From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 28 Mar 2021 11:26:52 +0000 (+0300)
Subject: Add CLAMP_TO_BORDER and border color to Sampler
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=96bbfddc653826ee9848c468c53bca024711a6c3

Add CLAMP_TO_BORDER and border color to Sampler
---

diff --git a/source/core/sampler.cpp b/source/core/sampler.cpp
index 3f853ea0..273f2bb7 100644
--- a/source/core/sampler.cpp
+++ b/source/core/sampler.cpp
@@ -44,6 +44,7 @@ void Sampler::init()
 	wrap_s = REPEAT;
 	wrap_t = REPEAT;
 	wrap_r = REPEAT;
+	border_color = Color(0.0f, 0.0f, 0.0f, 0.0f);
 	compare = false;
 	cmp_func = LEQUAL;
 	dirty_params = 0;
@@ -84,6 +85,8 @@ void Sampler::update_parameter(int mask) const
 		set_parameter_i(GL_TEXTURE_WRAP_T, wrap_t);
 	if(mask&WRAP_R)
 		set_parameter_i(GL_TEXTURE_WRAP_R, wrap_r);
+	if(mask&BORDER_COLOR)
+		set_parameter_fv(GL_TEXTURE_BORDER_COLOR, &border_color.r);
 	if(mask&COMPARE)
 	{
 		set_parameter_i(GL_TEXTURE_COMPARE_MODE, (compare ? GL_COMPARE_R_TO_TEXTURE : GL_NONE));
@@ -112,6 +115,16 @@ void Sampler::set_parameter_f(unsigned param, float value) const
 		glTexParameterf(owner->get_target(), param, value);
 }
 
+void Sampler::set_parameter_fv(unsigned param, const float *value) const
+{
+	if(id)
+		glSamplerParameterfv(id, param, value);
+	else if(ARB_direct_state_access)
+		glTextureParameterfv(owner->get_id(), param, value);
+	else
+		glTexParameterfv(owner->get_target(), param, value);
+}
+
 void Sampler::set_min_filter(TextureFilter f)
 {
 	min_filter = f;
@@ -168,6 +181,12 @@ void Sampler::set_wrap_r(TextureWrap w)
 	update_parameter(WRAP_R);
 }
 
+void Sampler::set_border_color(const Color &c)
+{
+	border_color = c;
+	update_parameter(BORDER_COLOR);
+}
+
 void Sampler::disable_compare()
 {
 	compare = false;
@@ -240,6 +259,7 @@ void Sampler::unload()
 Sampler::Loader::Loader(Sampler &s):
 	DataFile::ObjectLoader<Sampler>(s)
 {
+	add("border_color", &Loader::border_color);
 	add("compare", &Loader::compare);
 	add("filter", &Loader::filter);
 	add("mag_filter", &Loader::mag_filter);
@@ -251,6 +271,11 @@ Sampler::Loader::Loader(Sampler &s):
 	add("wrap_t", &Loader::wrap_t);
 }
 
+void Sampler::Loader::border_color(float r, float g, float b, float a)
+{
+	obj.set_border_color(Color(r, g, b, a));
+}
+
 void Sampler::Loader::compare(Predicate c)
 {
 	obj.set_compare(c);
@@ -327,6 +352,8 @@ void operator>>(const LexicalConverter &c, TextureWrap &tw)
 		tw = REPEAT;
 	else if(c.get()=="CLAMP_TO_EDGE")
 		tw = CLAMP_TO_EDGE;
+	else if(c.get()=="CLAMP_TO_BORDER")
+		tw = CLAMP_TO_BORDER;
 	else if(c.get()=="MIRRORED_REPEAT")
 		tw = MIRRORED_REPEAT;
 	else
diff --git a/source/core/sampler.h b/source/core/sampler.h
index 4208f069..79aea8f8 100644
--- a/source/core/sampler.h
+++ b/source/core/sampler.h
@@ -2,6 +2,7 @@
 #define MSP_GL_SAMPLER_H_
 
 #include <msp/datafile/objectloader.h>
+#include "color.h"
 #include "gl.h"
 #include "predicate.h"
 
@@ -38,6 +39,9 @@ enum TextureWrap
 	/// Extend the texels at the edge of the texture to infinity
 	CLAMP_TO_EDGE = GL_CLAMP_TO_EDGE,
 
+	/// Sampling outside the texture will return border color
+	CLAMP_TO_BORDER = GL_CLAMP_TO_BORDER,
+
 	/// Tile the texture, with every other repetition mirrored
 	MIRRORED_REPEAT = GL_MIRRORED_REPEAT
 };
@@ -69,6 +73,7 @@ public:
 	private:
 		void init();
 
+		void border_color(float, float, float, float);
 		void compare(Predicate);
 		void filter(TextureFilter);
 		void mag_filter(TextureFilter);
@@ -89,7 +94,8 @@ private:
 		WRAP_S = 8,
 		WRAP_T = 16,
 		WRAP_R = 32,
-		COMPARE = 64
+		BORDER_COLOR = 64,
+		COMPARE = 128
 	};
 
 	unsigned id;
@@ -100,6 +106,7 @@ private:
 	TextureWrap wrap_s;
 	TextureWrap wrap_t;
 	TextureWrap wrap_r;
+	Color border_color;
 	bool compare;
 	Predicate cmp_func;
 	mutable int dirty_params;
@@ -113,6 +120,7 @@ private:
 	void update_parameter(int) const;
 	void set_parameter_i(unsigned, int) const;
 	void set_parameter_f(unsigned, float) const;
+	void set_parameter_fv(unsigned, const float *) const;
 
 public:
 	void set_min_filter(TextureFilter);
@@ -135,6 +143,9 @@ public:
 	void set_wrap_t(TextureWrap);
 	void set_wrap_r(TextureWrap);
 
+	void set_border_color(const Color &);
+	const Color &get_border_color() const { return border_color; }
+
 	/** Disables depth comparison. */
 	void disable_compare();