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-rw-r--r--camera.c77
-rw-r--r--doc/libgraphics.ms34
-rw-r--r--doc/libgraphics.pdfbin0 -> 15087 bytes
-rw-r--r--doc/libgraphics.ps583
-rw-r--r--doc/mkfile15
-rw-r--r--graphics.h42
-rw-r--r--mkfile12
-rw-r--r--readme6
-rw-r--r--render.c135
9 files changed, 904 insertions, 0 deletions
diff --git a/camera.c b/camera.c
new file mode 100644
index 0000000..ca567c8
--- /dev/null
+++ b/camera.c
@@ -0,0 +1,77 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <geometry.h>
+#include <graphics.h>
+
+static int
+max(int a, int b)
+{
+ return a > b ? a : b;
+}
+
+static void
+verifycfg(Camera *c)
+{
+ assert(c->viewport != nil);
+ if(c->ptype == Ppersp)
+ assert(c->fov > 0 && c->fov < 360);
+ assert(c->clip.n > 0 && c->clip.n < c->clip.f);
+}
+
+void
+configcamera(Camera *c, Image *v, double fov, double n, double f, Projection p)
+{
+ c->viewport = v;
+ c->fov = fov;
+ c->clip.n = n;
+ c->clip.f = f;
+ c->ptype = p;
+ reloadcamera(c);
+}
+
+void
+placecamera(Camera *c, Point3 p, Point3 focus, Point3 up)
+{
+ c->p = p;
+ if(focus.w == 0)
+ c->bz = focus;
+ else
+ c->bz = normvec3(subpt3(c->p, focus));
+ c->bx = normvec3(crossvec3(up, c->bz));
+ c->by = crossvec3(c->bz, c->bx);
+}
+
+void
+aimcamera(Camera *c, Point3 focus)
+{
+ placecamera(c, c->p, focus, c->by);
+}
+
+void
+reloadcamera(Camera *c)
+{
+ double a;
+ double l, r, b, t;
+
+ verifycfg(c);
+ switch(c->ptype){
+ case Portho:
+ /*
+ r = Dx(c->viewport->r)/2;
+ t = Dy(c->viewport->r)/2;
+ l = -r;
+ b = -t;
+ */
+ l = t = 0;
+ r = Dx(c->viewport->r);
+ b = Dy(c->viewport->r);
+ orthographic(c->proj, l, r, b, t, c->clip.n, c->clip.f);
+ break;
+ case Ppersp:
+ a = (double)Dx(c->viewport->r)/Dy(c->viewport->r);
+ perspective(c->proj, c->fov, a, c->clip.n, c->clip.f);
+ break;
+ default: sysfatal("unknown projection type");
+ }
+}
diff --git a/doc/libgraphics.ms b/doc/libgraphics.ms
new file mode 100644
index 0000000..87a23a7
--- /dev/null
+++ b/doc/libgraphics.ms
@@ -0,0 +1,34 @@
+.TL
+libgraphics
+.AU
+Rodrigo G. López
+.sp
+rgl@antares-labs.eu
+.AI
+Antares Telecom Laboratories
+Albatera, Alicante
+.FS
+ACHTUNG! this is a
+.B "WORK IN PROGRESS"
+.FE
+.NH 1
+Data Structures
+.NH 2
+Camera
+.P1
+struct Camera {
+ RFrame3; /* VCS */
+ Image *viewport;
+ double fov; /* vertical FOV */
+ struct {
+ double n, f; /* near and far clipping planes */
+ } clip;
+ Projection ptype;
+ Matrix3 proj; /* VCS to viewport xform */
+};
+.P2
+.PP
+A camera is an image capturing entity, analog to the real world device
+we all know, that allows us to see the virtual 3-D world by projecting
+it into a viewport we can attach to a screen or window for real-time
+visualization or write out into a file.
diff --git a/doc/libgraphics.pdf b/doc/libgraphics.pdf
new file mode 100644
index 0000000..0291710
--- /dev/null
+++ b/doc/libgraphics.pdf
Binary files differ
diff --git a/doc/libgraphics.ps b/doc/libgraphics.ps
new file mode 100644
index 0000000..1a566f7
--- /dev/null
+++ b/doc/libgraphics.ps
@@ -0,0 +1,583 @@
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+%
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+%
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+%
+
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+1 pagesetup
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+10 /LucidaSans-Italic f
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+10 /LucidaSansUnicode00 f
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+(Camera) 1375 3110 w
+({) 1830 3110 w
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+(A camera) 970 3546 w
+8 /S1 f
+(__________________) 720 6980 w
+8 /LucidaSansUnicode00 f
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+(WORK) 1493 7080 w
+(IN) 1769 7080 w
+(PROGRESS) 1883 7080 w
+cleartomark
+showpage
+saveobj restore
+%%EndPage: 1 1
+%%Trailer
+done
+%%DocumentFonts: S1 LucidaSansUnicode00 LucidaSans-Demi LucidaSans-Italic LucidaTypewriter
+%%Pages: 1
diff --git a/doc/mkfile b/doc/mkfile
new file mode 100644
index 0000000..3bac031
--- /dev/null
+++ b/doc/mkfile
@@ -0,0 +1,15 @@
+FONTS='.FP lucidasans'
+DOCNAME=libgraphics
+
+all:VQ: $DOCNAME.ps $DOCNAME.pdf
+
+clean:VQ:
+ rm -f $DOCNAME.ps $DOCNAME.pdf
+
+$DOCNAME.ps:V: $DOCNAME.ms
+ {echo $FONTS; cat $prereq}> _$prereq
+ eval `{doctype _$prereq} | lp -dstdout > $target && rm -f _$prereq
+
+$DOCNAME.pdf:V: $DOCNAME.ps
+ cat /sys/doc/docfonts $prereq > _$prereq
+ ps2pdf _$prereq $target && rm -f _$prereq
diff --git a/graphics.h b/graphics.h
new file mode 100644
index 0000000..b9582f3
--- /dev/null
+++ b/graphics.h
@@ -0,0 +1,42 @@
+typedef enum {
+ Portho, /* orthographic */
+ Ppersp /* perspective */
+} Projection;
+
+typedef struct Vertex Vertex;
+typedef struct Camera Camera;
+
+struct Vertex {
+ Point3 p; /* position */
+ Point3 n; /* surface normal */
+};
+
+struct Camera {
+ RFrame3; /* VCS */
+ Image *viewport;
+ double fov; /* vertical FOV */
+ struct {
+ double n, f;
+ } clip;
+ Matrix3 proj; /* VCS to NDC xform */
+ Projection ptype;
+};
+
+/* Camera */
+void configcamera(Camera*, Image*, double, double, double, Projection);
+void placecamera(Camera*, Point3, Point3, Point3);
+void aimcamera(Camera*, Point3);
+void reloadcamera(Camera*);
+
+/* rendering */
+#define FPS2MS(n) (1000/(n))
+#define WORLD2VCS(cp, p) (rframexform3((p), *(cp)))
+#define VCS2NDC(cp, p) (xform3((p), (cp)->proj))
+#define WORLD2NDC(cp, p) (VCS2NDC((cp), WORLD2VCS((cp), (p))))
+int isclipping(Point3);
+Point toviewport(Camera*, Point3);
+Point2 fromviewport(Camera*, Point);
+void perspective(Matrix3, double, double, double, double);
+void orthographic(Matrix3, double, double, double, double, double, double);
+void line3(Camera*, Point3, Point3, int, int, Image*);
+Point string3(Camera*, Point3, Image*, Font*, char*);
diff --git a/mkfile b/mkfile
new file mode 100644
index 0000000..e3defa5
--- /dev/null
+++ b/mkfile
@@ -0,0 +1,12 @@
+</$objtype/mkfile
+
+LIB=libgraphics.a$O
+OFILES=\
+ camera.$O\
+ render.$O\
+
+HFILES=graphics.h ../libgeometry/geometry.h
+
+CFLAGS=$CFLAGS -I. -I../libgeometry
+
+</sys/src/cmd/mklib
diff --git a/readme b/readme
new file mode 100644
index 0000000..d025dce
--- /dev/null
+++ b/readme
@@ -0,0 +1,6 @@
+libgraphics
+
+Libgraphics provides 3D computer graphics through draw(3).
+
+Still in early stages of research, subject to change, drastically, at
+any given time.
diff --git a/render.c b/render.c
new file mode 100644
index 0000000..d8b7088
--- /dev/null
+++ b/render.c
@@ -0,0 +1,135 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+#include <geometry.h>
+#include <graphics.h>
+
+//static Memimage*
+//imagetomemimage(Image *src)
+//{
+// Memimage *dst;
+// uchar *buf;
+// uint buflen;
+//
+// buflen = Dx(src->r)*Dy(src->r);
+// buflen *= (chantodepth(src->chan)+7)/8;
+// buf = malloc(buflen);
+// if(buf == nil)
+// sysfatal("malloc: %r");
+// dst = allocmemimage(src->r, src->chan);
+// if(dst == nil)
+// sysfatal("allocmemimage: %r");
+// if(src->repl){
+// dst->flags |= Frepl;
+// dst->clipr = Rect(-1e6, -1e6, 1e6, 1e6);
+// }
+// unloadimage(src, src->r, buf, buflen);
+// loadmemimage(dst, src->r, buf, buflen);
+// free(buf);
+// return dst;
+//}
+
+static Point2
+flatten(Camera *c, Point3 p)
+{
+ Point2 p2;
+ Matrix S = {
+ Dx(c->viewport->r)/2, 0, 0,
+ 0, Dy(c->viewport->r)/2, 0,
+ 0, 0, 1,
+ }, T = {
+ 1, 0, 1,
+ 0, 1, 1,
+ 0, 0, 1,
+ };
+
+ p2 = Pt2(p.x, p.y, p.w);
+ if(p2.w != 0)
+ p2 = divpt2(p2, p2.w);
+ mulm(S, T);
+ p2 = xform(p2, S);
+ return p2;
+}
+
+/* requires p to be in NDC */
+int
+isclipping(Point3 p)
+{
+ if(p.x > p.w || p.x < -p.w ||
+ p.y > p.w || p.y < -p.w ||
+ p.z > p.w || p.z < 0)
+ return 1;
+ return 0;
+}
+
+Point
+toviewport(Camera *c, Point3 p)
+{
+ Point2 p2;
+ RFrame rf = {
+ c->viewport->r.min.x, c->viewport->r.max.y, 1,
+ 1, 0, 0,
+ 0, -1, 0
+ };
+
+ p2 = invrframexform(flatten(c, p), rf);
+ return Pt(p2.x, p2.y);
+}
+
+Point2
+fromviewport(Camera *c, Point p)
+{
+ RFrame rf = {
+ c->viewport->r.min.x, c->viewport->r.max.y, 1,
+ 1, 0, 0,
+ 0, -1, 0
+ };
+
+ return rframexform(Pt2(p.x,p.y,1), rf);
+}
+
+void
+perspective(Matrix3 m, double fov, double a, double n, double f)
+{
+ double cotan;
+
+ cotan = 1/tan(fov/2*DEG);
+ identity3(m);
+ m[0][0] = cotan/a;
+ m[1][1] = cotan;
+ m[2][2] = -(f+n)/(f-n);
+ m[2][3] = -2*f*n/(f-n);
+ m[3][2] = -1;
+}
+
+void
+orthographic(Matrix3 m, double l, double r, double b, double t, double n, double f)
+{
+ identity3(m);
+ m[0][0] = 2/(r - l);
+ m[1][1] = 2/(t - b);
+ m[2][2] = -2/(f - n);
+ m[0][3] = -(r + l)/(r - l);
+ m[1][3] = -(t + b)/(t - b);
+ m[2][3] = -(f + n)/(f - n);
+}
+
+void
+line3(Camera *c, Point3 p0, Point3 p1, int end0, int end1, Image *src)
+{
+ p0 = WORLD2NDC(c, p0);
+ p1 = WORLD2NDC(c, p1);
+ if(isclipping(p0) || isclipping(p1))
+ return;
+ line(c->viewport, toviewport(c, p0), toviewport(c, p1), end0, end1, 0, src, ZP);
+}
+
+Point
+string3(Camera *c, Point3 p, Image *src, Font *f, char *s)
+{
+ p = WORLD2NDC(c, p);
+ if(isclipping(p))
+ return Pt(-1,-1);
+ return string(c->viewport, toviewport(c, p), src, ZP, f, s);
+}