make the fshader return a Color instead of a Memimage. clean things up.

3 files changed, 41 insertions, 30 deletions

diff --git a/graphics.h b/graphics.h
index 85b60ae..94ce2ea 100644
--- a/graphics.h
+++ b/graphics.h
@@ -139,8 +139,6 @@ struct VSparams
 struct FSparams
 {
 	SUparams *su;
-	Memimage *frag;
-	uchar *cbuf;
 	Point p;
 	Vertex v;		/* only for the attributes (varyings) */
 };
@@ -150,6 +148,7 @@ struct SUparams
 {
 	Framebuf *fb;
 	int id;
+	Memimage *frag;
 	Channel *donec;
 
 	/* TODO replace with a Scene */
@@ -158,14 +157,14 @@ struct SUparams
 	uvlong uni_time;
 
 	Point3 (*vshader)(VSparams*);
-	Memimage *(*fshader)(FSparams*);
+	Color (*fshader)(FSparams*);
 };
 
 struct Shader
 {
 	char *name;
-	Point3 (*vshader)(VSparams*);		/* vertex shader */
-	Memimage *(*fshader)(FSparams*);	/* fragment shader */
+	Point3 (*vshader)(VSparams*);	/* vertex shader */
+	Color (*fshader)(FSparams*);	/* fragment shader */
 };
 
 struct Framebuf
diff --git a/render.c b/render.c
index c4e5ab5..ef87792 100644
--- a/render.c
+++ b/render.c
@@ -10,6 +10,17 @@
 
 Rectangle UR = {0,0,1,1};
 
+static ulong
+col2ul(Color c)
+{
+	uchar cbuf[4];
+
+	cbuf[0] = c.a*0xFF;
+	cbuf[1] = c.b*0xFF;
+	cbuf[2] = c.g*0xFF;
+	cbuf[3] = c.r*0xFF;
+	return cbuf[3]<<24 | cbuf[2]<<16 | cbuf[1]<<8 | cbuf[0];
+}
 
 static void
 pixel(Memimage *dst, Point p, Memimage *src)
@@ -281,15 +292,15 @@ orthographic(Matrix3 m, double l, double r, double b, double t, double n, double
 }
 
 static void
-rasterize(SUparams *params, Triangle t, Memimage *frag)
+rasterize(SUparams *params, Triangle t)
 {
 	FSparams fsp;
 	Triangle2 t₂;
 	Rectangle bbox;
 	Point p;
 	Point3 bc;
+	Color c;
 	double z, depth;
-	uchar cbuf[4];
 
 	t₂.p0 = Pt2(t[0].p.x, t[0].p.y, 1);
 	t₂.p1 = Pt2(t[1].p.x, t[1].p.y, 1);
@@ -303,10 +314,7 @@ rasterize(SUparams *params, Triangle t, Memimage *frag)
 	bbox.min.y = max(bbox.min.y, params->fb->r.min.y);
 	bbox.max.x = min(bbox.max.x, params->fb->r.max.x);
 	bbox.max.y = min(bbox.max.y, params->fb->r.max.y);
-	cbuf[0] = 0xFF;
 	fsp.su = params;
-	fsp.frag = frag;
-	fsp.cbuf = cbuf;
 	memset(&fsp.v, 0, sizeof fsp.v);
 
 	for(p.y = bbox.min.y; p.y < bbox.max.y; p.y++)
@@ -325,7 +333,7 @@ rasterize(SUparams *params, Triangle t, Memimage *frag)
 			params->fb->zbuf[p.x + p.y*Dx(params->fb->r)] = depth;
 			unlock(&params->fb->zbuflk);
 
-			/* lerp z⁻¹ and get actual z */
+			/* interpolate z⁻¹ and get actual z */
 			z = t[0].p.w*bc.x + t[1].p.w*bc.y + t[2].p.w*bc.z;
 			z = 1.0/(z < 1e-5? 1e-5: z);
 
@@ -336,13 +344,11 @@ rasterize(SUparams *params, Triangle t, Memimage *frag)
 			bc = mulpt3(bc, z);
 			berpvertex(&fsp.v, &t[0], &t[1], &t[2], bc);
 
-			cbuf[0] = fsp.v.c.a*0xFF;
-			cbuf[1] = fsp.v.c.b*0xFF;
-			cbuf[2] = fsp.v.c.g*0xFF;
-			cbuf[3] = fsp.v.c.r*0xFF;
-
 			fsp.p = p;
-			pixel(params->fb->cb, p, params->fshader(&fsp));
+			c = params->fshader(&fsp);
+			memfillcolor(params->frag, col2ul(c));
+
+			pixel(params->fb->cb, p, params->frag);
 			delvattrs(&fsp.v);
 		}
 }
@@ -352,7 +358,6 @@ shaderunit(void *arg)
 {
 	SUparams *params;
 	VSparams vsp;
-	Memimage *frag;
 	OBJVertex *verts, *tverts, *nverts;	/* geometric, texture and normals vertices */
 	OBJIndexArray *idxtab;
 	OBJElem **ep, **eb, **ee;
@@ -362,7 +367,6 @@ shaderunit(void *arg)
 
 	params = arg;
 	vsp.su = params;
-	frag = rgb(DBlack);
 
 	threadsetname("shader unit #%d", params->id);
 
@@ -455,7 +459,7 @@ shaderunit(void *arg)
 			t[nt][1].p = ndc2viewport(params->fb, t[nt][1].p);
 			t[nt][2].p = ndc2viewport(params->fb, t[nt][2].p);
 
-			rasterize(params, t[nt], frag);
+			rasterize(params, t[nt]);
 
 //skiptri:
 			delvattrs(&t[nt][0]);
@@ -465,9 +469,7 @@ shaderunit(void *arg)
 	}
 
 	free(t);
-	freememimage(frag);
-	sendp(params->donec, nil);
-	free(params);
+	sendp(params->donec, params);
 	threadexits(nil);
 }
 
@@ -488,6 +490,7 @@ shade(Framebuf *fb, Scene *sc, Shader *s)
 		params = emalloc(sizeof *params);
 		params->fb = fb;
 		params->id = i;
+		params->frag = rgb(DBlack);
 		params->donec = donec;
 		params->entity = ent;
 		params->uni_time = time;
@@ -496,7 +499,10 @@ shade(Framebuf *fb, Scene *sc, Shader *s)
 		proccreate(shaderunit, params, mainstacksize);
 	}
 
-	while(i--)
-		recvp(donec);
+	while(i--){
+		params = recvp(donec);
+		freememimage(params->frag);
+		free(params);
+	}
 	chanfree(donec);
 }
diff --git a/texture.c b/texture.c
index 40539db..aadcc84 100644
--- a/texture.c
+++ b/texture.c
@@ -9,7 +9,7 @@
 #include "internal.h"
 
 /*
- * uv-coords belong to the 4th quadrant (v grows bottom-up),
+ * uv-coords belong to the 1st quadrant (v grows bottom-up),
  * hence the need to reverse the v coord.
  */
 static Point
@@ -44,7 +44,7 @@ cbuf2col(uchar b[4])
 }
 
 static Color
-_memreadpixel(Memimage *i, Point sp)
+_memreadcolor(Memimage *i, Point sp)
 {
 	uchar cbuf[4];
 
@@ -66,12 +66,18 @@ _memreadpixel(Memimage *i, Point sp)
 	return cbuf2col(cbuf);
 }
 
+/*
+ * nearest-neighbour sampler
+ */
 Color
 neartexsampler(Memimage *i, Point2 uv)
 {
-	return _memreadpixel(i, uv2tp(uv, i));
+	return _memreadcolor(i, uv2tp(uv, i));
 }
 
+/*
+ * bilinear sampler
+ */
 Color
 bilitexsampler(Memimage *i, Point2 uv)
 {
@@ -92,8 +98,8 @@ bilitexsampler(Memimage *i, Point2 uv)
 		r.min.y--;
 		r.max.y--;
 	}
-	c1 = lerp3(_memreadpixel(i, r.min), _memreadpixel(i, Pt(r.max.x, r.min.y)), 0.5);
-	c2 = lerp3(_memreadpixel(i, Pt(r.min.x, r.max.y)), _memreadpixel(i, r.max), 0.5);
+	c1 = lerp3(_memreadcolor(i, r.min), _memreadcolor(i, Pt(r.max.x, r.min.y)), 0.5);
+	c2 = lerp3(_memreadcolor(i, Pt(r.min.x, r.max.y)), _memreadcolor(i, r.max), 0.5);
 	return lerp3(c1, c2, 0.5);
 }