From 67a0f815e4be5527f5830d0973d87743dd37a7b2 Mon Sep 17 00:00:00 2001
From: AnyOldName3 <krizdjali+github@gmail.com>
Date: Sat, 19 Aug 2017 22:22:20 +0100
Subject: [PATCH] Add support for type-1 (colour-mapped, uncompressed) targa
 images to the osgTGA plugin

---
 src/osgPlugins/tga/ReaderWriterTGA.cpp | 100 ++++++++++++++++++++++---
 1 file changed, 89 insertions(+), 11 deletions(-)

diff --git a/src/osgPlugins/tga/ReaderWriterTGA.cpp b/src/osgPlugins/tga/ReaderWriterTGA.cpp
index 57e37259e..af3b789c7 100644
--- a/src/osgPlugins/tga/ReaderWriterTGA.cpp
+++ b/src/osgPlugins/tga/ReaderWriterTGA.cpp
@@ -174,6 +174,22 @@ static int getInt16(unsigned char *ptr)
     return res | (tmp<<8);
 }
 
+static int getInt24(unsigned char *ptr)
+{
+    int temp1 = ptr[0];
+    int temp2 = ptr[1];
+    int temp3 = ptr[2];
+    return temp1 | (temp2 << 8) | (temp3 << 16);
+}
+
+static int getInt32(unsigned char *ptr)
+{
+    int temp1 = ptr[0];
+    int temp2 = ptr[1];
+    int temp3 = ptr[2];
+    int temp4 = ptr[3];
+    return temp1 | (temp2 << 8) | (temp3 << 16) | (temp4 << 24);
+}
 
 /* */
 /* decode a new rle packet */
@@ -257,6 +273,7 @@ int *numComponents_ret)
     int flags;
     int format;
     unsigned char *colormap;
+    int colormapLen;
     int indexsize;
     int rleIsCompressed;
     int rleRemaining;
@@ -283,10 +300,10 @@ int *numComponents_ret)
     flags = header[17];
 
     /* check for reasonable values in case this is not a tga file */
-    if ((type != 2 && type != 10) ||
+    if ((type != 1 && type != 2 && type != 10) ||
         (width < 0 || width > 4096) ||
         (height < 0 || height > 4096) ||
-        (depth < 2 || depth > 4))
+        (depth < 1 || depth > 4))
     {
         tgaerror = ERR_UNSUPPORTED;
         return NULL;
@@ -298,18 +315,28 @@ int *numComponents_ret)
     colormap = NULL;
     if (header[1] == 1)          /* there is a colormap */
     {
-        int len = getInt16(&header[5]);
+        colormapLen = getInt16(&header[5]);
         indexsize = header[7]>>3;
-        colormap = new unsigned char [len*indexsize];
-        fin.read((char*)colormap,len*indexsize);
-    }
+        colormap = new unsigned char [colormapLen*indexsize];
+        fin.read((char*)colormap,colormapLen*indexsize);
 
-    if (depth == 2)              /* 16 bits */
-    {
-        if (flags & 1) format = 4;
-        else format = 3;
+        if (indexsize == 2)          /* 16 bits */
+        {
+            if (flags & 1) format = 4;
+            else format = 3;
+        }
+        else
+            format = indexsize;
+    }
+    else
+    {
+        if (depth == 2)              /* 16 bits */
+        {
+            if (flags & 1) format = 4;
+            else format = 3;
+        }
+        else format = depth;
     }
-    else format = depth;
 
     /*    SoDebugError::postInfo("simage_tga_load", "TARGA file: %d %d %d %d %d\n",  */
     /*               type, width, height, depth, format); */
@@ -331,6 +358,57 @@ int *numComponents_ret)
 
     switch(type)
     {
+        case 1:                  /* colormap, uncompressed */
+        {
+            unsigned char * formattedMap = new unsigned char[colormapLen * format];
+            for (int i = 0; i < colormapLen; i++)
+            {
+                convert_data(colormap, formattedMap, i, indexsize, format);
+            }
+
+            int x, y;
+            for (y = 0; y < height; y++)
+            {
+                fin.read((char*)linebuf, width*depth);
+                if (fin.gcount() != (std::streamsize) (width*depth))
+                {
+                    tgaerror = ERR_READ;
+                    break;
+                }
+
+                for (x = 0; x < width; x++)
+                {
+                    int index;
+                    switch (depth)
+                    {
+                    case 1:
+                        index = linebuf[x];
+                        break;
+                    case 2:
+                        index = getInt16(linebuf + x * 2);
+                        break;
+                    case 3:
+                        index = getInt24(linebuf + x * 3);
+                        break;
+                    case 4:
+                        index = getInt32(linebuf + x * 4);
+                        break;
+                    default:
+                        tgaerror = ERR_UNSUPPORTED;
+                        break;
+                    }
+
+                    int adjustedX = bLeftToRight ? x : (width - 1) - x;
+                    for (int i = 0; i < format; i++)
+                        (dest + adjustedX * format)[i] = (formattedMap + index * format)[i];
+                }
+                dest += lineoffset;
+            }
+
+            if (formattedMap)
+                delete[] formattedMap;
+        }
+        break;
         case 2:                  /* RGB, uncompressed */
         {
             int x, y;