Revert "Clean bloomblending since it's not used anymore"

This reverts commit 2206f8ad5c.

Conflicts:

	src/graphics/post_processing.cpp

data/shaders/bloomblend.frag

@@ -0,0 +1,14 @@
+uniform sampler2D tex_128;
+uniform sampler2D tex_256;
+uniform sampler2D tex_512;
+
+out vec4 FragColor;
+
+void main()
+{
+    vec2 uv = gl_FragCoord.xy / screen;
+    vec4 col = .125 * texture(tex_128, uv);
+    col += .25 * texture(tex_256, uv);
+    col += .5 * texture(tex_512, uv);
+    FragColor = vec4(col.xyz, 1.);
+}

src/graphics/post_processing.cpp

@@ -742,7 +742,7 @@ FrameBuffer *PostProcessing::render(scene::ICameraSceneNode * const camnode, boo
             renderGaussian6Blur(irr_driver->getFBO(FBO_BLOOM_256), irr_driver->getFBO(FBO_TMP_256), 1., 1.);
             renderGaussian6Blur(irr_driver->getFBO(FBO_BLOOM_128), irr_driver->getFBO(FBO_TMP_128), 1., 1.);
 
-            // Additively blend
+            // Additively blend on top of tmp1
             in_fbo->Bind();
             glEnable(GL_BLEND);
             glBlendFunc(GL_ONE, GL_ONE);

src/graphics/shaders.cpp

@@ -1570,6 +1570,16 @@ namespace FullScreenShader
 
         AssignSamplerNames(Program, 0, "tex");
     }
+
+    BloomBlendShader::BloomBlendShader()
+    {
+        Program = LoadProgram(OBJECT,
+            GL_VERTEX_SHADER, file_manager->getAsset("shaders/screenquad.vert").c_str(),
+            GL_FRAGMENT_SHADER, file_manager->getAsset("shaders/bloomblend.frag").c_str());
+        AssignUniforms();
+
+        AssignSamplerNames(Program, 0, "tex_128", 1, "tex_256", 2, "tex_512");
+    }
 	
 	LensBlendShader::LensBlendShader()
     {

src/graphics/shaders.hpp

@@ -388,6 +388,12 @@ public:
     BloomShader();
 };
 
+class BloomBlendShader : public ShaderHelperSingleton<BloomBlendShader>, public TextureRead<Bilinear_Filtered, Bilinear_Filtered, Bilinear_Filtered>
+{
+public:
+    BloomBlendShader();
+};
+
 class LensBlendShader : public ShaderHelperSingleton<LensBlendShader>, public TextureRead<Bilinear_Filtered, Bilinear_Filtered, Bilinear_Filtered>
 {
 public: