foo

diff --git a/Makefile b/Makefile
index 816dbac..2859bb3 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ warn = -pedantic -Wall
 dbg = -g
 
 CFLAGS = $(warn) $(opt) $(dbg) -MMD
-LDFLAGS = -lGL -lglut -lm
+LDFLAGS = -lGL -lglut -lm -limago
 
 $(bin): $(obj)
        $(CC) -o $@ $(obj) $(LDFLAGS)

diff --git a/src/glfb.c b/src/glfb.c
index c60715d..a939ba6 100644 (file)
--- a/src/glfb.c
+++ b/src/glfb.c
@@ -98,13 +98,16 @@ void glfb_update(void *pixels)
 
 void glfb_display(void)
 {
+       glClearColor(0.2, 0.2, 0.2, 1);
+       glClear(GL_COLOR_BUFFER_BIT);
+
        glBegin(GL_TRIANGLES);
        glTexCoord2f(0, 0);
        glVertex2f(-1, -1);
        glTexCoord2f(tex_sx * 2.0f, 0);
-       glVertex2f(4, -1);
+       glVertex2f(3, -1);
        glTexCoord2f(0, tex_sy * 2.0f);
-       glVertex2f(-1, 4);
+       glVertex2f(-1, 3);
        glEnd();
 }
 

diff --git a/src/main.c b/src/main.c
index a2440af..5569ae6 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -5,8 +5,10 @@
 #include <assert.h>
 #include <GL/glut.h>
 #include "glfb.h"
+#include "voxscape.h"
 
 int init(void);
+void cleanup(void);
 void display(void);
 void idle(void);
 void reshape(int x, int y);
@@ -18,6 +20,8 @@ int win_width, win_height;
 #define FB_H   480
 unsigned int fb[FB_W * FB_H];
 
+struct voxscape *vox;
+
 
 int main(int argc, char **argv)
 {
@@ -34,6 +38,7 @@ int main(int argc, char **argv)
        if(init() == -1) {
                return 1;
        }
+       atexit(cleanup);
 
        glutMainLoop();
        return 0;
@@ -42,29 +47,26 @@ int main(int argc, char **argv)
 
 int init(void)
 {
-       int i, j, xor, r, g, b;
-       unsigned int *ptr;
-
-       ptr = fb;
-       for(i=0; i<FB_H; i++) {
-               for(j=0; j<FB_W; j++) {
-                       xor = i ^ j;
-                       r = (xor >> 1) & 0xff;
-                       g = xor & 0xff;
-                       b = (xor << 1) & 0xff;
-                       *ptr++ = b | (g << 8) | (r << 16);
-               }
+       if(!(vox = vox_open("data/height.png", "data/color.png"))) {
+               return -1;
        }
-
-       win_width = glutGet(GLUT_WINDOW_WIDTH);
-       win_height = glutGet(GLUT_WINDOW_HEIGHT);
+       vox_framebuf(vox, FB_W, FB_H, fb);
+       vox_proj(vox, 45, 5, 100);
+       vox_view(vox, 512, 512, 0);
 
        glfb_setup(FB_W, FB_H, GLFB_RGBA32, FB_W * 4);
        return 0;
 }
 
+void cleanup(void)
+{
+       vox_free(vox);
+}
+
 void display(void)
 {
+       vox_render(vox);
+
        glfb_update(fb);
        glfb_display();
 

diff --git a/src/voxscape.c b/src/voxscape.c
new file mode 100644 (file)
index 0000000..b9a18c3
--- /dev/null
+++ b/src/voxscape.c
@@ -0,0 +1,188 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <math.h>
+#include <imago2.h>
+#include "voxscape.h"
+
+enum {
+       SLICELEN        = 1
+};
+
+struct voxscape {
+       int xsz, ysz;
+       unsigned char *height;
+       uint32_t *color;
+
+       /* framebuffer */
+       uint32_t *fb;
+       int fbwidth, fbheight;
+       int *coltop;
+
+       /* view */
+       int32_t x, y, angle;
+
+       /* projection */
+       int fov, znear, zfar;
+       int nslices;
+       int32_t *slicelen;      /* 24.8 */
+
+       unsigned int valid;
+};
+
+struct voxscape *vox_create(int xsz, int ysz)
+{
+       struct voxscape *vox;
+
+       if(!(vox = calloc(1, sizeof *vox))) {
+               return 0;
+       }
+       if(!(vox->height = calloc(1, xsz * ysz))) {
+               fprintf(stderr, "vox_create: failed to allocate %dx%d heightmap\n", xsz, ysz);
+               free(vox);
+               return 0;
+       }
+       if(!(vox->color = calloc(xsz * ysz, sizeof *vox->color))) {
+               fprintf(stderr, "vox_create: failed to allocate %dx%d color map\n", xsz, ysz);
+               free(vox->height);
+               free(vox);
+               return 0;
+       }
+       vox->xsz = xsz;
+       vox->ysz = ysz;
+
+       return vox;
+}
+
+struct voxscape *vox_open(const char *hfile, const char *cfile)
+{
+       unsigned char *hpix;
+       uint32_t *cpix;
+       int width, height, cwidth, cheight;
+       struct voxscape *vox;
+
+       if(!(hpix = img_load_pixels(hfile, &width, &height, IMG_FMT_GREY8))) {
+               fprintf(stderr, "vox_open: failed to load heightmap: %s\n", hfile);
+               return 0;
+       }
+       if(!(cpix = img_load_pixels(cfile, &cwidth, &cheight, IMG_FMT_RGBA32))) {
+               fprintf(stderr, "vox_open: failed to load color map: %s\n", cfile);
+               img_free_pixels(hpix);
+               return 0;
+       }
+       if(cwidth != width || cheight != height) {
+               img_free_pixels(hpix);
+               img_free_pixels(cpix);
+               fprintf(stderr, "vox_open: %s and %s have different dimensions\n", hfile, cfile);
+               return 0;
+       }
+
+       if(!(vox = vox_create(width, height))) {
+               img_free_pixels(hpix);
+               img_free_pixels(cpix);
+               return 0;
+       }
+       memcpy(vox->height, hpix, width * height);
+       memcpy(vox->color, cpix, width * height * sizeof *vox->color);
+
+       img_free_pixels(hpix);
+       img_free_pixels(cpix);
+
+       return vox;
+}
+
+void vox_free(struct voxscape *vox)
+{
+       if(!vox) return;
+
+       free(vox->color);
+       free(vox->height);
+       free(vox->coltop);
+       free(vox->slicelen);
+       free(vox);
+}
+
+void vox_framebuf(struct voxscape *vox, int xres, int yres, uint32_t *fb)
+{
+       if(xres != vox->fbwidth) {
+               free(vox->coltop);
+               if(!(vox->coltop = malloc(xres * sizeof *vox->coltop))) {
+                       fprintf(stderr, "vox_framebuf: failed to allocate column table (%d)\n", xres);
+                       return;
+               }
+       }
+       vox->fb = fb;
+       vox->fbwidth = xres;
+       vox->fbheight = yres;
+}
+
+void vox_view(struct voxscape *vox, int32_t x, int32_t y, int32_t angle)
+{
+       vox->x = x;
+       vox->y = y;
+       vox->angle = angle;
+       /* TODO precalc stuff */
+
+       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;
+
+       vox->nslices = vox->zfar - vox->znear;
+       free(vox->slicelen);
+       if(!(vox->slicelen = malloc(vox->nslices * sizeof *vox->slicelen))) {
+               fprintf(stderr, "vox_proj: failed to allocate slice length table (%d)\n", vox->nslices);
+               return;
+       }
+
+       valid &= ~SLICELEN;
+}
+
+/* algorithm:
+ * calculate extents of horizontal equidistant line from the viewer based on fov
+ * for each column step along this line and compute height for each pixel
+ * fill the visible (top) part of each column
+ */
+
+void vox_render(struct voxscape *vox)
+{
+       int i;
+
+       vox_begin(vox);
+       for(i=0; i<vox->nslices; i++) {
+               vox_render_slice(vox, i);
+       }
+}
+
+void vox_begin(struct voxscape *vox)
+{
+       int i;
+
+       for(i=0; i<vox->fbwidth; i++) {
+               vox->coltop[i] = vox->fbheight;
+       }
+
+       if(!(vox->valid & SLICELEN)) {
+               float theta = (float)vox->angle * 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->valid |= SLICELEN;
+       }
+}
+
+void vox_render_slice(struct voxscape *vox, int n)
+{
+       int32_t len;
+
+       len = vox->slicelen[n];
+
+       /* TODO cont. */
+}

diff --git a/src/voxscape.h b/src/voxscape.h
new file mode 100644 (file)
index 0000000..bd7d3a1
--- /dev/null
+++ b/src/voxscape.h
@@ -0,0 +1,21 @@
+#ifndef VOXSCAPE_H_
+#define VOXSCAPE_H_
+
+#include <stdint.h>
+
+struct voxscape;
+
+struct voxscape *vox_create(int xsz, int ysz);
+struct voxscape *vox_open(const char *hfile, const char *cfile);
+void vox_free(struct voxscape *vox);
+
+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);
+void vox_proj(struct voxscape *vox, int fov, int znear, int zfar);
+
+void vox_render(struct voxscape *vox);
+
+void vox_begin(struct voxscape *vox);
+void vox_render_slice(struct voxscape *vox, int n);
+
+#endif /* VOXSCAPE_H_ */