From b1c758a602262afad23e28ab68d62021a5b1257e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 2 Nov 2016 22:57:10 +0200
Subject: [PATCH] Add the ARB_texture_rg extension

---
 extensions/arb_texture_rg.glext |  2 ++
 source/pixelformat.cpp          | 43 ++++++++++++++++++++++++---------
 source/pixelformat.h            | 14 +++++++----
 3 files changed, 42 insertions(+), 17 deletions(-)
 create mode 100644 extensions/arb_texture_rg.glext

diff --git a/extensions/arb_texture_rg.glext b/extensions/arb_texture_rg.glext
new file mode 100644
index 00000000..567cea12
--- /dev/null
+++ b/extensions/arb_texture_rg.glext
@@ -0,0 +1,2 @@
+extension ARB_texture_rg
+core_version gl 3.0
diff --git a/source/pixelformat.cpp b/source/pixelformat.cpp
index 3fdf6942..ac2b1ea7 100644
--- a/source/pixelformat.cpp
+++ b/source/pixelformat.cpp
@@ -14,6 +14,10 @@ void operator>>(const LexicalConverter &conv, PixelFormat &fmt)
 		fmt = STENCIL_INDEX;
 	else if(conv.get()=="DEPTH_COMPONENT")
 		fmt = DEPTH_COMPONENT;
+	else if(conv.get()=="RED")
+		fmt = RED;
+	else if(conv.get()=="RG")
+		fmt = RG;
 	else if(conv.get()=="RGB")
 		fmt = RGB;
 	else if(conv.get()=="RGBA")
@@ -76,6 +80,12 @@ PixelFormat get_base_pixelformat(PixelFormat pf)
 {
 	switch(pf)
 	{
+	case R8:
+	case R16F:
+	case R32F: return RED;
+	case RG8:
+	case RG16F:
+	case RG32F: return RG;
 	case RGB8:
 	case RGB16F:
 	case RGB32F:
@@ -87,13 +97,9 @@ PixelFormat get_base_pixelformat(PixelFormat pf)
 	case SRGB_ALPHA:
 	case SRGB8_ALPHA8: return RGBA;
 	case LUMINANCE8:
-	case LUMINANCE16F:
-	case LUMINANCE32F:
 	case SLUMINANCE:
 	case SLUMINANCE8: return LUMINANCE;
 	case LUMINANCE_ALPHA8:
-	case LUMINANCE_ALPHA16F:
-	case LUMINANCE_ALPHA32F:
 	case SLUMINANCE_ALPHA:
 	case SLUMINANCE8_ALPHA8: return LUMINANCE_ALPHA;
 	case DEPTH_COMPONENT16:
@@ -107,6 +113,8 @@ PixelFormat get_sized_pixelformat(PixelFormat pf)
 {
 	switch(pf)
 	{
+	case RED: return R8;
+	case RG: return RG8;
 	case RGB: return RGB8;
 	case RGBA: return RGBA8;
 	case SRGB: return SRGB8;
@@ -146,9 +154,11 @@ unsigned get_component_count(PixelFormat pf)
 	{
 	case STENCIL_INDEX:
 	case DEPTH_COMPONENT:
+	case RED:
 	case LUMINANCE:
 	case SLUMINANCE:
 		return 1;
+	case RG:
 	case LUMINANCE_ALPHA:
 	case SLUMINANCE_ALPHA:
 		return 2;
@@ -167,18 +177,18 @@ unsigned get_component_size(PixelFormat pf)
 {
 	switch(pf)
 	{
+	case R16F:
+	case RG16F:
 	case RGB16F:
 	case RGBA16F:
-	case LUMINANCE16F:
-	case LUMINANCE_ALPHA16F:
 	case DEPTH_COMPONENT16:
 		return 2;
 	case DEPTH_COMPONENT24:
 		return 3;
+	case R32F:
+	case RG32F:
 	case RGB32F:
 	case RGBA32F:
-	case LUMINANCE32F:
-	case LUMINANCE_ALPHA32F:
 	case DEPTH_COMPONENT32:
 		return 4;
 	default:
@@ -195,14 +205,23 @@ void require_pixelformat(PixelFormat pf)
 {
 	switch(pf)
 	{
+	case RED:
+	case R8:
+	case RG:
+	case RG8:
+		{ static Require _req(ARB_texture_rg); }
+		break;
+	case R16F:
+	case R32F:
+	case RG16F:
+	case RG32F:
+		{ static Require _req(ARB_texture_rg); }
+		{ static Require _req(ARB_texture_float); }
+		break;
 	case RGB16F:
 	case RGB32F:
 	case RGBA16F:
 	case RGBA32F:
-	case LUMINANCE16F:
-	case LUMINANCE32F:
-	case LUMINANCE_ALPHA16F:
-	case LUMINANCE_ALPHA32F:
 		{ static Require _req(ARB_texture_float); }
 		break;
 	case SRGB:
diff --git a/source/pixelformat.h b/source/pixelformat.h
index b69ad499..17a90d36 100644
--- a/source/pixelformat.h
+++ b/source/pixelformat.h
@@ -6,6 +6,7 @@
 #include "gl.h"
 #include <msp/gl/extensions/arb_depth_texture.h>
 #include <msp/gl/extensions/arb_texture_float.h>
+#include <msp/gl/extensions/arb_texture_rg.h>
 #include <msp/gl/extensions/ext_bgra.h>
 #include <msp/gl/extensions/ext_texture_srgb.h>
 #include <msp/gl/extensions/msp_legacy_features.h>
@@ -21,8 +22,16 @@ enum PixelFormat
 	DEPTH_COMPONENT16 = GL_DEPTH_COMPONENT16,
 	DEPTH_COMPONENT24 = GL_DEPTH_COMPONENT24,
 	DEPTH_COMPONENT32 = GL_DEPTH_COMPONENT32,
+	RED             = GL_RED,
+	RG              = GL_RG,
 	RGB             = GL_RGB,
 	RGBA            = GL_RGBA,
+	R8              = GL_R8,
+	R16F            = GL_R16F,
+	R32F            = GL_R32F,
+	RG8             = GL_RG8,
+	RG16F           = GL_RG16F,
+	RG32F           = GL_RG32F,
 	RGB8            = GL_RGB8,
 	RGB16F          = GL_RGB16F,
 	RGB32F          = GL_RGB32F,
@@ -37,13 +46,8 @@ enum PixelFormat
 	BGRA            = GL_BGRA,
 	LUMINANCE       = GL_LUMINANCE,
 	LUMINANCE8      = GL_LUMINANCE8,
-	// TODO Remove LUMINANCE(_ALPHA) float formats once ARB_texture_rg becomes supported
-	LUMINANCE16F    = GL_LUMINANCE16F_ARB,
-	LUMINANCE32F    = GL_LUMINANCE32F_ARB,
 	LUMINANCE_ALPHA    = GL_LUMINANCE_ALPHA,
 	LUMINANCE8_ALPHA8  = GL_LUMINANCE8_ALPHA8,
-	LUMINANCE_ALPHA16F = GL_LUMINANCE_ALPHA16F_ARB,
-	LUMINANCE_ALPHA32F = GL_LUMINANCE_ALPHA32F_ARB,
 	SLUMINANCE         = GL_SLUMINANCE,
 	SLUMINANCE8        = GL_SLUMINANCE8,
 	SLUMINANCE_ALPHA   = GL_SLUMINANCE_ALPHA,
-- 
2.43.0