porting back some changes from the GBA version

[voxscape] / src / voxscape.c

diff --git a/src/voxscape.c b/src/voxscape.c
index 54c0b10..c10b170 100644 (file)
--- a/src/voxscape.c
+++ b/src/voxscape.c
@@ -27,6 +27,8 @@ struct voxscape {
 
        int hfilt, cfilt;
 
+       int hscale;
+
        /* framebuffer */
        uint32_t *fb;
        int fbwidth, fbheight;
@@ -41,7 +43,7 @@ struct voxscape {
        int fov, znear, zfar;
        int nslices;
        int32_t *slicelen;
-       int proj_dist;
+       int *projlut;
 
        int zfog;       /* fog start Z (0: no fog) */
        int fogcolor[3];
@@ -80,7 +82,7 @@ struct voxscape *vox_create(int xsz, int ysz)
        }
 
        vox->vheight = 80;
-       vox->proj_dist = 4;     /* TODO */
+       vox->hscale = 140;
 
        return vox;
 }
@@ -205,7 +207,7 @@ void vox_filter(struct voxscape *vox, int hfilt, int cfilt)
        vox->cfilt = cfilt;
 }
 
-void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb, int horizon)
+void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
 {
        if(xres != vox->fbwidth) {
                free(vox->coltop);
@@ -217,10 +219,9 @@ void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb, int ho
        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)
+void vox_view(struct voxscape *vox, int32_t x, int32_t y, int h, int32_t angle, int32_t vangle)
 {
        if(h < 0) {
                h = vox_height(vox, x, y) - h;
@@ -231,14 +232,17 @@ void vox_view(struct voxscape *vox, int32_t x, int32_t y, int h, int32_t angle)
        vox->vheight = h;
        vox->angle = angle;
 
+       vox->horizon = (vox->fbheight * ((vangle + 0x10000) >> 1)) >> 16;
+
        vox->valid &= ~SLICELEN;
 }
 
-void vox_proj(struct voxscape *vox, int fov, int znear, int zfar)
+void vox_proj(struct voxscape *vox, int hscale, int fov, int znear, int zfar)
 {
        vox->fov = fov;
        vox->znear = znear;
        vox->zfar = zfar;
+       vox->hscale = hscale;
 
        vox->nslices = vox->zfar - vox->znear;
        free(vox->slicelen);
@@ -246,6 +250,12 @@ void vox_proj(struct voxscape *vox, int fov, int znear, int zfar)
                fprintf(stderr, "vox_proj: failed to allocate slice length table (%d)\n", vox->nslices);
                return;
        }
+       free(vox->projlut);
+       if(!(vox->projlut = malloc(vox->nslices * sizeof *vox->projlut))) {
+               fprintf(stderr, "vox_proj: failed to allocate projection table (%d)\n", vox->nslices);
+               free(vox->slicelen);
+               return;
+       }
 
        vox->valid &= ~SLICELEN;
 }
@@ -276,6 +286,7 @@ void vox_begin(struct voxscape *vox)
                float theta = (float)vox->fov * M_PI / 360.0f;  /* half angle */
                for(i=0; i<vox->nslices; i++) {
                        vox->slicelen[i] = (int32_t)((vox->znear + i) * tan(theta) * 4.0f * 65536.0f);
+                       vox->projlut[i] = (vox->hscale << 8) / (vox->znear + i);
                }
                vox->valid |= SLICELEN;
        }
@@ -304,7 +315,7 @@ void vox_render_slice(struct voxscape *vox, int n)
        y = vox->y + COS(vox->angle) * z - ystep * (vox->fbwidth >> 1);
        for(i=0; i<vox->fbwidth; i++) {
                hval = vox_height(vox, x, y) - vox->vheight;
-               hval = hval * 160 / (vox->znear + n) + vox->horizon;
+               hval = ((hval * vox->projlut[n]) >> 8) + vox->horizon;
                if(hval > vox->fbheight) hval = vox->fbheight;
                if(hval > vox->coltop[i]) {
                        color = vox_color(vox, x, y);
@@ -360,6 +371,7 @@ void vox_sky_grad(struct voxscape *vox, uint32_t chor, uint32_t ctop)
        r1 = chor & 0xff;
 
        for(i=0; i<d; i++) {
+               if(i >= vox->fbheight) break;
                t = (i << 16) / d;
                grad[i] = lerp_rgb(r0, g0, b0, r1, g1, b1, t);
        }