Hook up gl_ssao

source/common/gamecvars.h

@@ -83,6 +83,7 @@ EXTERN_CVAR(Float, vid_gamma)
 EXTERN_CVAR(Float, vid_contrast)
 EXTERN_CVAR(Float, vid_brightness)
 EXTERN_CVAR(Int, gl_multisample)
+EXTERN_CVAR(Int, gl_ssao)
 
 EXTERN_CVAR(Bool, in_joystick)
 EXTERN_CVAR(Int, in_mouse)

source/common/rendering/gl/renderer/gl_renderbuffers.cpp

@@ -128,6 +128,7 @@ void FGLRenderBuffers::Setup(int width, int height, int sceneWidth, int sceneHei
 		I_FatalError("Requested invalid render buffer sizes: screen = %dx%d", width, height);
 
 	int samples = clamp((int)gl_multisample, 0, mMaxSamples);
+	bool needsSceneTextures = (gl_ssao != 0);
 
 	GLint activeTex;
 	GLint textureBinding;
@@ -139,7 +140,7 @@ void FGLRenderBuffers::Setup(int width, int height, int sceneWidth, int sceneHei
 		CreatePipeline(width, height);
 
 	if (width != mWidth || height != mHeight || mSamples != samples)
-		CreateScene(width, height, samples, false);
+		CreateScene(width, height, samples, needsSceneTextures);
 
 	mWidth = width;
 	mHeight = height;

source/common/rendering/gl/system/gl_framebuffer.cpp

@@ -65,6 +65,7 @@ EXTERN_CVAR (Bool, vid_vsync)
 EXTERN_CVAR(Bool, r_drawvoxels)
 EXTERN_CVAR(Int, gl_tonemap)
 EXTERN_CVAR(Bool, gl_texture_usehires)
+EXTERN_CVAR(Int, gl_ssao)
 
 void gl_LoadExtensions();
 void gl_PrintStartupLog();
@@ -431,6 +432,21 @@ void OpenGLFrameBuffer::PostProcessScene(int fixedcm, const std::function<void()
 
 void videoShowFrame(int32_t w)
 {
+    static GLenum buffers[] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
+
+    if (gl_ssao)
+    {
+        glDrawBuffers(1, buffers);
+        OpenGLRenderer::GLRenderer->AmbientOccludeScene(GLInterface.GetMatrix(Matrix_Projection).get()[5]);
+		glViewport(screen->mSceneViewport.left, screen->mSceneViewport.top, screen->mSceneViewport.width, screen->mSceneViewport.height);
+        OpenGLRenderer::GLRenderer->mBuffers->BindSceneFB(true);
+        glDrawBuffers(3, buffers);
+
+		// To do: the translucent part of the scene should be drawn here
+
+		glDrawBuffers(1, buffers);
+    }
+
 	OpenGLRenderer::GLRenderer->mBuffers->BlitSceneToTexture(); // Copy the resulting scene to the current post process texture
 	screen->PostProcessScene(0, []() {
 		GLInterface.Draw2D(&twodpsp); // draws the weapon sprites
@@ -438,7 +454,15 @@ void videoShowFrame(int32_t w)
 	screen->Update();
 	// After finishing the frame, reset everything for the next frame. This needs to be done better.
 	screen->BeginFrame();
+    if (gl_ssao)
+	{
+        OpenGLRenderer::GLRenderer->mBuffers->BindSceneFB(true);
+        glDrawBuffers(3, buffers);
+    }
+    else
+	{
         OpenGLRenderer::GLRenderer->mBuffers->BindSceneFB(false);
+    }
 	twodpsp.Clear();
 	twodgen.Clear();
 }

source/glbackend/glbackend.cpp

@@ -172,7 +172,8 @@ void GLInstance::InitGLState(int fogmode, int multisample)
 	// This is a bad place to call this but without deconstructing the entire render loops in all front ends there is no way to have a well defined spot for this stuff.
 	// Before doing that the backend needs to work in some fashion, so we have to make sure everything is set up when the first render call is performed.
 	screen->BeginFrame();	
-	OpenGLRenderer::GLRenderer->mBuffers->BindSceneFB(false);
+	bool useSSAO = (gl_ssao != 0);
+    OpenGLRenderer::GLRenderer->mBuffers->BindSceneFB(useSSAO);
 }
 
 void GLInstance::Deinit()

wadsrc/static/engine/shaders/glsl/polymost.fp

@@ -48,6 +48,7 @@ in float v_distance;
 in vec4 v_texCoord;
 in vec4 v_detailCoord;
 in float v_fogCoord;
+in vec4 v_eyeCoordPosition;
 
 const float c_basepalScale = 255.0/256.0;
 const float c_basepalOffset = 0.5/256.0;
@@ -59,6 +60,8 @@ const vec4 c_vec4_one = vec4(c_one);
 const float c_wrapThreshold = 0.9;
 
 layout(location=0) out vec4 fragColor;
+layout(location=1) out vec4 fragFog;
+layout(location=2) out vec4 fragNormal;
 
 //===========================================================================
 //
@@ -232,4 +235,9 @@ void main()
 	
 	color.rgb = pow(color.rgb, vec3(u_brightness));
 	fragColor = color;
+	fragFog = vec4(0.0, 0.0, 0.0, 1.0); // Does build have colored fog?
+	vec3 normal = normalize(cross(dFdx(v_eyeCoordPosition.xyz), dFdy(v_eyeCoordPosition.xyz)));
+	normal.x = -normal.x;
+	normal.y = -normal.y;
+	fragNormal = vec4(normal * 0.5 + 0.5, 1.0);
 }

wadsrc/static/engine/shaders/glsl/polymost.vp

@@ -5,6 +5,7 @@ out float v_distance;
 out vec4 v_texCoord;
 out vec4 v_detailCoord;
 out float v_fogCoord;
+out vec4 v_eyeCoordPosition;
 
 uniform float u_usePalette;
 uniform mat4 u_rotMatrix;
@@ -25,6 +26,7 @@ void main()
 {
    vec4 vertex = u_rotMatrix * i_vertPos;
    vec4 eyeCoordPosition = u_modelMatrix * vertex;
+   v_eyeCoordPosition = eyeCoordPosition;
    gl_Position = u_projectionMatrix * eyeCoordPosition;
 
    eyeCoordPosition.xyz /= eyeCoordPosition.w;