From 05cc7dce02b656e633c880dcc55acdf370cb25c1 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Wed, 27 Jul 2016 05:24:18 +0300
Subject: [PATCH] -no-srgb option

---
 src/app.cc      |    4 +---
 src/backdrop.cc |   12 +++++++-----
 src/color.cc    |   19 +++++++++++++++++++
 src/color.h     |   12 ++++++++++++
 src/texture.cc  |    9 ++++++---
 5 files changed, 45 insertions(+), 11 deletions(-)
 create mode 100644 src/color.cc
 create mode 100644 src/color.h

diff --git a/src/app.cc b/src/app.cc
index e9e4cbb..81325f6 100644
--- a/src/app.cc
+++ b/src/app.cc
@@ -42,10 +42,8 @@ bool app_init(int argc, char **argv)
 
 	glEnable(GL_CULL_FACE);
 	glEnable(GL_DEPTH_TEST);
-	//glEnable(GL_LIGHTING);
-	glEnable(GL_LIGHT0);
 
-	if(GLEW_ARB_framebuffer_sRGB) {
+	if(opt.srgb && GLEW_ARB_framebuffer_sRGB) {
 		printf("enabling sRGB framebuffer\n");
 		glEnable(GL_FRAMEBUFFER_SRGB);
 	}
diff --git a/src/backdrop.cc b/src/backdrop.cc
index b81a04a..91c709a 100644
--- a/src/backdrop.cc
+++ b/src/backdrop.cc
@@ -6,6 +6,7 @@
 #include "meshgen.h"
 #include "backdrop.h"
 #include "app.h"
+#include "color.h"
 
 static unsigned int sdr_grid;
 static Texture *tex_grid;
@@ -13,14 +14,15 @@ static Texture *tex_grid;
 static Mesh *mesh_skydome;
 static unsigned int sdr_skydome;
 
-static const Vec3 grid_color = Vec3(1.0, 0.07, 1.0);
-static const Vec3 mid_color = Vec3(0.133, 0.006, 0.612);
-static const Vec3 horiz_color = Vec3(0.612, 0.006, 1.0);
-static const Vec3 zenith_color = Vec3(0.029, 0.029, 0.029);
-static const Vec3 fog_color = Vec3(0.01, 0.01, 0.01);
 
 bool init_backdrop()
 {
+	Vec3 grid_color = color(1.0, 0.07, 1.0);
+	Vec3 mid_color = color(0.133, 0.006, 0.612);
+	Vec3 horiz_color = color(0.612, 0.006, 1.0);
+	Vec3 zenith_color = color(0.029, 0.029, 0.029);
+	Vec3 fog_color = color(0.01, 0.01, 0.01);
+
 	if(!(sdr_grid = create_program_load("sdr/grid.v.glsl", "sdr/grid.p.glsl"))) {
 		return false;
 	}
diff --git a/src/color.cc b/src/color.cc
new file mode 100644
index 0000000..ae27f89
--- /dev/null
+++ b/src/color.cc
@@ -0,0 +1,19 @@
+#include "color.h"
+#include "opt.h"
+
+Color color(float r, float g, float b)
+{
+	return opt.srgb ? Color(r, g, b) : linear_to_srgb(Color(r, g, b));
+}
+
+Color linear_to_srgb(const Color &c)
+{
+	const float inv_gamma = 1.0f / 2.2f;
+	return Color(pow(c.x, inv_gamma), pow(c.y, inv_gamma), pow(c.z, inv_gamma));
+}
+
+Color srgb_to_linear(const Color &c)
+{
+	const float gamma = 2.2f;
+	return Color(pow(c.x, gamma), pow(c.y, gamma), pow(c.z, gamma));
+}
diff --git a/src/color.h b/src/color.h
new file mode 100644
index 0000000..2fe4db4
--- /dev/null
+++ b/src/color.h
@@ -0,0 +1,12 @@
+#ifndef COLOR_H_
+#define COLOR_H_
+
+#include "gmath/gmath.h"
+
+typedef Vec3 Color;
+
+Color color(float r, float g, float b);
+Color linear_to_srgb(const Color &c);
+Color srgb_to_linear(const Color &c);
+
+#endif	// COLOR_H_
diff --git a/src/texture.cc b/src/texture.cc
index f332efa..49f3aab 100644
--- a/src/texture.cc
+++ b/src/texture.cc
@@ -3,6 +3,7 @@
 #include "image.h"
 #include "opengl.h"
 #include "imago2.h"
+#include "opt.h"
 
 #if defined(GL_ES_VERSION_2_0) || defined(GL_VERSION_3_0)
 #define USE_GL_GENERATE_MIPMAP
@@ -394,21 +395,23 @@ static int gltype_from_ifmt(unsigned int ifmt)
 
 static int glifmt_from_imgfmt(Image::Format fmt)
 {
+	bool use_srgb = GLEW_EXT_texture_sRGB && opt.srgb;
+
 	switch(fmt) {
 	case Image::FMT_GREY:
-		return GLEW_EXT_texture_sRGB ? GL_SLUMINANCE : GL_LUMINANCE;
+		return use_srgb ? GL_SLUMINANCE : GL_LUMINANCE;
 
 	case Image::FMT_GREY_FLOAT:
 		return GL_LUMINANCE16F;
 
 	case Image::FMT_RGB:
-		return GLEW_EXT_texture_sRGB ? GL_SRGB : GL_RGB;
+		return use_srgb ? GL_SRGB : GL_RGB;
 
 	case Image::FMT_RGB_FLOAT:
 		return GL_RGB16F;
 
 	case Image::FMT_RGBA:
-		return GLEW_EXT_texture_sRGB ? GL_SRGB_ALPHA : GL_RGBA;
+		return use_srgb ? GL_SRGB_ALPHA : GL_RGBA;
 
 	case Image::FMT_RGBA_FLOAT:
 		return GL_RGBA16F;
-- 
1.7.10.4