From 6dc5c41fe93ed0cb4f9051387b5551182bc5df41 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 29 Mar 2021 01:28:06 +0300
Subject: [PATCH] Make Text more flexible about which texture slot it uses

Different material types have different names for their textures so
using a fixed name here does not cut it anymore.
---
 source/render/text.cpp | 32 ++++++++++++++++++++++++++------
 source/render/text.h   |  9 +++++----
 2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/source/render/text.cpp b/source/render/text.cpp
index b408bbe1..639beac1 100644
--- a/source/render/text.cpp
+++ b/source/render/text.cpp
@@ -1,4 +1,5 @@
 #include "meshbuilder.h"
+#include "program.h"
 #include "text.h"
 #include "texture2d.h"
 
@@ -7,7 +8,7 @@ using namespace std;
 namespace Msp {
 namespace GL {
 
-Text::Text(const Font &f, const Technique *tech):
+Text::Text(const Font &f, const Technique *tech, const string &tex_slot):
 	font(f),
 	mesh((TEXCOORD2, VERTEX2)),
 	horz_align(0.0f),
@@ -16,16 +17,35 @@ Text::Text(const Font &f, const Technique *tech):
 {
 	object.set_mesh(&mesh);
 	if(tech)
-		set_technique(tech);
+		set_technique(tech, tex_slot);
 }
 
-void Text::set_technique(const Technique *tech)
+void Text::set_technique(const Technique *tech, const string &ts)
 {
 	if(tech)
 	{
-		technique = *tech;
-		technique.replace_texture("diffuse_map", font.get_texture());
-		object.set_technique(&technique);
+		const char *tex_slot = ts.c_str();
+		if(!*tex_slot && tech->has_pass(Tag()))
+			if(const Program *shprog = tech->get_pass(Tag()).get_shader_program())
+			{
+				if(shprog->get_uniform_location("font_tex")>=0)
+					tex_slot = "font_tex";
+				else if(shprog->get_uniform_location("color_tex")>=0)
+					tex_slot = "color_tex";
+				else if(shprog->get_uniform_location("diffuse_map")>=0)
+					tex_slot = "diffuse_map";
+				else if(shprog->get_uniform_location("base_color_map")>=0)
+					tex_slot = "base_color_map";
+			}
+
+		if(tex_slot)
+		{
+			technique = *tech;
+			technique.replace_texture(tex_slot, font.get_texture());
+			object.set_technique(&technique);
+		}
+		else
+			object.set_technique(tech);
 	}
 	else
 		object.set_technique(0);
diff --git a/source/render/text.h b/source/render/text.h
index 40c9b850..cbcef957 100644
--- a/source/render/text.h
+++ b/source/render/text.h
@@ -41,13 +41,14 @@ private:
 	float width;
 
 public:
-	Text(const Font &, const Technique * = 0);
+	Text(const Font &, const Technique * = 0, const std::string & = std::string());
 
 	const Mesh *get_mesh() const { return &mesh; }
 
-	/** Sets technique to render with.  It should have a texture slot named
-	"diffuse_map", which will be replaced with the font's texture. */
-	void set_technique(const Technique *);
+	/** Sets technique to render with, replacing the given texture slot with
+	the font texture.  If no texture slot is specified, heuristics are used to
+	choose a suitable one. */
+	void set_technique(const Technique *, const std::string & = std::string());
 
 	const Technique *get_technique() const { return object.get_technique(); }
 
-- 
2.45.2