GL3: gamma and intensity via shader

only for 2D rendering, as we don't have 3D yet; also this might need
a more flexible solution later, as some textures are not supposed to
have intensity applied.
According to the old R_Upload32*() and R_LightScaleTexture() the ones
without mipmaps didn't get intensity. Those were it_pic and it_sky (and
the ones in the "scrap", but those were it_pic too)

src/client/refresh/gl3/gl3_image.c

@@ -146,11 +146,6 @@ GL3_Upload32(unsigned *data, int width, int height, qboolean mipmap)
 	scan = ((byte *)data) + 3;
 	samples = gl3_solid_format;
 	comp = gl3_tex_solid_format;
-	//upload_width = width; // TODO: remove, probably
-	//upload_height = height;
-
-	STUB_ONCE("TODO: something with gamma and intensity, somewhere");
-	// R_LightScaleTexture(data, upload_width, upload_height, !mipmap);
 
 	for (i = 0; i < c; i++, scan += 4)
 	{

src/client/refresh/gl3/gl3_main.c

@@ -58,6 +58,8 @@ cvar_t *gl_customheight;
 cvar_t *vid_gamma;
 cvar_t *gl_anisotropic;
 
+cvar_t *intensity;
+
 cvar_t *gl_norefresh;
 cvar_t *gl_nolerp_list;
 cvar_t *gl_nobind;
@@ -104,6 +106,7 @@ GL3_Register(void)
 
 	vid_fullscreen = ri.Cvar_Get("vid_fullscreen", "0", CVAR_ARCHIVE);
 	vid_gamma = ri.Cvar_Get("vid_gamma", "1.0", CVAR_ARCHIVE);
+	intensity = ri.Cvar_Get("intensity", "1.0", CVAR_ARCHIVE);
 
 
 #if 0 // TODO!
@@ -398,10 +401,8 @@ GL3_Init(void)
 		return false;
 	}
 
-	STUB("TODO: Some intensity and gamma stuff that was in R_InitImages()");
-	registration_sequence = 1; // also from R_InitImages()
+	registration_sequence = 1; // from R_InitImages() (everything else from there shouldn't be needed anymore)
 
-	//R_InitImages(); - most of the things in R_InitImages() shouldn't be needed anymore
 	GL3_Mod_Init();
 
 	GL3_InitParticleTexture();
@@ -461,8 +462,9 @@ GL3_SetGL2D(void)
 
 	hmm_mat4 transMatr = HMM_Orthographic(0, vid.width, vid.height, 0, -99999, 99999);
 
+	glUseProgram(gl3state.si2Dcolor.shaderProgram);
+	glUniformMatrix4fv(gl3state.si2Dcolor.uniTransMatrix , 1, GL_FALSE, transMatr.Elements[0]);
 	glUseProgram(gl3state.si2D.shaderProgram);
-
 	glUniformMatrix4fv(gl3state.si2D.uniTransMatrix , 1, GL_FALSE, transMatr.Elements[0]);
 
 	// FIXME: change to GL3 code!
@@ -476,7 +478,6 @@ GL3_SetGL2D(void)
 	glDisable(GL_DEPTH_TEST);
 	glDisable(GL_CULL_FACE);
 	glDisable(GL_BLEND);
-	// glEnable(GL_ALPHA_TEST); TODO: do in shader https://www.khronos.org/opengl/wiki/Transparency_Sorting#Alpha_test
 	// glColor4f(1, 1, 1, 1);
 
 }
@@ -753,6 +754,15 @@ GL3_BeginFrame(float camera_separation)
 	glClearColor(1, 0, 0.5, 0.5);
 
 	GL3_SetGL2D();
+
+	if (vid_gamma->modified || intensity->modified)
+	{
+		vid_gamma->modified = false;
+		intensity->modified = false;
+
+		GL3_SetGammaAndIntensity();
+	}
+
 #if 0
 	gl_state.camera_separation = camera_separation;
 

src/client/refresh/gl3/gl3_shaders.c

@@ -201,16 +201,21 @@ static const char* fragmentSrc2D = MULTILINE_STRING(#version 150\n
 		in vec2 passTexCoord;
 
 		uniform sampler2D tex;
+		uniform float gamma; // this is 1.0/vid_gamma
+		uniform float intensity;
 
 		out vec4 outColor;
 
 		void main()
 		{
-			// TODO: gamma, intensity
 			vec4 texel = texture(tex, passTexCoord);
 			if(texel.a < 0.666)
 				discard;
-			outColor = texel;
+
+			// apply gamma correction and intensity
+			texel.rgb *= intensity;
+			outColor.rgb = pow(texel.rgb, vec3(gamma));
+			outColor.a = texel.a; // I think alpha shouldn't be modified by gamma and intensity
 		}
 );
 
@@ -233,14 +238,16 @@ static const char* vertexSrc2Dcolor = MULTILINE_STRING(#version 150\n
 static const char* fragmentSrc2Dcolor = MULTILINE_STRING(#version 150\n
 		in vec4 passColor;
 
-		uniform sampler2D tex;
+		uniform float gamma; // this is 1.0/vid_gamma
+		uniform float intensity;
 
 		out vec4 outColor;
 
 		void main()
 		{
-			// TODO: gamma, intensity? (not sure we need that here)
-			outColor = passColor;
+			vec3 col = passColor.rgb * intensity;
+			outColor.rgb = pow(col, vec3(gamma));
+			outColor.a = passColor.a;
 		}
 );
 
@@ -324,6 +331,8 @@ qboolean GL3_InitShaders(void)
 		return false;
 	}
 
+	GL3_SetGammaAndIntensity();
+
 	return true;
 }
 
@@ -337,3 +346,27 @@ void GL3_ShutdownShaders(void)
 		glDeleteProgram(gl3state.si2Dcolor.shaderProgram);
 	memset(&gl3state.si2Dcolor, 0, sizeof(gl3ShaderInfo_t));
 }
+
+void GL3_SetGammaAndIntensity(void)
+{
+	float gamma = 1.0f/vid_gamma->value;
+	float intens = intensity->value;
+	int i=0;
+	GLint progs[2] = { gl3state.si2D.shaderProgram, gl3state.si2Dcolor.shaderProgram };
+
+	for(i=0; i<2; ++i)
+	{
+		glUseProgram(progs[i]);
+		GLint uni = glGetUniformLocation(progs[i], "gamma");
+		if(uni != -1)
+		{
+			glUniform1f(uni, gamma);
+		}
+
+		uni = glGetUniformLocation(progs[i], "intensity");
+		if(uni != -1)
+		{
+			glUniform1f(uni, intens);
+		}
+	}
+}

src/client/refresh/gl3/header/local.h

@@ -228,6 +228,7 @@ extern void GL3_SetSky(char *name, float rotate, vec3_t axis);
 // gl3_shaders.c
 extern qboolean GL3_InitShaders(void);
 extern void GL3_ShutdownShaders(void);
+extern void GL3_SetGammaAndIntensity(void);
 
 // ############ Cvars ###########
 
@@ -243,6 +244,7 @@ extern cvar_t *gl_nolerp_list;
 extern cvar_t *gl_nobind;
 
 extern cvar_t *vid_gamma;
+extern cvar_t *intensity;
 extern cvar_t *gl_anisotropic;
 
 extern cvar_t *gl3_debugcontext;