From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 19 Dec 2013 21:10:15 +0000 (+0200)
Subject: Automatically determine texture units for effects
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=db2fd517dcd215e9d16345287d413f2a64f5ba03

Automatically determine texture units for effects

At the moment this breaks such effects in fixed-function mode on platforms
that support shader-only texture units.  Will devise a fix later.
---

diff --git a/source/environmentmap.cpp b/source/environmentmap.cpp
index be0bf410..c789fe48 100644
--- a/source/environmentmap.cpp
+++ b/source/environmentmap.cpp
@@ -28,7 +28,6 @@ EnvironmentMap::EnvironmentMap(unsigned s, Renderable &r, Renderable &e):
 	camera.set_aspect(1);
 	camera.set_depth_clip(0.1, 100);
 
-	shdata.uniform("environment", 4);
 }
 
 void EnvironmentMap::setup_frame() const
@@ -72,6 +71,12 @@ void EnvironmentMap::render(Renderer &renderer, const Tag &tag) const
 	if(!enabled_passes.count(tag))
 		return renderer.render(renderable, tag);
 
+	Renderer::Push _push_rend(renderer);
+
+	unsigned unit = renderer.allocate_effect_texunit();
+	shdata.uniform("environment", static_cast<int>(unit));
+	env_tex.bind_to(unit);
+
 	const Matrix &view_matrix = renderer.get_camera()->get_matrix();
 	// XXX The camera should maybe have store its own object matrix
 	float env_mdata[9];
@@ -86,13 +91,10 @@ void EnvironmentMap::render(Renderer &renderer, const Tag &tag) const
 	env_mdata[8] = view_matrix[10];
 	shdata.uniform_matrix3("env_eye_matrix", env_mdata);
 
-	env_tex.bind_to(4);
-
-	Renderer::Push _push_rend(renderer);
 	renderer.add_shader_data(shdata);
 	renderer.render(renderable, tag);
 
-	env_tex.unbind_from(4);
+	env_tex.unbind_from(unit);
 }
 
 } // namespace GL
diff --git a/source/renderer.cpp b/source/renderer.cpp
index b6ece6de..af0d0873 100644
--- a/source/renderer.cpp
+++ b/source/renderer.cpp
@@ -11,6 +11,7 @@
 #include "renderer.h"
 #include "texture.h"
 #include "texturing.h"
+#include "texunit.h"
 #include "vertexarray.h"
 #include "windingtest.h"
 
@@ -74,6 +75,11 @@ void Renderer::set_texturing(const Texturing *t)
 	state->texture = 0;
 }
 
+unsigned Renderer::allocate_effect_texunit()
+{
+	return --state->lowest_effect_texunit;
+}
+
 void Renderer::set_material(const Material *m)
 {
 	state->material = m;
@@ -291,6 +297,7 @@ void Renderer::apply_state()
 Renderer::State::State():
 	texture(0),
 	texturing(0),
+	lowest_effect_texunit(TexUnit::get_n_units()),
 	material(0),
 	lighting(0),
 	shprog(0),
diff --git a/source/renderer.h b/source/renderer.h
index f736447e..1be1a454 100644
--- a/source/renderer.h
+++ b/source/renderer.h
@@ -65,6 +65,7 @@ private:
 	{
 		const Texture *texture;
 		const Texturing *texturing;
+		unsigned lowest_effect_texunit;
 		const Material *material;
 		const Lighting *lighting;
 		Matrix lighting_matrix;
@@ -110,6 +111,7 @@ public:
 
 	void set_texture(const Texture *);
 	void set_texturing(const Texturing *);
+	unsigned allocate_effect_texunit();
 	void set_material(const Material *);
 
 	void set_lighting(const Lighting *);
diff --git a/source/shadowmap.cpp b/source/shadowmap.cpp
index bd87d262..8151a7cf 100644
--- a/source/shadowmap.cpp
+++ b/source/shadowmap.cpp
@@ -33,7 +33,6 @@ ShadowMap::ShadowMap(unsigned s, const Renderable &r, const Light &l):
 	fbo.require_complete();
 
 	set_darkness(0.7);
-	set_texture_unit(3);
 }
 
 void ShadowMap::set_target(const Vector3 &t, float r)
@@ -58,15 +57,6 @@ void ShadowMap::set_depth_bias(float b)
 	depth_bias = b;
 }
 
-void ShadowMap::set_texture_unit(unsigned u)
-{
-	unit = u;
-
-	int i = unit;
-	shdata.uniform("shadow", i);
-	shdata.uniform("shadow_unit", i);
-}
-
 void ShadowMap::setup_frame() const
 {
 	if(rendered)
@@ -131,6 +121,13 @@ void ShadowMap::render(Renderer &renderer, const Tag &tag) const
 	if(!enabled_passes.count(tag))
 		return renderer.render(renderable, tag);
 
+	Renderer::Push _push_rend(renderer);
+
+	unsigned unit = renderer.allocate_effect_texunit();
+	int iunit = unit;
+	shdata.uniform("shadow", iunit);
+	shdata.uniform("shadow_unit", iunit);
+
 	depth_buf.bind_to(unit);
 	TexGen tg_s, tg_t, tg_r;
 	tg_s.set_plane(Vector4(shadow_matrix(0, 0), shadow_matrix(0, 1), shadow_matrix(0, 2), shadow_matrix(0, 3)));
@@ -147,7 +144,6 @@ void ShadowMap::render(Renderer &renderer, const Tag &tag) const
 	else
 		shdata.uniform("shd_eye_matrix", shadow_matrix);
 
-	Renderer::Push _push_rend(renderer);
 	renderer.add_shader_data(shdata);
 	renderer.render(renderable, tag);
 
diff --git a/source/shadowmap.h b/source/shadowmap.h
index 4903afeb..57adf298 100644
--- a/source/shadowmap.h
+++ b/source/shadowmap.h
@@ -28,7 +28,6 @@ private:
 	mutable Matrix light_matrix;
 	mutable Matrix view_matrix;
 	mutable Matrix shadow_matrix;
-	unsigned unit;
 	Texture2D depth_buf;
 	Vector3 target;
 	float radius;
@@ -55,11 +54,6 @@ public:
 	thin objects from casting shadows on nearby sufraces. */
 	void set_depth_bias(float);
 
-	/** Sets the texture unit to bind the shadow map to during the rendering
-	phase.  Provided to shaders through the shadow and shadow_unit uniforms.
-	The default is texture unit 3. */
-	void set_texture_unit(unsigned);
-
 	virtual void setup_frame() const;
 	virtual void finish_frame() const;