Packing fix

Unified and fixed packing and unpacking computations.

Change-Id: I1ea2bcf28945a9f105152a6836f11bcb2859750c
Reviewed-on: https://swiftshader-review.googlesource.com/4715
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>

src/OpenGL/common/Image.cpp

diff --git a/src/OpenGL/common/Image.cpp b/src/OpenGL/common/Image.cpp
index ef335b8..81dd0c6 100644
--- a/src/OpenGL/common/Image.cpp
+++ b/src/OpenGL/common/Image.cpp
@@ -1082,6 +1082,12 @@
 		return (rawPitch + alignment - 1) & ~(alignment - 1);
 	}
 
+	size_t ComputePackingOffset(GLenum format, GLenum type, GLsizei width, GLsizei height, GLint alignment, GLint skipImages, GLint skipRows, GLint skipPixels)
+	{
+		GLsizei pitchB = ComputePitch(width, format, type, alignment);
+		return (skipImages * height + skipRows) * pitchB + skipPixels * ComputePixelSize(format, type);
+	}
+
 	inline GLsizei ComputeCompressedPitch(GLsizei width, GLenum format)
 	{
 		return ComputeCompressedSize(width, 1, format);
@@ -1198,9 +1204,10 @@
 
 	void Image::loadImageData(GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const UnpackInfo& unpackInfo, const void *input)
 	{
-		GLsizei inputPitch = ComputePitch((unpackInfo.rowLength == 0) ? width : unpackInfo.rowLength, format, type, unpackInfo.alignment);
+		GLsizei inputWidth = (unpackInfo.rowLength == 0) ? width : unpackInfo.rowLength;
+		GLsizei inputPitch = ComputePitch(inputWidth, format, type, unpackInfo.alignment);
 		GLsizei inputHeight = (unpackInfo.imageHeight == 0) ? height : unpackInfo.imageHeight;
-		input = ((char*)input) + (unpackInfo.skipImages * inputHeight + unpackInfo.skipRows) * inputPitch + unpackInfo.skipPixels;
+		input = ((char*)input) + ComputePackingOffset(format, type, inputWidth, inputHeight, unpackInfo.alignment, unpackInfo.skipImages, unpackInfo.skipRows, unpackInfo.skipPixels);
 		sw::Format selectedInternalFormat = SelectInternalFormat(format, type);
 		if(selectedInternalFormat == sw::FORMAT_NULL)
 		{

src/OpenGL/common/Image.hpp

diff --git a/src/OpenGL/common/Image.hpp b/src/OpenGL/common/Image.hpp
index feabae9..8fa08c1 100644
--- a/src/OpenGL/common/Image.hpp
+++ b/src/OpenGL/common/Image.hpp
@@ -30,6 +30,7 @@
 sw::Format SelectInternalFormat(GLenum format, GLenum type);

 GLsizei ComputePitch(GLsizei width, GLenum format, GLenum type, GLint alignment);

 GLsizei ComputeCompressedSize(GLsizei width, GLsizei height, GLenum format);

+size_t ComputePackingOffset(GLenum format, GLenum type, GLsizei width, GLsizei height, GLint alignment, GLint skipImages, GLint skipRows, GLint skipPixels);

 

 class Image : public sw::Surface, public gl::Object

 {

src/OpenGL/libGLESv2/Context.cpp

diff --git a/src/OpenGL/libGLESv2/Context.cpp b/src/OpenGL/libGLESv2/Context.cpp
index 420370d..430c71a 100644
--- a/src/OpenGL/libGLESv2/Context.cpp
+++ b/src/OpenGL/libGLESv2/Context.cpp
@@ -3319,10 +3319,11 @@
 		return error(GL_INVALID_OPERATION);

 	}

 

-	GLsizei outputPitch = egl::ComputePitch((mState.packRowLength > 0) ? mState.packRowLength : width, format, type, mState.packAlignment);

+	GLsizei outputWidth = (mState.packRowLength > 0) ? mState.packRowLength : width;

+	GLsizei outputPitch = egl::ComputePitch(outputWidth, format, type, mState.packAlignment);

 	GLsizei outputHeight = (mState.packImageHeight == 0) ? height : mState.packImageHeight;

 	pixels = getPixelPackBuffer() ? (unsigned char*)getPixelPackBuffer()->data() + (ptrdiff_t)pixels : (unsigned char*)pixels;

-	pixels = ((char*)pixels) + (mState.packSkipImages * outputHeight + mState.packSkipRows) * outputPitch + mState.packSkipPixels;

+	pixels = ((char*)pixels) + egl::ComputePackingOffset(format, type, outputWidth, outputHeight, mState.packAlignment, mState.packSkipImages, mState.packSkipRows, mState.packSkipPixels);

 

 	// Sized query sanity check

     if(bufSize)

@@ -3341,8 +3342,6 @@
         return error(GL_OUT_OF_MEMORY);

     }

 

-	x += mState.packSkipPixels;

-	y += mState.packSkipRows;

 	sw::Rect rect = {x, y, x + width, y + height};

 	sw::Rect dstRect = { 0, 0, width, height };

 	rect.clip(0, 0, renderTarget->getWidth(), renderTarget->getHeight());