multipart code examples (#1502)

Signed-off-by: Anton Dukhovnikov <antond@wetafx.co.nz>

src/examples/CMakeLists.txt

@@ -33,6 +33,8 @@ add_executable(OpenEXRExamples
   deepExamples.h
   deepTiledExamples.cpp
   deepTiledExamples.h
+  multipartExamples.cpp
+  multipartExamples.h
 )
 
 target_link_libraries(OpenEXRExamples OpenEXR::OpenEXR)
@@ -66,6 +68,8 @@ install(
     deepExamples.h
     deepTiledExamples.cpp
     deepTiledExamples.h
+    multipartExamples.cpp
+    multipartExamples.h
   DESTINATION
     ${CMAKE_INSTALL_DOCDIR}/examples
   )

src/examples/deepExamples.cpp

@@ -37,6 +37,20 @@ readDeepScanlineFile (
     Array2D<half*>&        dataA,
     Array2D<unsigned int>& sampleCount)
 {
+    //
+    // Read a deep image using class DeepScanLineInputFile.  Try to read one
+    // channel, A, of type HALF, and one channel, Z,
+    // of type FLOAT.  Store the A, and Z pixels in two
+    // separate memory buffers.
+    //
+    //    - open the file
+    //    - allocate memory for the pixels
+    //    - describe the layout of the A, and Z pixel buffers
+    //    - read the sample counts from the file
+    //    - allocate the memory requred to store the samples
+    //    - read the pixels from the file
+    //
+
     DeepScanLineInputFile file (filename);
 
     const Header& header = file.header ();
@@ -106,6 +120,7 @@ readDeepScanlineFile (
 
 unsigned int getPixelSampleCount (int i, int j)
 {
+    // Dummy code creating deep data from a flat image
     return 1;
 }
 
@@ -118,6 +133,7 @@ void getPixelSampleData(
     Array2D<float*>& dataZ,
     Array2D<half*>& dataA)
 {
+    // Dummy code creating deep data from a flat image
     dataZ[i][j][0] = testDataZ[i][j];
     dataA[i][j][0] = testDataA[i][j];
 }
@@ -134,6 +150,17 @@ writeDeepScanlineFile (
     Array2D<unsigned int>& sampleCount)
 
 {
+    //
+    // Write a deep image with only a A (alpha) and a Z (depth) channel,
+    // using class DeepScanLineOutputFile.
+    //
+    //    - create a file header
+    //    - add A and Z channels to the header
+    //    - open the file, and store the header in the file
+    //    - describe the memory layout of the A and Z pixels
+    //    - store the pixels in the file
+    //
+
     int height = dataWindow.max.y - dataWindow.min.y + 1;
     int width  = dataWindow.max.x - dataWindow.min.x + 1;
 
@@ -207,8 +234,8 @@ void deepExamples()
     int h = 600;
 
     Box2i window;
-    window.min.setValue(1, 1);
-    window.max.setValue(w, h);
+    window.min.setValue(0, 0);
+    window.max.setValue(w - 1, h - 1);
 
     Array2D<float *> dataZ;
     dataZ.resizeErase(h, w);
@@ -219,6 +246,7 @@ void deepExamples()
     Array2D<unsigned int> sampleCount;
     sampleCount.resizeErase(h, w);
 
+    // Create an image to be used as a source for deep data
     testDataA.resizeErase(h, w);
     testDataZ.resizeErase(h, w);
     drawImage2(testDataA, testDataZ, w, h);

src/examples/deepTiledExamples.cpp

@@ -49,6 +49,20 @@ readDeepTiledFile (
     Array2D<half*>&        dataA,
     Array2D<unsigned int>& sampleCount)
 {
+    //
+    // Read a deep image using class DeepTiledInputFile.  Try to read one
+    // channel, A, of type HALF, and one channel, Z,
+    // of type FLOAT.  Store the A, and Z pixels in two
+    // separate memory buffers.
+    //
+    //    - open the file
+    //    - allocate memory for the pixels
+    //    - describe the layout of the A, and Z pixel buffers
+    //    - read the sample counts from the file
+    //    - allocate the memory requred to store the samples
+    //    - read the pixels from the file
+    //
+
     DeepTiledInputFile file (filename);
 
     int width  = dataWindow.max.x - dataWindow.min.x + 1;
@@ -151,6 +165,17 @@ writeDeepTiledFile (
     int        tileSizeX,
     int        tileSizeY)
 {
+    //
+    // Write a deep image with only a A (alpha) and a Z (depth) channel,
+    // using class DeepTiledOutputFile.
+    //
+    //    - create a file header
+    //    - add A and Z channels to the header
+    //    - open the file, and store the header in the file
+    //    - describe the memory layout of the A and Z pixels
+    //    - store the pixels in the file
+    //
+
     int height = dataWindow.max.y - dataWindow.min.y + 1;
     int width  = dataWindow.max.x - dataWindow.min.x + 1;
 
@@ -231,8 +256,8 @@ void deepTiledExamples()
     int tileSizeY = 64;
 
     Box2i window;
-    window.min.setValue(1, 1);
-    window.max.setValue(w, h);
+    window.min.setValue(0, 0);
+    window.max.setValue(w - 1, h - 1);
 
     Array2D<float *> dataZ;
     dataZ.resizeErase(h, w);
@@ -243,6 +268,7 @@ void deepTiledExamples()
     Array2D<unsigned int> sampleCount;
     sampleCount.resizeErase(h, w);
 
+    // Create an image to be used as a source for deep data
     testDataA.resizeErase(h, w);
     testDataZ.resizeErase(h, w);
     drawImage2(testDataA, testDataZ, w, h);

src/examples/generalInterfaceExamples.cpp

@@ -44,7 +44,7 @@ writeGZ1 (
     //	- create a file header
     //	- add G and Z channels to the header
     //	- open the file, and store the header in the file
-    //	- describe the memory layout of the G anx Z pixels
+    //	- describe the memory layout of the G and Z pixels
     //	- store the pixels in the file
     //
 

src/examples/main.cpp

@@ -11,6 +11,7 @@
 #include "rgbaInterfaceTiledExamples.h"
 #include "deepExamples.h"
 #include "deepTiledExamples.h"
+#include "multipartExamples.h"
 
 #include <iostream>
 #include <stdexcept>
@@ -25,13 +26,20 @@ main (int argc, char* argv[])
 
         rgbaInterfaceTiledExamples ();
         generalInterfaceTiledExamples ();
-        
-        deepExamples();
-        deepTiledExamples();
+
+        deepExamples ();
+        deepTiledExamples ();
 
         lowLevelIoExamples ();
 
         previewImageExamples ();
+
+        // This example uses the files created by
+        //   generalInterfaceExamples,
+        //   generalInterfaceTiledExamples,
+        //   deepExamples,
+        //   deepTiledExamples
+        multipartExamples ();
     }
     catch (const std::exception& exc)
     {