factor out all truecolor blending functions into their own source file (

#1230)

src/CMakeLists.txt

@@ -66,6 +66,7 @@ set(GAME_SOURCE_FILES
     i_sdlsound.c
     i_sound.c           i_sound.h
     i_timer.c           i_timer.h
+    i_truecolor.c       i_truecolor.h
     i_video.c           i_video.h
     i_videohr.c         i_videohr.h
     i_winmusic.c

src/Makefile.am

@@ -83,6 +83,7 @@ i_sdlmusic.c                               \
 i_sdlsound.c                               \
 i_sound.c            i_sound.h             \
 i_timer.c            i_timer.h             \
+i_truecolor.c        i_truecolor.h         \
 i_video.c            i_video.h             \
 i_videohr.c          i_videohr.h           \
 i_winmusic.c                               \

src/i_truecolor.c

@@ -0,0 +1,114 @@
+//
+// Copyright(C) 1993-1996 Id Software, Inc.
+// Copyright(C) 2005-2014 Simon Howard
+// Copyright(C) 2015-2024 Fabian Greffrath
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// DESCRIPTION:
+//	[crispy] Truecolor rendering
+//
+
+#include "config.h"
+
+#ifdef CRISPY_TRUECOLOR
+
+#include "crispy.h"
+#include "i_truecolor.h"
+
+const uint32_t (*blendfunc) (const uint32_t fg, const uint32_t bg) = I_BlendOverTranmap;
+
+typedef union
+{
+    uint32_t i;
+    struct {
+        uint8_t b;
+        uint8_t g;
+        uint8_t r;
+        uint8_t a;
+    };
+} tcpixel_t;
+
+const uint32_t I_BlendAdd (const uint32_t bg_i, const uint32_t fg_i)
+{
+    tcpixel_t bg, fg, ret;
+
+    bg.i = bg_i;
+    fg.i = fg_i;
+
+    ret.a = 0xFFU;
+    ret.r = MIN(bg.r + fg.r, 0xFFU);
+    ret.g = MIN(bg.g + fg.g, 0xFFU);
+    ret.b = MIN(bg.b + fg.b, 0xFFU);
+
+    return ret.i;
+}
+
+const uint32_t I_BlendDark (const uint32_t bg_i, const int d)
+{
+    tcpixel_t bg, ret;
+
+    bg.i = bg_i;
+
+    ret.a = 0xFFU;
+    ret.r = (bg.r * d) >> 8;
+    ret.g = (bg.g * d) >> 8;
+    ret.b = (bg.b * d) >> 8;
+
+    return ret.i;
+}
+
+const uint32_t I_BlendOver (const uint32_t bg_i, const uint32_t fg_i, const int amount)
+{
+    tcpixel_t bg, fg, ret;
+
+    bg.i = bg_i;
+    fg.i = fg_i;
+
+    ret.a = 0xFFU;
+    ret.r = (amount * fg.r + (0XFFU - amount) * bg.r) >> 8;
+    ret.g = (amount * fg.g + (0XFFU - amount) * bg.g) >> 8;
+    ret.b = (amount * fg.b + (0XFFU - amount) * bg.b) >> 8;
+
+    return ret.i;
+}
+
+// [crispy] TRANMAP blending emulation, used for Doom
+const uint32_t I_BlendOverTranmap (const uint32_t bg, const uint32_t fg)
+{
+    return I_BlendOver(bg, fg, 0xA8); // 168 (66% opacity)
+}
+
+// [crispy] TINTTAB blending emulation, used for Heretic and Hexen
+const uint32_t I_BlendOverTinttab (const uint32_t bg, const uint32_t fg)
+{
+    return I_BlendOver(bg, fg, 0x60); // 96 (38% opacity)
+}
+
+// [crispy] More opaque ("Alt") TINTTAB blending emulation, used for Hexen's MF_ALTSHADOW drawing
+const uint32_t I_BlendOverAltTinttab (const uint32_t bg, const uint32_t fg)
+{
+    return I_BlendOver(bg, fg, 0x8E); // 142 (56% opacity)
+}
+
+// [crispy] More opaque XLATAB blending emulation, used for Strife
+const uint32_t I_BlendOverXlatab (const uint32_t bg, const uint32_t fg)
+{
+    return I_BlendOver(bg, fg, 0xC0); // 192 (75% opacity)
+}
+
+// [crispy] Less opaque ("Alt") XLATAB blending emulation, used for Strife
+const uint32_t I_BlendOverAltXlatab (const uint32_t bg, const uint32_t fg)
+{
+    return I_BlendOver(bg, fg, 0x40); // 64 (25% opacity)
+}
+
+#endif

src/i_truecolor.h

@@ -0,0 +1,43 @@
+//
+// Copyright(C) 1993-1996 Id Software, Inc.
+// Copyright(C) 2005-2014 Simon Howard
+// Copyright(C) 2015-2024 Fabian Greffrath
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// DESCRIPTION:
+//	[crispy] Truecolor rendering
+//
+
+#ifndef __I_TRUECOLOR__
+#define __I_TRUECOLOR__
+
+#include "config.h"
+
+#ifdef CRISPY_TRUECOLOR
+
+#include <stdint.h>
+
+extern const uint32_t (*blendfunc) (const uint32_t fg, const uint32_t bg);
+
+const uint32_t I_BlendAdd (const uint32_t bg_i, const uint32_t fg_i);
+const uint32_t I_BlendDark (const uint32_t bg_i, const int d);
+const uint32_t I_BlendOver (const uint32_t bg_i, const uint32_t fg_i, const int amount);
+
+const uint32_t I_BlendOverTranmap (const uint32_t bg, const uint32_t fg);
+const uint32_t I_BlendOverTinttab (const uint32_t bg, const uint32_t fg);
+const uint32_t I_BlendOverAltTinttab (const uint32_t bg, const uint32_t fg);
+const uint32_t I_BlendOverXlatab (const uint32_t bg, const uint32_t fg);
+const uint32_t I_BlendOverAltXlatab (const uint32_t bg, const uint32_t fg);
+
+#endif
+
+#endif

src/i_video.c

@@ -2107,87 +2107,8 @@ void I_BindVideoVariables(void)
 }
 
 #ifdef CRISPY_TRUECOLOR
-#define amask (0xFF000000U)
-#define rmask (0x00FF0000U)
-#define gmask (0x0000FF00U)
-#define bmask (0x000000FFU)
-
-const pixel_t I_BlendAdd (const pixel_t bg, const pixel_t fg)
-{
-	uint32_t r, g, b;
-
-	if ((r = (fg & rmask) + (bg & rmask)) > rmask) r = rmask;
-	if ((g = (fg & gmask) + (bg & gmask)) > gmask) g = gmask;
-	if ((b = (fg & bmask) + (bg & bmask)) > bmask) b = bmask;
-
-	return amask | r | g | b;
-}
-
-// [crispy] http://stereopsis.com/doubleblend.html
-const pixel_t I_BlendDark (const pixel_t bg, const int d)
-{
-	const uint32_t ag = (bg & 0xff00ff00) >> 8;
-	const uint32_t rb =  bg & 0x00ff00ff;
-
-	uint32_t sag = d * ag;
-	uint32_t srb = d * rb;
-
-	sag = sag & 0xff00ff00;
-	srb = (srb >> 8) & 0x00ff00ff;
-
-	return amask | sag | srb;
-}
-
-// [crispy] Main overlay blending function
-const pixel_t I_BlendOver (const pixel_t bg, const pixel_t fg, const int amount)
-{
-	const uint32_t r = ((amount * (fg & rmask) + (0xff - amount) * (bg & rmask)) >> 8) & rmask;
-	const uint32_t g = ((amount * (fg & gmask) + (0xff - amount) * (bg & gmask)) >> 8) & gmask;
-	const uint32_t b = ((amount * (fg & bmask) + (0xff - amount) * (bg & bmask)) >> 8) & bmask;
-
-	return amask | r | g | b;
-}
-
-// [crispy] TRANMAP blending emulation, used for Doom
-const pixel_t I_BlendOverTranmap (const pixel_t bg, const pixel_t fg)
-{
-	return I_BlendOver(bg, fg, 0xA8); // 168 (66% opacity)
-}
-
-// [crispy] TINTTAB blending emulation, used for Heretic and Hexen
-const pixel_t I_BlendOverTinttab (const pixel_t bg, const pixel_t fg)
-{
-	return I_BlendOver(bg, fg, 0x60); // 96 (38% opacity)
-}
-
-// [crispy] More opaque ("Alt") TINTTAB blending emulation, used for Hexen's MF_ALTSHADOW drawing
-const pixel_t I_BlendOverAltTinttab (const pixel_t bg, const pixel_t fg)
-{
-	return I_BlendOver(bg, fg, 0x8E); // 142 (56% opacity)
-}
-
-// [crispy] More opaque XLATAB blending emulation, used for Strife
-const pixel_t I_BlendOverXlatab (const pixel_t bg, const pixel_t fg)
-{
-	return I_BlendOver(bg, fg, 0xC0); // 192 (75% opacity)
-}
-
-// [crispy] Less opaque ("Alt") XLATAB blending emulation, used for Strife
-const pixel_t I_BlendOverAltXlatab (const pixel_t bg, const pixel_t fg)
-{
-	return I_BlendOver(bg, fg, 0x40); // 64 (25% opacity)
-}
-
-const pixel_t (*blendfunc) (const pixel_t fg, const pixel_t bg) = I_BlendOverTranmap;
-
 const pixel_t I_MapRGB (const uint8_t r, const uint8_t g, const uint8_t b)
 {
-/*
-	return amask |
-	        (((r * rmask) >> 8) & rmask) |
-	        (((g * gmask) >> 8) & gmask) |
-	        (((b * bmask) >> 8) & bmask);
-*/
 	return SDL_MapRGB(argbbuffer->format, r, g, b);
 }
 #endif

src/i_video.h

@@ -21,6 +21,7 @@
 #define __I_VIDEO__
 
 #include "doomtype.h"
+#include "i_truecolor.h"
 #include "m_fixed.h" // [crispy] fixed_t
 #include "crispy.h"
 

src/v_trans.h

@@ -58,16 +58,6 @@ extern char **crstr;
 
 #ifndef CRISPY_TRUECOLOR
 extern byte *tranmap;
-#else
-extern const pixel_t (*blendfunc) (const pixel_t fg, const pixel_t bg);
-extern const pixel_t I_BlendAdd (const pixel_t bg, const pixel_t fg);
-extern const pixel_t I_BlendDark (const pixel_t bg, const int d);
-extern const pixel_t I_BlendOver (const pixel_t bg, const pixel_t fg, const int amount);
-extern const pixel_t I_BlendOverTranmap (const pixel_t bg, const pixel_t fg);
-extern const pixel_t I_BlendOverTinttab (const pixel_t bg, const pixel_t fg);
-extern const pixel_t I_BlendOverAltTinttab (const pixel_t bg, const pixel_t fg);
-extern const pixel_t I_BlendOverXlatab (const pixel_t bg, const pixel_t fg);
-extern const pixel_t I_BlendOverAltXlatab (const pixel_t bg, const pixel_t fg);
 #endif
 
 int V_GetPaletteIndex(byte *palette, int r, int g, int b);