smallpond

commit 8c469723a93d7f64a12c15a2fbc9af0e396253b7
parent 25104c0f73448eb83495f3b8539ad6fecc2153d7
Author: Nihal Jere <nihal@nihaljere.xyz>
Date:   Mon, 26 Sep 2022 12:52:52 -0500

adjust surface size based on content

Diffstat:
M
main.c
 | 
24
++++++++++++++++++++++--
M
smallpond.lua
 | 
94
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----

2 files changed, 112 insertions(+), 6 deletions(-)
diff --git a/main.c b/main.c
@@ -14,6 +14,7 @@
 cairo_t *cr;
 FT_Face face;
 cairo_font_face_t *cface;
+cairo_surface_t *surface;
 
 int
 draw_line(lua_State *L)
@@ -92,10 +93,30 @@ glyph_extents(lua_State *L)
 }
 
 int
+create_surface(lua_State *L)
+{
+	double width = lua_tonumber(L, -2);
+	double height = lua_tonumber(L, -1);
+
+	cairo_destroy(cr);
+	cairo_surface_destroy(surface);
+
+	surface = cairo_pdf_surface_create("out.pdf", width, height);
+	cr = cairo_create(surface);
+
+	cairo_set_font_face(cr, cface);
+	cairo_set_font_size(cr, 32.0);
+
+	return 0;
+}
+
+int
 main(int argc, char *argv[])
 {
 	lua_State *L = luaL_newstate();
 	luaL_openlibs(L);
+	lua_pushcfunction(L, create_surface);
+	lua_setglobal(L, "create_surface");
 	lua_pushcfunction(L, draw_glyph);
 	lua_setglobal(L, "draw_glyph");
 	lua_pushcfunction(L, draw_line);
@@ -125,12 +146,11 @@ main(int argc, char *argv[])
 		return 1;
 	}
 
-	cairo_surface_t *surface = cairo_pdf_surface_create("out.pdf", 648, 864);
+	surface = cairo_image_surface_create (CAIRO_FORMAT_A8, 1, 1);
 	cr = cairo_create(surface);
 
 	cairo_set_font_face(cr, cface);
 	cairo_set_font_size(cr, 32.0);
-
 	if (luaL_dofile(L, "smallpond.lua")) {
 		fprintf(stderr, "lua error: %s\n", lua_tostring(L, -1));
 		return 1;
diff --git a/smallpond.lua b/smallpond.lua
@@ -306,17 +306,103 @@ for i, el in ipairs(staff) do
 	end
 end
 
+-- calculate extents
+local xmin = 0
+local ymin = 0
+local xmax = 0
+local ymax = 0
 for i, d in ipairs(drawables) do
 	if d.kind == "glyph" then
-		draw_glyph(d.glyph, d.x, d.y)
+		-- TODO
+		local w, h = glyph_extents(glyph)
+	elseif d.kind == "line" then
+		if d.x1 < xmin then
+			xmin = d.x1
+		elseif d.x1 > xmax then
+			xmax = d.x1
+		end
+
+		if d.x2 < xmin then
+			xmin = d.x2
+		elseif d.x2 > xmax then
+			xmax = d.x2
+		end
+
+		if d.y1 < ymin then
+			ymin = d.y1
+		elseif d.y1 > ymax then
+			ymax = d.y1
+		end
+
+		if d.y2 < ymin then
+			ymin = d.y2
+		elseif d.y2 > ymax then
+			ymax = d.y2
+		end
+	elseif d.kind == "quad" then
+		if d.x1 < xmin then
+			xmin = d.x1
+		elseif d.x1 > xmax then
+			xmax = d.x1
+		end
+
+		if d.x2 < xmin then
+			xmin = d.x2
+		elseif d.x2 > xmax then
+			xmax = d.x2
+		end
+
+		if d.y1 < ymin then
+			ymin = d.y1
+		elseif d.y1 > ymax then
+			ymax = d.y1
+		end
+
+		if d.y2 < ymin then
+			ymin = d.y2
+		elseif d.y2 > ymax then
+			ymax = d.y2
+		end
+
+		if d.x3 < xmin then
+			xmin = d.x3
+		elseif d.x3 > xmax then
+			xmax = d.x3
+		end
+
+		if d.x4 < xmin then
+			xmin = d.x4
+		elseif d.x4 > xmax then
+			xmax = d.x4
+		end
+
+		if d.y3 < ymin then
+			ymin = d.y3
+		elseif d.y3 > ymax then
+			ymax = d.y3
+		end
+
+		if d.y4 < ymin then
+			ymin = d.y4
+		elseif d.y4 > ymax then
+			ymax = d.y4
+		end
+	end
+end
+
+create_surface(xmax - xmin, ymax - ymin)
+
+for i, d in ipairs(drawables) do
+	if d.kind == "glyph" then
+		draw_glyph(d.glyph, d.x - xmin, d.y - ymin)
 	elseif d.kind == "line" then
-		draw_line(d.t, d.x1, d.y1, d.x2, d.y2)
+		draw_line(d.t, d.x1 - xmin, d.y1 - ymin, d.x2 - xmin, d.y2 - ymin)
 	elseif d.kind == "quad" then
-		draw_quad(d.t, d.x1, d.y1, d.x2, d.y2, d.x3, d.y3, d.x4, d.y4)
+		draw_quad(d.t, d.x1 - xmin, d.y1 - ymin, d.x2 - xmin, d.y2 - ymin, d.x3 - xmin, d.y3 - ymin, d.x4 - xmin, d.y4 - ymin)
 	end
 end
 
 -- draw staff
 for y=0,em*4,em do
-	draw_line(1, xoffset, y + yoffset, x + xoffset, y + yoffset)
+	draw_line(1, xoffset - xmin, y + yoffset - ymin, x + xoffset - xmin, y + yoffset - ymin)
 end