From: divverent <divverent@d7cf8633-e32d-0410-b094-e92efae38249>
Date: Sat, 11 Oct 2008 15:06:28 +0000 (+0000)
Subject: add DRAWFLAG_SCREEN (which basically is like invert-modulate-invert, equivalent to... 
X-Git-Tag: xonotic-v0.1.0preview~2060
X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=commitdiff_plain;h=971ad66cc21064832305abca4e356213dd513d9b

add DRAWFLAG_SCREEN (which basically is like invert-modulate-invert, equivalent to GIMP's "screen" layer operation, no idea how photoshop calls it)
Just like modulate always darkens, screen always brightens.


git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@8528 d7cf8633-e32d-0410-b094-e92efae38249
---

diff --git a/clvm_cmds.c b/clvm_cmds.c
index 656fbc4e..0d30689c 100644
--- a/clvm_cmds.c
+++ b/clvm_cmds.c
@@ -2480,12 +2480,16 @@ static void VM_DrawPolygonCallback (const entity_render_t *ent, const rtlight_t
 		int numtriangles = 0;
 		rtexture_t *tex = polys->data_triangles[surfacelist[surfacelistindex]].texture;
 		int drawflag = polys->data_triangles[surfacelist[surfacelistindex]].drawflag;
+		// this can't call _DrawQ_ProcessDrawFlag, but should be in sync with it
+		// FIXME factor this out
 		if(drawflag == DRAWFLAG_ADDITIVE)
 			GL_BlendFunc(GL_SRC_ALPHA, GL_ONE);
 		else if(drawflag == DRAWFLAG_MODULATE)
 			GL_BlendFunc(GL_DST_COLOR, GL_ZERO);
 		else if(drawflag == DRAWFLAG_2XMODULATE)
 			GL_BlendFunc(GL_DST_COLOR,GL_SRC_COLOR);
+		else if(drawflag == DRAWFLAG_SCREEN)
+			GL_BlendFunc(GL_ONE_MINUS_DST_COLOR,GL_ONE);
 		else
 			GL_BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 		R_Mesh_TexBind(0, R_GetTexture(tex));
diff --git a/draw.h b/draw.h
index c9c8b745..88b3d5a1 100644
--- a/draw.h
+++ b/draw.h
@@ -76,6 +76,7 @@ DRAWFLAG_NORMAL,
 DRAWFLAG_ADDITIVE,
 DRAWFLAG_MODULATE,
 DRAWFLAG_2XMODULATE,
+DRAWFLAG_SCREEN,
 DRAWFLAG_NUMFLAGS,
 DRAWFLAG_MASK = 0xFF,   // ONLY R_BeginPolygon()
 DRAWFLAG_MIPMAP = 0x100 // ONLY R_BeginPolygon()
diff --git a/gl_draw.c b/gl_draw.c
index 468a1624..9d3d47b5 100644
--- a/gl_draw.c
+++ b/gl_draw.c
@@ -813,6 +813,8 @@ static void _DrawQ_ProcessDrawFlag(int flags)
 		GL_BlendFunc(GL_DST_COLOR, GL_ZERO);
 	else if(flags == DRAWFLAG_2XMODULATE)
 		GL_BlendFunc(GL_DST_COLOR,GL_SRC_COLOR);
+	else if(flags == DRAWFLAG_SCREEN)
+		GL_BlendFunc(GL_ONE_MINUS_DST_COLOR,GL_ONE);
 	else
 		GL_BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 }