From 34a5a35c6ba9aff4ae92475bfa8d3b398633d835 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 16 Oct 2022 19:44:10 +0300
Subject: [PATCH] autoheight

---
 src/main.c     |    5 ++---
 src/voxscape.c |   20 ++++++++++++++++----
 src/voxscape.h |    5 ++++-
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/main.c b/src/main.c
index e05118b..2a5459a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -77,8 +77,7 @@ int init(void)
 		return -1;
 	}
 	vox_framebuf(vox, FB_W, FB_H, fb);
-	vox_proj(vox, 45, 1, 200);
-	vox_view(vox, pos[0], pos[1], angle);
+	vox_proj(vox, 45, 1, 300);
 
 	glfb_setup(FB_W, FB_H, GLFB_RGBA32, FB_W * 4);
 	return 0;
@@ -121,7 +120,7 @@ void update(void)
 		pos[1] -= right[1];
 	}
 
-	vox_view(vox, pos[0], pos[1], angle);
+	vox_view(vox, pos[0], pos[1], -30, angle);
 }
 
 void display(void)
diff --git a/src/voxscape.c b/src/voxscape.c
index 0ea8f06..a23a851 100644
--- a/src/voxscape.c
+++ b/src/voxscape.c
@@ -66,7 +66,7 @@ struct voxscape *vox_create(int xsz, int ysz)
 		vox->xshift++;
 	}
 
-	vox->vheight = 50;
+	vox->vheight = 80;
 	vox->proj_dist = 4;	/* TODO */
 
 	return vox;
@@ -120,6 +120,14 @@ void vox_free(struct voxscape *vox)
 	free(vox);
 }
 
+int vox_height(struct voxscape *vox, int32_t x, int32_t y)
+{
+	int tx = (x >> 16) & vox->xmask;
+	int ty = (y >> 16) & vox->ymask;
+
+	return vox->height[(ty << vox->xshift) + tx];
+}
+
 void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
 {
 	if(xres != vox->fbwidth) {
@@ -134,12 +142,16 @@ void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
 	vox->fbheight = yres;
 }
 
-void vox_view(struct voxscape *vox, int32_t x, int32_t y, int32_t angle)
+void vox_view(struct voxscape *vox, int32_t x, int32_t y, int h, int32_t angle)
 {
+	if(h < 0) {
+		h = vox_height(vox, x, y) - h;
+	}
+
 	vox->x = x;
 	vox->y = y;
+	vox->vheight = h;
 	vox->angle = angle;
-	/* TODO precalc stuff */
 
 	vox->valid &= ~SLICELEN;
 }
@@ -210,7 +222,7 @@ void vox_render_slice(struct voxscape *vox, int n)
 		tx = (x >> 16) & vox->xmask;
 		ty = (y >> 16) & vox->ymask;
 
-		hval = vox->height[(ty << vox->xshift) + tx] - 80;
+		hval = vox->height[(ty << vox->xshift) + tx] - vox->vheight;
 		hval = hval * 160 / (vox->znear + n) + 250;
 		if(hval > vox->fbheight) hval = vox->fbheight;
 		if(hval > vox->coltop[i]) {
diff --git a/src/voxscape.h b/src/voxscape.h
index c0e386f..1bbb03a 100644
--- a/src/voxscape.h
+++ b/src/voxscape.h
@@ -9,8 +9,11 @@ struct voxscape *vox_create(int xsz, int ysz);
 struct voxscape *vox_open(const char *hfile, const char *cfile);
 void vox_free(struct voxscape *vox);
 
+int vox_height(struct voxscape *vox, int32_t x, int32_t y);
+
 void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb);
-void vox_view(struct voxscape *vox, int32_t x, int32_t y, int32_t angle);
+/* negative height for auto at -h above terrain */
+void vox_view(struct voxscape *vox, int32_t x, int32_t y, int h, int32_t angle);
 void vox_proj(struct voxscape *vox, int fov, int znear, int zfar);
 
 void vox_render(struct voxscape *vox);
-- 
1.7.10.4