From 3ec81b814c995b585f19c97cf87fee5b7195382b Mon Sep 17 00:00:00 2001
From: Sergey Sharybin <sergey.vfx@gmail.com>
Date: Thu, 27 Aug 2015 18:50:40 +0200
Subject: Fix T45617: Map UV node produces image artifacts

Basically filtering was happening twice, first time by applying weights of EWA
filter itself and then by applying subpixel offset while reading pixel values.
---
 .../blender/compositor/intern/COM_MemoryBuffer.cpp | 38 +++-------------------
 .../blender/compositor/intern/COM_MemoryBuffer.h   |  2 +-
 .../blender/compositor/intern/COM_SocketReader.h   |  7 ++--
 3 files changed, 8 insertions(+), 39 deletions(-)

(limited to 'source/blender/compositor/intern')

diff --git a/source/blender/compositor/intern/COM_MemoryBuffer.cpp b/source/blender/compositor/intern/COM_MemoryBuffer.cpp
index 2dbf0a6aa46..162e08a95a6 100644
--- a/source/blender/compositor/intern/COM_MemoryBuffer.cpp
+++ b/source/blender/compositor/intern/COM_MemoryBuffer.cpp
@@ -195,45 +195,15 @@ void MemoryBuffer::addPixel(int x, int y, const float color[4])
 	}
 }
 
-typedef struct ReadEWAData {
-	MemoryBuffer *buffer;
-	PixelSampler sampler;
-	float ufac, vfac;
-} ReadEWAData;
-
 static void read_ewa_pixel_sampled(void *userdata, int x, int y, float result[4])
 {
-	ReadEWAData *data = (ReadEWAData *) userdata;
-	switch (data->sampler) {
-		case COM_PS_NEAREST:
-			data->buffer->read(result, x, y);
-			break;
-		case COM_PS_BILINEAR:
-			data->buffer->readBilinear(result,
-			                           (float)x + data->ufac,
-			                           (float)y + data->vfac);
-			break;
-		case COM_PS_BICUBIC:
-			/* TOOD(sergey): no readBicubic method yet */
-			data->buffer->readBilinear(result,
-			                           (float)x + data->ufac,
-			                           (float)y + data->vfac);
-			break;
-		default:
-			zero_v4(result);
-			break;
-	}
+	MemoryBuffer *buffer = (MemoryBuffer *) userdata;
+	buffer->read(result, x, y);
 }
 
-void MemoryBuffer::readEWA(float *result, const float uv[2], const float derivatives[2][2], PixelSampler sampler)
+void MemoryBuffer::readEWA(float *result, const float uv[2], const float derivatives[2][2])
 {
 	BLI_assert(this->m_datatype == COM_DT_COLOR);
-	ReadEWAData data;
-	data.buffer = this;
-	data.sampler = sampler;
-	data.ufac = uv[0] - floorf(uv[0]);
-	data.vfac = uv[1] - floorf(uv[1]);
-
 	int width = this->getWidth(), height = this->getHeight();
 	/* TODO(sergey): Render pipeline uses normalized coordinates and derivatives,
 	 * but compositor uses pixel space. For now let's just divide the values and
@@ -248,6 +218,6 @@ void MemoryBuffer::readEWA(float *result, const float uv[2], const float derivat
 	               true,
 	               uv_normal, du_normal, dv_normal,
 	               read_ewa_pixel_sampled,
-	               &data,
+	               this,
 	               result);
 }
diff --git a/source/blender/compositor/intern/COM_MemoryBuffer.h b/source/blender/compositor/intern/COM_MemoryBuffer.h
index 0b5fc21e69e..de8c14e1a66 100644
--- a/source/blender/compositor/intern/COM_MemoryBuffer.h
+++ b/source/blender/compositor/intern/COM_MemoryBuffer.h
@@ -262,7 +262,7 @@ public:
 		BLI_bilinear_interpolation_fl(this->m_buffer, result, this->m_width, this->m_height, this->m_num_channels, u, v);
 	}
 
-	void readEWA(float *result, const float uv[2], const float derivatives[2][2], PixelSampler sampler);
+	void readEWA(float *result, const float uv[2], const float derivatives[2][2]);
 	
 	/**
 	 * @brief is this MemoryBuffer a temporarily buffer (based on an area, not on a chunk)
diff --git a/source/blender/compositor/intern/COM_SocketReader.h b/source/blender/compositor/intern/COM_SocketReader.h
index 7ba208ebbf6..ab8a3c06ef5 100644
--- a/source/blender/compositor/intern/COM_SocketReader.h
+++ b/source/blender/compositor/intern/COM_SocketReader.h
@@ -93,8 +93,7 @@ protected:
 	 */
 	virtual void executePixelFiltered(float /*output*/[4],
 	                                  float /*x*/, float /*y*/,
-	                                  float /*dx*/[2], float /*dy*/[2],
-	                                  PixelSampler /*sampler*/) {}
+	                                  float /*dx*/[2], float /*dy*/[2]) {}
 
 public:
 	inline void readSampled(float result[4], float x, float y, PixelSampler sampler) {
@@ -103,8 +102,8 @@ public:
 	inline void read(float result[4], int x, int y, void *chunkData) {
 		executePixel(result, x, y, chunkData);
 	}
-	inline void readFiltered(float result[4], float x, float y, float dx[2], float dy[2], PixelSampler sampler) {
-		executePixelFiltered(result, x, y, dx, dy, sampler);
+	inline void readFiltered(float result[4], float x, float y, float dx[2], float dy[2]) {
+		executePixelFiltered(result, x, y, dx, dy);
 	}
 
 	virtual void *initializeTileData(rcti * /*rect*/) { return 0; }
-- 
cgit v1.2.3