From a435467f81a1d9d429109f3a34988c642bed6035 Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Wed, 4 Mar 2020 21:03:21 +0000
Subject: first steps towards a general rendering architecture.

---
 geometry.h             |  2 +-
 graphics.h             | 11 -----------
 libgraphics/render.c   | 27 +++++++++++++--------------
 libgraphics/triangle.c | 43 -------------------------------------------
 4 files changed, 14 insertions(+), 69 deletions(-)
 delete mode 100644 libgraphics/triangle.c

diff --git a/geometry.h b/geometry.h
index a62d667..0e4f748 100644
--- a/geometry.h
+++ b/geometry.h
@@ -1,4 +1,4 @@
-#define DEG 0.01745329251994330
+#define DEG 0.01745329251994330	/* π/180 */
 
 typedef struct Point2 Point2;
 typedef struct Point3 Point3;
diff --git a/graphics.h b/graphics.h
index be3105d..57aa56e 100644
--- a/graphics.h
+++ b/graphics.h
@@ -4,7 +4,6 @@ typedef enum {
 } Projection;
 
 typedef struct Vertex Vertex;
-typedef struct Triangle Triangle;
 typedef struct Viewport Viewport;
 typedef struct Camera Camera;
 
@@ -14,10 +13,6 @@ struct Vertex {
 	//Image tx;	/* (?) */
 };
 
-struct Triangle {
-	Point p0, p1, p2;
-};
-
 struct Camera {
 	RFrame3;		/* VCS */
 	Image *viewport;
@@ -29,12 +24,6 @@ struct Camera {
 	Projection ptype;
 };
 
-/* Triangle */
-Triangle Trian(int, int, int, int, int, int);
-Triangle Trianpt(Point, Point, Point);
-void triangle(Image *, Triangle, int, Image *, Point);
-void filltriangle(Image *, Triangle, Image *, Point);
-
 /* Camera */
 void perspective(Matrix3, double, double, double, double);
 void orthographic(Matrix3, double, double, double, double, double, double);
diff --git a/libgraphics/render.c b/libgraphics/render.c
index f4e4c0f..ddc0663 100644
--- a/libgraphics/render.c
+++ b/libgraphics/render.c
@@ -4,16 +4,6 @@
 #include "../geometry.h"
 #include "../graphics.h"
 
-/*
- * careful with concurrent rendering.
- * use a lock or embed on each routine.
- */
-static RFrame imgrframe = {
-	0,  0, 1,	/* p */
-	1,  0, 0,	/* bx */
-	0, -1, 0	/* by */
-};
-
 /* requires p to be in NDC */
 int
 isclipping(Point3 p)
@@ -51,17 +41,26 @@ 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
+	};
 
-	imgrframe.p = Pt2(c->viewport->r.min.x, c->viewport->r.max.y, 1);
-	p2 = invrframexform(flatten(c, p), imgrframe);
+	p2 = invrframexform(flatten(c, p), rf);
 	return (Point){p2.x, p2.y};
 }
 
 Point2
 fromviewport(Camera *c, Point p)
 {
-	imgrframe.p = Pt2(c->viewport->r.min.x, c->viewport->r.max.y, 1);
-	return rframexform(Pt2(p.x, p.y, 1), imgrframe);
+	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
diff --git a/libgraphics/triangle.c b/libgraphics/triangle.c
deleted file mode 100644
index b598855..0000000
--- a/libgraphics/triangle.c
+++ /dev/null
@@ -1,43 +0,0 @@
-#include <u.h>
-#include <libc.h>
-#include <draw.h>
-#include "../geometry.h"
-#include "../graphics.h"
-
-Triangle
-Trian(int x0, int y0, int x1, int y1, int x2, int y2)
-{
-	return (Triangle){Pt(x0, y0), Pt(x1, y1), Pt(x2, y2)};
-}
-
-Triangle
-Trianpt(Point p0, Point p1, Point p2)
-{
-	return (Triangle){p0, p1, p2};
-}
-
-void
-triangle(Image *dst, Triangle t, int thick, Image *src, Point sp)
-{
-	Point pl[4];
-
-	pl[0] = t.p0;
-	pl[1] = t.p1;
-	pl[2] = t.p2;
-	pl[3] = pl[0];
-
-	poly(dst, pl, nelem(pl), 0, 0, thick, src, sp);
-}
-
-void
-filltriangle(Image *dst, Triangle t, Image *src, Point sp)
-{
-	Point pl[4];
-
-	pl[0] = t.p0;
-	pl[1] = t.p1;
-	pl[2] = t.p2;
-	pl[3] = pl[0];
-
-	fillpoly(dst, pl, nelem(pl), 0, src, sp);
-}
-- 
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