2 << 3 | MASK(2)) * a / 7;
 				b = b1 * (7 - a) / 7 + (b2 << 3 | MASK(2)) * a / 7;
+				if( r > MASK(5) )
+					r = MASK(5);
+				if( g > MASK(6) )
+					g = MASK(6);
+				if( b > MASK(5) )
+					b = MASK(5);
+
 
 				ASSERT( b < 32 );
 				major = (((r >> 2) & MASK(3)) << 5) |( (( (g >> 3) & MASK(3)) << 2 )  )| (((b >> 3) & MASK(2)));
diff --git a/r_scan.c b/r_scan.c
index fa5855c3..18a72ac9 100644
--- a/r_scan.c
+++ b/r_scan.c
@@ -297,6 +297,11 @@ void TurbulentZ8 (espan_t *pspan, int alpha1)
 	float			sdivz16stepu, tdivz16stepu, zi16stepu;
 	alpha = alpha1;
 
+	if( alpha > 7 )
+		alpha = 7;
+	if( alpha == 0 )
+		return;
+
 	r_turb_turb = sintable + ((int)(gpGlobals->time*SPEED)&(CYCLE-1));
 
 	r_turb_sstep = 0;	// keep compiler happy
@@ -960,6 +965,11 @@ void D_BlendSpans16 (espan_t *pspan, int alpha)
 	int izi, izistep;
 	short *pz;
 
+	if( alpha > 7 )
+		alpha = 7;
+	if( alpha == 0 )
+		return;
+
 	sstep = 0;	// keep compiler happy
 	tstep = 0;	// ditto