From: techflashYT <officialTechflashYT@gmail.com>
Date: Sat, 12 Jul 2025 12:10:37 +0000 (-0700)
Subject: Add support for specifying the color mode
X-Git-Url: https://git.0x19.co/screenshots/ubuntu.png?a=commitdiff_plain;h=16bf927ffb10f963183bbfdbf0c775e92b82f8d8;p=doomgeneric-snom360

Add support for specifying the color mode

This allows for changing the color mode, rather than the currently
hardcoded always RGBA8888.  That default is preserved for compatibility,
but this allows also specifying RGB565, and is extensible to allow more
modes later on.
---

diff --git a/doomgeneric/i_video.c b/doomgeneric/i_video.c
index 8a9aac6..dd6f716 100644
--- a/doomgeneric/i_video.c
+++ b/doomgeneric/i_video.c
@@ -181,7 +181,8 @@ void cmap_to_fb(uint8_t * out, uint8_t * in, int in_pixels)
 
 void I_InitGraphics (void)
 {
-    int i;
+    int i, gfxmodeparm;
+    char *mode;
 
 	memset(&s_Fb, 0, sizeof(struct FB_ScreenInfo));
 	s_Fb.xres = DOOMGENERIC_RESX;
@@ -195,18 +196,49 @@ void I_InitGraphics (void)
 
 #else  // CMAP256
 
-	s_Fb.bits_per_pixel = 32;
+	gfxmodeparm = M_CheckParmWithArgs("-gfxmode", 1);
+
+	if (gfxmodeparm) {
+		mode = myargv[gfxmodeparm + 1];
+	}
+	else {
+		// default to rgba8888 like the old behavior, for compatibility
+		// maybe could warn here?
+		mode = "rgba8888";
+	}
+
+	if (strcmp(mode, "rgba8888") == 0) {
+		// default mode
+		s_Fb.bits_per_pixel = 32;
+
+		s_Fb.blue.length = 8;
+		s_Fb.green.length = 8;
+		s_Fb.red.length = 8;
+		s_Fb.transp.length = 8;
+
+		s_Fb.blue.offset = 0;
+		s_Fb.green.offset = 8;
+		s_Fb.red.offset = 16;
+		s_Fb.transp.offset = 24;
+	}
+
+	else if (strcmp(mode, "rgb565") == 0) {
+		s_Fb.bits_per_pixel = 16;
+
+		s_Fb.blue.length = 5;
+		s_Fb.green.length = 6;
+		s_Fb.red.length = 5;
+		s_Fb.transp.length = 0;
+
+		s_Fb.blue.offset = 11;
+		s_Fb.green.offset = 5;
+		s_Fb.red.offset = 0;
+		s_Fb.transp.offset = 16;
+	}
+	else
+		I_Error("Unknown gfxmode value: %s\n", mode);
 
-	s_Fb.blue.length = 8;
-	s_Fb.green.length = 8;
-	s_Fb.red.length = 8;
-	s_Fb.transp.length = 8;
 
-	s_Fb.blue.offset = 0;
-	s_Fb.green.offset = 8;
-	s_Fb.red.offset = 16;
-	s_Fb.transp.offset = 24;
-	
 #endif  // CMAP256
 
     printf("I_InitGraphics: framebuffer: x_res: %d, y_res: %d, x_virtual: %d, y_virtual: %d, bpp: %d\n",