protected override void DrawCore(RenderDrawContext context)
{
// Note: if no previous texture yet, skip rendering
if (previousTexture != null)
{
SetInput(3, previousTexture);
base.DrawCore(context);
}
// Copy current state for next frame
{
var input = GetInput(0);
// Do we need to reallocate?
if (previousTexture == null || previousTexture.Width != input.Width || previousTexture.Height != input.Height)
{
if (previousTexture != null)
{
context.GraphicsContext.Allocator.ReleaseReference(previousTexture);
}
// Note: no need for multisample
var description = input.Description;
description.MultisampleCount = MultisampleCount.None;
previousTexture = context.GraphicsContext.Allocator.GetTemporaryTexture(description);
}
textureScaler.SetInput(input);
textureScaler.SetOutput(previousTexture);
textureScaler.Draw(context);
}
}
protected override void DrawCore(RenderDrawContext context)
{
var originalColorBuffer = GetSafeInput(0);
var originalDepthBuffer = GetSafeInput(1);
var outputTexture = GetSafeOutput(0);
if (configurationDirty)
{
SetupTechnique();
}
// Preparation phase: create different downscaled versions of the original image, later needed by the bokeh blur shaders.
// TODO use ImageMultiScaler instead?
downscaledSources.Clear();
// First we linearize the depth and compute the CoC map based on the user lens configuration.
// Render target will contain "CoC"(16 bits) "Linear depth"(16bits).
var cocLinearDepthTexture = GetScopedRenderTarget(originalColorBuffer.Description, 1f, PixelFormat.R16G16_Float);
var renderView = context.RenderContext.RenderView;
var farPlane = renderView.FarClipPlane;
var depthAreas = DOFAreas;
if (AutoFocus)
{
// TODO replace this by physical camera parameters (aperture, focus distance...)
var diffToTarget = (autoFocusDistanceTarget - autoFocusDistanceCurrent);
var maxAmplitude = farPlane * 0.2f;
diffToTarget = MathUtil.Clamp(diffToTarget, -maxAmplitude, maxAmplitude);
autoFocusDistanceCurrent = autoFocusDistanceCurrent + 0.1f * diffToTarget;
if (autoFocusDistanceCurrent < renderView.NearClipPlane * 2.0f)
{
autoFocusDistanceCurrent = renderView.NearClipPlane * 2.0f;
}
depthAreas = new Vector4(renderView.NearClipPlane, autoFocusDistanceCurrent, autoFocusDistanceCurrent, autoFocusDistanceCurrent + farPlane * 0.5f);
}
coclinearDepthMapEffect.SetInput(0, originalDepthBuffer);
coclinearDepthMapEffect.SetOutput(cocLinearDepthTexture);
coclinearDepthMapEffect.Parameters.Set(CircleOfConfusionKeys.depthAreas, ref depthAreas);
coclinearDepthMapEffect.Parameters.Set(CameraKeys.ZProjection, CameraKeys.ZProjectionACalculate(renderView.NearClipPlane, renderView.FarClipPlane));
coclinearDepthMapEffect.Draw(context, "CoC_LinearDepth");
if (AutoFocus)
{
// Reads the center depth of the previous frame and use it as a new target
// TODO single pixel is really small, average some disk area instead?
pointDepthShader.Parameters.Set(PointDepthKeys.Coordinate, new Vector2(0.5f, 0.5f));
pointDepthShader.SetInput(cocLinearDepthTexture);
pointDepthShader.SetOutput(depthCenter1x1);
pointDepthShader.Draw(context, "Center Depth");
depthReadBack.SetInput(depthCenter1x1);
depthReadBack.Draw(context, "Center_Depth_Readback");
var centerDepth = depthReadBack.Result[0];
autoFocusDistanceTarget = centerDepth;
}
// Find the smallest downscale we should go down to.
var maxDownscale = 0;
foreach (var cocLevel in cocLevels)
{
if (cocLevel.DownscaleFactor > maxDownscale)
{
maxDownscale = cocLevel.DownscaleFactor;
}
}
// Create a series of downscale, with anti-bleeding treatment
for (int i = 0; i <= maxDownscale; i++)
{
var downSizedTexture = originalColorBuffer;
if (i > 0)
{
downSizedTexture = GetScopedRenderTarget(originalColorBuffer.Description, 1f / (float)Math.Pow(2f, i), originalColorBuffer.Description.Format);
textureScaler.SetInput(0, downscaledSources[i - 1]);
textureScaler.SetOutput(downSizedTexture);
textureScaler.Draw(context, "DownScale_Factor{0}", i);
}
downscaledSources[i] = downSizedTexture;
}
// We create a blurred version of the CoC map.
// This is useful to avoid silhouettes appearing when the CoC changes abruptly.
var blurredCoCTexture = NewScopedRenderTarget2D(cocLinearDepthTexture.Description);
cocMapBlur.Radius = 6f / 720f * cocLinearDepthTexture.Description.Height; // 6 pixels at 720p
cocMapBlur.SetInput(0, cocLinearDepthTexture);
cocMapBlur.SetOutput(blurredCoCTexture);
cocMapBlur.Draw(context, "CoC_BlurredMap");
// Creates all the levels with different CoC strengths.
// (Skips level with CoC 0 which is always the original buffer.)
combineLevelsEffect.Parameters.Set(CombineLevelsFromCoCKeys.LevelCount, cocLevels.Count);
combineLevelsEffect.SetInput(0, cocLinearDepthTexture);
combineLevelsEffect.SetInput(1, blurredCoCTexture);
combineLevelsEffect.SetInput(2, originalColorBuffer);
combineLevelsFrontEffect.Parameters.Set(CombineLevelsFromCoCKeys.LevelCount, cocLevels.Count);
combineLevelsFrontEffect.SetInput(0, cocLinearDepthTexture);
combineLevelsFrontEffect.SetInput(1, blurredCoCTexture);
combineLevelsFrontEffect.SetInput(2, originalColorBuffer);
float previousCoC = 0f;
for (int i = 1; i < cocLevels.Count; i++)
{
// We render a blurred version of the original scene into a downscaled render target.
// Blur strength depends on the current level CoC value.
var levelConfig = cocLevels[i];
var textureToBlur = downscaledSources[levelConfig.DownscaleFactor];
float downscaleFactor = 1f / (float)(Math.Pow(2f, levelConfig.DownscaleFactor));
var blurOutput = GetScopedRenderTarget(originalColorBuffer.Description, downscaleFactor, originalColorBuffer.Description.Format);
var blurOutputFront = NewScopedRenderTarget2D(blurOutput.Description);
float blurRadius = (MaxBokehSize * BokehSizeFactor) * levelConfig.CoCValue * downscaleFactor * originalColorBuffer.Width;
if (blurRadius < 1f)
{
blurRadius = 1f;
}
//---------------------------------
// Far out-of-focus
//---------------------------------
// Pre-process the layer for the current CoC
// This removes areas which might wrongly bleed into our image when blurring.
var alphaTextureToBlur = NewScopedRenderTarget2D(textureToBlur.Description);
thresholdAlphaCoC.Parameters.Set(ThresholdAlphaCoCKeys.CoCReference, previousCoC);
thresholdAlphaCoC.Parameters.Set(ThresholdAlphaCoCKeys.CoCCurrent, levelConfig.CoCValue);
thresholdAlphaCoC.SetInput(0, textureToBlur);
thresholdAlphaCoC.SetInput(1, cocLinearDepthTexture);
thresholdAlphaCoC.SetOutput(alphaTextureToBlur);
thresholdAlphaCoC.Draw(context, "Alphaize_Far_{0}", i);
textureToBlur = alphaTextureToBlur;
// TODO Quality up: make the opaque areas "bleed" into the areas we just made transparent
// Apply the bokeh blur effect
BokehBlur levelBlur = levelConfig.BlurEffect;
levelBlur.CoCStrength = levelConfig.CoCValue;
levelBlur.Radius = blurRadius; // This doesn't generate garbage if the radius value doesn't change.
levelBlur.SetInput(0, textureToBlur);
levelBlur.SetOutput(blurOutput);
levelBlur.Draw(context, "CoC_LoD_Layer_Far_{0}", i);
combineLevelsEffect.SetInput(i + 2, blurOutput);
//---------------------------------
// Near out-of-focus
//---------------------------------
// Negates CoC values and makes background objects transparent
thresholdAlphaCoCFront.Parameters.Set(ThresholdAlphaCoCFrontKeys.CoCReference, previousCoC);
thresholdAlphaCoCFront.Parameters.Set(ThresholdAlphaCoCFrontKeys.CoCCurrent, levelConfig.CoCValue);
thresholdAlphaCoCFront.SetInput(0, downscaledSources[levelConfig.DownscaleFactor]);
thresholdAlphaCoCFront.SetInput(1, cocLinearDepthTexture);
thresholdAlphaCoCFront.SetOutput(alphaTextureToBlur);
thresholdAlphaCoCFront.Draw(context, "Alphaize_Near_{0}", i);
textureToBlur = alphaTextureToBlur;
// Apply the bokeh blur effect
levelBlur.SetInput(0, textureToBlur);
levelBlur.SetOutput(blurOutputFront);
levelBlur.Draw(context, "CoC_LoD_Layer_Near_{0}", i);
combineLevelsFrontEffect.SetInput(i + 2, blurOutputFront);
previousCoC = levelConfig.CoCValue;
}
// Far out-of-focus: each pixel, depending on its CoC, interpolates its color from
// the original color buffer and blurred buffer(s).
combineLevelsEffect.Parameters.Set(CombineLevelsFromCoCShaderKeys.CoCLevelValues, combineShaderCocLevelValues);
combineLevelsEffect.SetOutput(outputTexture);
combineLevelsEffect.Draw(context, "CoCLevelCombineInterpolation");
// Finally add front out-of-focus objects on the top of the scene
// TODO Quality up: instead of merging all the layers for each pixel, merge only
// the relevant layer(s) closest to the pixel CoC.
combineLevelsFrontEffect.SetOutput(outputTexture);
combineLevelsFrontEffect.Draw(context, "CoCLevelCombineInterpolationFront");
// Release any reference
downscaledSources.Clear();
}