From 56e8e3de24e7fea36f165b653a8efc8c38145d4c Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Sat, 17 Aug 2024 12:17:46 +0000
Subject: 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.
---
 fb.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 53 insertions(+), 17 deletions(-)

(limited to 'fb.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;
@@ -192,6 +200,36 @@ framebufctl_upscalememdraw(Framebufctl *ctl, Memimage *dst, Point off, Point sca
 	free(blk);
 }
 
+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)
 {
@@ -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;
-- 
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