X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Fvoxscape.c;h=60d80a041b05622035442e6271a5290a3f7ed138;hb=f18556d9f7174dfb6822a7a543732389e8d48bcd;hp=a23a851eaa1fa734fd6a878c06b099b19bafb551;hpb=34a5a35c6ba9aff4ae92475bfa8d3b398633d835;p=voxscape

diff --git a/src/voxscape.c b/src/voxscape.c
index a23a851..60d80a0 100644
--- a/src/voxscape.c
+++ b/src/voxscape.c
@@ -22,6 +22,7 @@ struct voxscape {
 	uint32_t *fb;
 	int fbwidth, fbheight;
 	int *coltop;
+	int horizon;
 
 	/* view */
 	int32_t x, y, angle;
@@ -33,6 +34,9 @@ struct voxscape {
 	int32_t *slicelen;
 	int proj_dist;
 
+	int zfog;	/* fog start Z (0: no fog) */
+	int fogcolor[3];
+
 	unsigned int valid;
 };
 
@@ -76,7 +80,7 @@ struct voxscape *vox_open(const char *hfile, const char *cfile)
 {
 	unsigned char *hpix;
 	uint32_t *cpix;
-	int width, height, cwidth, cheight;
+	int i, width, height, cwidth, cheight;
 	struct voxscape *vox;
 
 	if(!(hpix = img_load_pixels(hfile, &width, &height, IMG_FMT_GREY8))) {
@@ -100,8 +104,12 @@ struct voxscape *vox_open(const char *hfile, const char *cfile)
 		img_free_pixels(cpix);
 		return 0;
 	}
+
 	memcpy(vox->height, hpix, width * height);
-	memcpy(vox->color, cpix, width * height * sizeof *vox->color);
+
+	for(i=0; i<width*height; i++) {
+		vox->color[i] = cpix[i] & 0xffffff;	/* discard alpha */
+	}
 
 	img_free_pixels(hpix);
 	img_free_pixels(cpix);
@@ -120,6 +128,15 @@ void vox_free(struct voxscape *vox)
 	free(vox);
 }
 
+void vox_fog(struct voxscape *vox, int zstart, uint32_t color)
+{
+	vox->zfog = zstart;
+
+	vox->fogcolor[0] = color >> 16;
+	vox->fogcolor[1] = (color >> 8) & 0xff;
+	vox->fogcolor[2] = color & 0xff;
+}
+
 int vox_height(struct voxscape *vox, int32_t x, int32_t y)
 {
 	int tx = (x >> 16) & vox->xmask;
@@ -128,7 +145,7 @@ int vox_height(struct voxscape *vox, int32_t x, int32_t y)
 	return vox->height[(ty << vox->xshift) + tx];
 }
 
-void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
+void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb, int horizon)
 {
 	if(xres != vox->fbwidth) {
 		free(vox->coltop);
@@ -140,6 +157,7 @@ void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
 	vox->fb = fb;
 	vox->fbwidth = xres;
 	vox->fbheight = yres;
+	vox->horizon = horizon >= 0 ? horizon : vox->fbheight / 2;
 }
 
 void vox_view(struct voxscape *vox, int32_t x, int32_t y, int h, int32_t angle)
@@ -205,11 +223,17 @@ void vox_begin(struct voxscape *vox)
 
 void vox_render_slice(struct voxscape *vox, int n)
 {
-	int i, j, tx, ty, hval, colstart, colheight, z;
-	int32_t x, y, len, xstep, ystep;
+	int i, j, tx, ty, hval, colstart, colheight, z, r, g, b;
+	int32_t x, y, len, xstep, ystep, fog;
 	uint32_t color;
 	uint32_t *fbptr;
 
+	if(vox->zfog > 0 && n > vox->zfog) {
+		fog = ((n - vox->zfog) << 8) / (vox->zfar - vox->zfog);
+	} else {
+		fog = 0;
+	}
+
 	z = vox->znear + n;
 
 	len = vox->slicelen[n] >> 8;
@@ -223,7 +247,7 @@ void vox_render_slice(struct voxscape *vox, int n)
 		ty = (y >> 16) & vox->ymask;
 
 		hval = vox->height[(ty << vox->xshift) + tx] - vox->vheight;
-		hval = hval * 160 / (vox->znear + n) + 250;
+		hval = hval * 160 / (vox->znear + n) + vox->horizon;
 		if(hval > vox->fbheight) hval = vox->fbheight;
 		if(hval > vox->coltop[i]) {
 			color = vox->color[(ty << vox->xshift) + tx];
@@ -231,6 +255,16 @@ void vox_render_slice(struct voxscape *vox, int n)
 			colheight = hval - vox->coltop[i];
 			fbptr = vox->fb + colstart * vox->fbwidth + i;
 
+			if(fog > 0) {
+				r = color >> 16;
+				g = (color >> 8) & 0xff;
+				b = color & 0xff;
+				r = ((r << 8) + (vox->fogcolor[0] - r) * fog) >> 8;
+				g = ((g << 8) + (vox->fogcolor[1] - g) * fog) >> 8;
+				b = ((b << 8) + (vox->fogcolor[2] - b) * fog) >> 8;
+				color = (r << 16) | (g << 8) | b;
+			}
+
 			for(j=0; j<colheight; j++) {
 				*fbptr = color;
 				fbptr += vox->fbwidth;
@@ -243,11 +277,26 @@ void vox_render_slice(struct voxscape *vox, int n)
 	}
 }
 
+void vox_sky_solid(struct voxscape *vox, uint32_t color)
+{
+	int i, j, colheight;
+	uint32_t *fbptr;
+
+	for(i=0; i<vox->fbwidth; i++) {
+		fbptr = vox->fb + i;
+		colheight = vox->fbheight - vox->coltop[i];
+		for(j=0; j<colheight; j++) {
+			*fbptr = color;
+			fbptr += vox->fbwidth;
+		}
+	}
+}
+
 void vox_sky_grad(struct voxscape *vox, uint32_t chor, uint32_t ctop)
 {
 	int i, j, colheight, t;
 	int r0, g0, b0, r1, g1, b1, r, g, b;
-	int d = vox->fbheight - 250;
+	int d = vox->fbheight - vox->horizon;
 	uint32_t *grad, *fbptr;
 
 	grad = alloca(vox->fbheight * sizeof *grad);