#include <string.h>
#include <stdint.h>
#include <math.h>
+#include <assert.h>
#include <imago2.h>
#include "voxscape.h"
+#include "lut.h"
+
+#define XLERP(a, b, t, fp) \
+ ((((a) << (fp)) + ((b) - (a)) * (t)) >> fp)
+
+static uint32_t lerp_rgb(int r0, int g0, int b0, int r1, int g1, int b1, int32_t t);
+static uint32_t lerp_color(uint32_t ca, uint32_t cb, int32_t t);
+static uint32_t lerp_pcol_rgb(uint32_t pcol, int r, int g, int b, int32_t t);
enum {
SLICELEN = 1
int xsz, ysz;
unsigned char *height;
uint32_t *color;
+ int xshift, xmask, ymask;
+
+ int hfilt, cfilt;
/* framebuffer */
uint32_t *fb;
int fbwidth, fbheight;
int *coltop;
+ int horizon;
/* view */
int32_t x, y, angle;
+ int vheight;
/* projection */
int fov, znear, zfar;
int nslices;
- int32_t *slicelen; /* 24.8 */
+ int32_t *slicelen;
+ int proj_dist;
+
+ int zfog; /* fog start Z (0: no fog) */
+ int fogcolor[3];
unsigned int valid;
};
vox->xsz = xsz;
vox->ysz = ysz;
+ vox->xmask = vox->xsz - 1;
+ vox->ymask = vox->ysz - 1;
+
+ vox->xshift = -1;
+ while(xsz) {
+ xsz >>= 1;
+ vox->xshift++;
+ }
+
+ vox->vheight = 80;
+ vox->proj_dist = 4; /* TODO */
+
return vox;
}
{
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))) {
img_free_pixels(cpix);
return 0;
}
+
memcpy(vox->height, hpix, width * height);
- memcpy(vox->color, cpix, width * height * sizeof *vox->color);
+
+ /* swap r/b and discard alpha while copying */
+ for(i=0; i<width*height; i++) {
+ vox->color[i] = (cpix[i] & 0xff00) | ((cpix[i] & 0xff) << 16) |
+ ((cpix[i] & 0xff0000) >> 16);
+ }
img_free_pixels(hpix);
img_free_pixels(cpix);
free(vox);
}
-void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
+void vox_fog(struct voxscape *vox, int zstart, uint32_t color)
+{
+ vox->zfog = zstart;
+
+ vox->fogcolor[2] = color >> 16;
+ vox->fogcolor[1] = (color >> 8) & 0xff;
+ vox->fogcolor[0] = color & 0xff;
+}
+
+#define H(x, y) \
+ vox->height[((((y) >> 16) & vox->ymask) << vox->xshift) + (((x) >> 16) & vox->xmask)]
+#define C(x, y) \
+ vox->color[((((y) >> 16) & vox->ymask) << vox->xshift) + (((x) >> 16) & vox->xmask)]
+
+
+int vox_height(struct voxscape *vox, int32_t x, int32_t y)
+{
+ int32_t u, v;
+ int h00, h01, h10, h11, h0, h1;
+
+ if(!vox->hfilt) {
+ return H(x, y);
+ }
+
+ h00 = H(x, y);
+ h01 = H(x, y + 0x10000);
+ h10 = H(x + 0x10000, y);
+ h11 = H(x + 0x10000, y + 0x10000);
+
+ u = x & 0xffff;
+ v = y & 0xffff;
+
+ h0 = XLERP(h00, h01, v, 16);
+ h1 = XLERP(h10, h11, v, 16);
+ return XLERP(h0, h1, u, 16);
+}
+
+int vox_color(struct voxscape *vox, int32_t x, int32_t y)
+{
+ int32_t u, v;
+ uint32_t c00, c01, c10, c11, c0, c1;
+
+ if(!vox->cfilt) {
+ return C(x, y);
+ }
+
+ c00 = C(x, y);
+ c01 = C(x, y + 0x10000);
+ c10 = C(x + 0x10000, y);
+ c11 = C(x + 0x10000, y + 0x10000);
+
+ u = x & 0xffff;
+ v = y & 0xffff;
+
+ c0 = lerp_color(c00, c01, v);
+ c1 = lerp_color(c10, c11, v);
+ return lerp_color(c0, c1, u);
+}
+
+
+void vox_filter(struct voxscape *vox, int hfilt, int cfilt)
+{
+ vox->hfilt = hfilt;
+ vox->cfilt = cfilt;
+}
+
+void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb, int horizon)
{
if(xres != vox->fbwidth) {
free(vox->coltop);
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, 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 */
- valid &= ~SLICELEN;
+ vox->valid &= ~SLICELEN;
}
void vox_proj(struct voxscape *vox, int fov, int znear, int zfar)
{
- int i;
-
vox->fov = fov;
vox->znear = znear;
vox->zfar = zfar;
return;
}
- valid &= ~SLICELEN;
+ vox->valid &= ~SLICELEN;
}
/* algorithm:
{
int i;
- for(i=0; i<vox->fbwidth; i++) {
- vox->coltop[i] = vox->fbheight;
- }
+ memset(vox->coltop, 0, vox->fbwidth * sizeof *vox->coltop);
if(!(vox->valid & SLICELEN)) {
- float theta = (float)vox->angle * M_PI / 360.0f; /* half angle */
+ 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) * 2.0f * 256.0f)
+ vox->slicelen[i] = (int32_t)((vox->znear + i) * tan(theta) * 4.0f * 65536.0f);
}
vox->valid |= SLICELEN;
}
void vox_render_slice(struct voxscape *vox, int n)
{
- int32_t len;
+ int i, j, hval, colstart, colheight, z;
+ 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) << 16) / (vox->zfar - vox->zfog);
+ } else {
+ fog = 0;
+ }
+
+ z = vox->znear + n;
+
+ len = vox->slicelen[n] >> 8;
+ xstep = ((COS(vox->angle) >> 8) * len) / vox->fbwidth;
+ ystep = ((SIN(vox->angle) >> 8) * len) / vox->fbwidth;
+
+ x = vox->x - SIN(vox->angle) * z - xstep * (vox->fbwidth >> 1);
+ 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;
+ if(hval > vox->fbheight) hval = vox->fbheight;
+ if(hval > vox->coltop[i]) {
+ color = vox_color(vox, x, y);
+ colstart = vox->fbheight - hval;
+ colheight = hval - vox->coltop[i];
+ fbptr = vox->fb + colstart * vox->fbwidth + i;
+
+ if(fog > 0) {
+ color = lerp_pcol_rgb(color, vox->fogcolor[0], vox->fogcolor[1], vox->fogcolor[2], fog);
+ }
+
+ for(j=0; j<colheight; j++) {
+ *fbptr = color;
+ fbptr += vox->fbwidth;
+ }
+ vox->coltop[i] = hval;
+ }
- len = vox->slicelen[n];
+ x += xstep;
+ y += ystep;
+ }
+}
- /* TODO cont. */
+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;
+ int d = vox->fbheight - vox->horizon;
+ uint32_t *grad, *fbptr;
+
+ grad = alloca(vox->fbheight * sizeof *grad);
+
+ b0 = ctop >> 16;
+ g0 = (ctop >> 8) & 0xff;
+ r0 = ctop & 0xff;
+ b1 = chor >> 16;
+ g1 = (chor >> 8) & 0xff;
+ r1 = chor & 0xff;
+
+ for(i=0; i<d; i++) {
+ t = (i << 16) / d;
+ grad[i] = lerp_rgb(r0, g0, b0, r1, g1, b1, t);
+ }
+ for(i=d; i<vox->fbheight; i++) {
+ grad[i] = chor;
+ }
+
+ for(i=0; i<vox->fbwidth; i++) {
+ fbptr = vox->fb + i;
+ colheight = vox->fbheight - vox->coltop[i];
+ for(j=0; j<colheight; j++) {
+ *fbptr = grad[j];
+ fbptr += vox->fbwidth;
+ }
+ }
+}
+
+static uint32_t lerp_rgb(int r0, int g0, int b0, int r1, int g1, int b1, int32_t t)
+{
+ int r = XLERP(r0, r1, t, 16);
+ int g = XLERP(g0, g1, t, 16);
+ int b = XLERP(b0, b1, t, 16);
+ 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;
+
+ b0 = ca >> 16;
+ g0 = (ca >> 8) & 0xff;
+ r0 = ca & 0xff;
+ b1 = cb >> 16;
+ g1 = (cb >> 8) & 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 b0 = pcol >> 16;
+ int g0 = (pcol >> 8) & 0xff;
+ int r0 = pcol & 0xff;
+
+ return lerp_rgb(r0, g0, b0, r, g, b, t);
+}
+
projects / voxscape / blobdiff