unify drawing routines and add clipped fb drawing support.

now changing the viewport offset will correctly show the
portion of the framebuffer that's visible, including
support for upscaled views.

4 files changed, 70 insertions, 33 deletions

diff --git a/camera.c b/camera.c
index e67601f..ccd1f57 100644
--- a/camera.c
+++ b/camera.c
@@ -114,6 +114,10 @@ Cam(Rectangle vr, Renderer *r, Projection p, double fov, double n, double f)
 
 	c = newcamera();
 	c->view = mkviewport(vr);
+	if(c->view == nil){
+		werrstr("mkviewport: %r");
+		return nil;
+	}
 	c->rctl = r;
 	configcamera(c, p, fov, n, f);
 	return c;
diff --git a/fb.c b/fb.c
index 4b1f82e..2c1d494 100644
--- a/fb.c
+++ b/fb.c
@@ -93,18 +93,7 @@ scale3x_filter(ulong *dst, Framebuf *fb, Point sp)
 //}
 
 static void
-framebufctl_draw(Framebufctl *ctl, Image *dst, Point off)
-{
-	Framebuf *fb;
-
-	qlock(ctl);
-	fb = ctl->getfb(ctl);
-	loadimage(dst, rectaddpt(fb->r, addpt(dst->r.min, off)), (uchar*)fb->cb, Dx(fb->r)*Dy(fb->r)*4);
-	qunlock(ctl);
-}
-
-static void
-framebufctl_upscaledraw(Framebufctl *ctl, Image *dst, Point off, Point scale)
+upscaledraw(Framebufctl *ctl, Image *dst, Point off, Point scale)
 {
 	void (*filter)(ulong*, Framebuf*, Point);
 	Framebuf *fb;
@@ -143,18 +132,37 @@ framebufctl_upscaledraw(Framebufctl *ctl, Image *dst, Point off, Point scale)
 }
 
 static void
-framebufctl_memdraw(Framebufctl *ctl, Memimage *dst, Point off)
+framebufctl_draw(Framebufctl *ctl, Image *dst, Point off, Point scale)
 {
 	Framebuf *fb;
+	Rectangle sr, dr;
+	ulong *cb;
+	int y;
+
+	if(scale.x > 1 || scale.y > 1){
+		upscaledraw(ctl, dst, off, scale);
+		return;
+	}
 
 	qlock(ctl);
 	fb = ctl->getfb(ctl);
-	loadmemimage(dst, rectaddpt(fb->r, addpt(dst->r.min, off)), (uchar*)fb->cb, Dx(fb->r)*Dy(fb->r)*4);
+	sr = rectaddpt(fb->r, off);
+	dr = rectsubpt(dst->r, dst->r.min);
+	if(rectinrect(sr, dr))
+		loadimage(dst, rectaddpt(sr, dst->r.min), (uchar*)fb->cb, Dx(fb->r)*Dy(fb->r)*4);
+	else if(rectclip(&sr, dr)){
+		cb = emalloc(Dx(sr)*Dy(sr)*4);
+		/* TODO there must be a cleaner way to do this */
+		for(y = sr.min.y; y < sr.max.y; y++)
+			memmove(&cb[(y - sr.min.y)*Dx(sr)], &fb->cb[max(y - off.y,0)*Dx(fb->r) + max(-off.x,0)], Dx(sr)*4);
+		loadimage(dst, rectaddpt(sr, dst->r.min), (uchar*)cb, Dx(sr)*Dy(sr)*4);
+		free(cb);
+	}
 	qunlock(ctl);
 }
 
 static void
-framebufctl_upscalememdraw(Framebufctl *ctl, Memimage *dst, Point off, Point scale)
+upscalememdraw(Framebufctl *ctl, Memimage *dst, Point off, Point scale)
 {
 	void (*filter)(ulong*, Framebuf*, Point);
 	Framebuf *fb;
@@ -193,6 +201,36 @@ framebufctl_upscalememdraw(Framebufctl *ctl, Memimage *dst, Point off, Point sca
 }
 
 static void
+framebufctl_memdraw(Framebufctl *ctl, Memimage *dst, Point off, Point scale)
+{
+	Framebuf *fb;
+	Rectangle sr, dr;
+	ulong *cb;
+	int y;
+
+	if(scale.x > 1 || scale.y > 1){
+		upscalememdraw(ctl, dst, off, scale);
+		return;
+	}
+
+	qlock(ctl);
+	fb = ctl->getfb(ctl);
+	sr = rectaddpt(fb->r, off);
+	dr = rectsubpt(dst->r, dst->r.min);
+	if(rectinrect(sr, dr))
+		loadmemimage(dst, rectaddpt(sr, dst->r.min), (uchar*)fb->cb, Dx(fb->r)*Dy(fb->r)*4);
+	else if(rectclip(&sr, dr)){
+		cb = emalloc(Dx(sr)*Dy(sr)*4);
+		/* TODO there must be a cleaner way to do this */
+		for(y = sr.min.y; y < sr.max.y; y++)
+			memmove(&cb[(y - sr.min.y)*Dx(sr)], &fb->cb[max(y - off.y,0)*Dx(fb->r) + max(-off.x,0)], Dx(sr)*4);
+		loadmemimage(dst, rectaddpt(sr, dst->r.min), (uchar*)cb, Dx(sr)*Dy(sr)*4);
+		free(cb);
+	}
+	qunlock(ctl);
+}
+
+static void
 framebufctl_drawnormals(Framebufctl *ctl, Image *dst)
 {
 	Framebuf *fb;
@@ -280,9 +318,7 @@ mkfbctl(Rectangle r)
 	fc->fb[0] = mkfb(r);
 	fc->fb[1] = mkfb(r);
 	fc->draw = framebufctl_draw;
-	fc->upscaledraw = framebufctl_upscaledraw;
 	fc->memdraw = framebufctl_memdraw;
-	fc->upscalememdraw = framebufctl_upscalememdraw;
 	fc->drawnormals = framebufctl_drawnormals;
 	fc->swap = framebufctl_swap;
 	fc->reset = framebufctl_reset;
diff --git a/graphics.h b/graphics.h
index 6362075..1360210 100644
--- a/graphics.h
+++ b/graphics.h
@@ -287,10 +287,8 @@ struct Framebufctl
 	uint idx;		/* front buffer index */
 	uint upfilter;		/* upscaling filter */
 
-	void (*draw)(Framebufctl*, Image*, Point);
-	void (*upscaledraw)(Framebufctl*, Image*, Point, Point);
-	void (*memdraw)(Framebufctl*, Memimage*, Point);
-	void (*upscalememdraw)(Framebufctl*, Memimage*, Point, Point);
+	void (*draw)(Framebufctl*, Image*, Point, Point);
+	void (*memdraw)(Framebufctl*, Memimage*, Point, Point);
 	void (*drawnormals)(Framebufctl*, Image*);
 	void (*swap)(Framebufctl*);
 	void (*reset)(Framebufctl*, ulong);
diff --git a/viewport.c b/viewport.c
index 9e41e53..5214e53 100644
--- a/viewport.c
+++ b/viewport.c
@@ -15,13 +15,10 @@ viewport_draw(Viewport *v, Image *dst)
 
 	off = Pt(v->p.x, v->p.y);
 	/* no downsampling support yet */
-	scale.x = max(min(v->bx.x, Dx(dst->r)/Dx(v->r)), 1);
-	scale.y = max(min(v->by.y, Dy(dst->r)/Dy(v->r)), 1);
+	scale.x = max(v->bx.x, 1);
+	scale.y = max(v->by.y, 1);
 
-	if(scale.x > 1 || scale.y > 1)
-		v->fbctl->upscaledraw(v->fbctl, dst, off, scale);
-	else
-		v->fbctl->draw(v->fbctl, dst, off);
+	v->fbctl->draw(v->fbctl, dst, off, scale);
 }
 
 static void
@@ -31,13 +28,10 @@ viewport_memdraw(Viewport *v, Memimage *dst)
 
 	off = Pt(v->p.x, v->p.y);
 	/* no downsampling support yet */
-	scale.x = max(min(v->bx.x, Dx(dst->r)/Dx(v->r)), 1);
-	scale.y = max(min(v->by.y, Dy(dst->r)/Dy(v->r)), 1);
+	scale.x = max(v->bx.x, 1);
+	scale.y = max(v->by.y, 1);
 
-	if(scale.x > 1 || scale.y > 1)
-		v->fbctl->upscalememdraw(v->fbctl, dst, off, scale);
-	else
-		v->fbctl->memdraw(v->fbctl, dst, off);
+	v->fbctl->memdraw(v->fbctl, dst, off, scale);
 }
 
 static void
@@ -78,6 +72,11 @@ mkviewport(Rectangle r)
 {
 	Viewport *v;
 
+	if(badrect(r)){
+		werrstr("bad viewport rectangle");
+		return nil;
+	}
+
 	v = emalloc(sizeof *v);
 	v->p = Pt2(0,0,1);
 	v->bx = Vec2(1,0);