From: John Tsiombikas <nuclear@member.fsf.org>
Date: Mon, 17 Oct 2022 21:32:12 +0000 (+0300)
Subject: fix red/blue order (imago reads BGRA, output expects RGBA)
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=voxscape;a=commitdiff_plain;h=e10cd82c8f0b2a2140aa6a4792ed56329932271f

fix red/blue order (imago reads BGRA, output expects RGBA)
---

diff --git a/src/voxscape.c b/src/voxscape.c
index 7d39a8b..54c0b10 100644
--- a/src/voxscape.c
+++ b/src/voxscape.c
@@ -116,8 +116,10 @@ struct voxscape *vox_open(const char *hfile, const char *cfile)
 
 	memcpy(vox->height, hpix, width * height);
 
+	/* swap r/b and discard alpha while copying */
 	for(i=0; i<width*height; i++) {
-		vox->color[i] = cpix[i] & 0xffffff;	/* discard alpha */
+		vox->color[i] = (cpix[i] & 0xff00) | ((cpix[i] & 0xff) << 16) |
+			((cpix[i] & 0xff0000) >> 16);
 	}
 
 	img_free_pixels(hpix);
@@ -141,9 +143,9 @@ void vox_fog(struct voxscape *vox, int zstart, uint32_t color)
 {
 	vox->zfog = zstart;
 
-	vox->fogcolor[0] = color >> 16;
+	vox->fogcolor[2] = color >> 16;
 	vox->fogcolor[1] = (color >> 8) & 0xff;
-	vox->fogcolor[2] = color & 0xff;
+	vox->fogcolor[0] = color & 0xff;
 }
 
 #define H(x, y)	\
@@ -350,12 +352,12 @@ void vox_sky_grad(struct voxscape *vox, uint32_t chor, uint32_t ctop)
 
 	grad = alloca(vox->fbheight * sizeof *grad);
 
-	r0 = ctop >> 16;
+	b0 = ctop >> 16;
 	g0 = (ctop >> 8) & 0xff;
-	b0 = ctop & 0xff;
-	r1 = chor >> 16;
+	r0 = ctop & 0xff;
+	b1 = chor >> 16;
 	g1 = (chor >> 8) & 0xff;
-	b1 = chor & 0xff;
+	r1 = chor & 0xff;
 
 	for(i=0; i<d; i++) {
 		t = (i << 16) / d;
@@ -380,28 +382,28 @@ static uint32_t lerp_rgb(int r0, int g0, int b0, int r1, int g1, int b1, int32_t
 	int r = XLERP(r0, r1, t, 16);
 	int g = XLERP(g0, g1, t, 16);
 	int b = XLERP(b0, b1, t, 16);
-	return (r << 16) | (g << 8) | b;
+	return (b << 16) | (g << 8) | r;
 }
 
 static uint32_t lerp_color(uint32_t ca, uint32_t cb, int32_t t)
 {
 	int r0, g0, b0, r1, g1, b1;
 
-	r0 = ca >> 16;
+	b0 = ca >> 16;
 	g0 = (ca >> 8) & 0xff;
-	b0 = ca & 0xff;
-	r1 = cb >> 16;
+	r0 = ca & 0xff;
+	b1 = cb >> 16;
 	g1 = (cb >> 8) & 0xff;
-	b1 = cb & 0xff;
+	r1 = cb & 0xff;
 
 	return lerp_rgb(r0, g0, b0, r1, g1, b1, t);
 }
 
 static uint32_t lerp_pcol_rgb(uint32_t pcol, int r, int g, int b, int32_t t)
 {
-	int r0 = pcol >> 16;
+	int b0 = pcol >> 16;
 	int g0 = (pcol >> 8) & 0xff;
-	int b0 = pcol & 0xff;
+	int r0 = pcol & 0xff;
 
 	return lerp_rgb(r0, g0, b0, r, g, b, t);
 }