From 01c3ca17eeda77ce21f5a00a651bc5cc662c6a43 Mon Sep 17 00:00:00 2001
From: Olivier Prat <olivier@zvork.fr>
Date: Fri, 13 Oct 2017 11:05:27 +0200
Subject: [PATCH] Fixed cube map conversion from equirectangular maps when done
 after HDR conversion

---
 libraries/image/src/image/Image.cpp | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/libraries/image/src/image/Image.cpp b/libraries/image/src/image/Image.cpp
index 59ec4776a6..5959714cd8 100644
--- a/libraries/image/src/image/Image.cpp
+++ b/libraries/image/src/image/Image.cpp
@@ -983,6 +983,9 @@ public:
         glm::vec2 dstCoord;
         glm::ivec2 srcPixel;
         for (int y = 0; y < faceWidth; ++y) {
+            QRgb* destScanLineBegin = reinterpret_cast<QRgb*>( image.scanLine(y) );
+            QRgb* destPixelIterator = destScanLineBegin;
+
             dstCoord.y = 1.0f - (y + 0.5f) * dstInvSize.y; // Fill cube face images from top to bottom
             for (int x = 0; x < faceWidth; ++x) {
                 dstCoord.x = (x + 0.5f) * dstInvSize.x;
@@ -995,13 +998,19 @@ public:
                 srcPixel.y = floor((1.0f - srcCoord.y) * srcFaceHeight);
 
                 if (((uint32)srcPixel.x < (uint32)source.width()) && ((uint32)srcPixel.y < (uint32)source.height())) {
-                    image.setPixel(x, y, source.pixel(QPoint(srcPixel.x, srcPixel.y)));
+                    // We can't directly use the pixel() method because that launches a pixel color conversion to output
+                    // a correct RGBA8 color. But in our case we may have stored HDR values encoded in a RGB30 format which
+                    // are not convertible by Qt. The same goes with the setPixel method, by the way.
+                    const QRgb* sourcePixelIterator = reinterpret_cast<const QRgb*>(source.scanLine(srcPixel.y));
+                    sourcePixelIterator += srcPixel.x;
+                    *destPixelIterator = *sourcePixelIterator;
 
                     // Keep for debug, this is showing the dir as a color
                     //  glm::u8vec4 rgba((xyzDir.x + 1.0)*0.5 * 256, (xyzDir.y + 1.0)*0.5 * 256, (xyzDir.z + 1.0)*0.5 * 256, 256);
                     //  unsigned int val = 0xff000000 | (rgba.r) | (rgba.g << 8) | (rgba.b << 16);
-                    //  image.setPixel(x, y, val);
+                    //  *destPixelIterator = val;
                 }
+                ++destPixelIterator;
             }
         }
         return image;
@@ -1192,6 +1201,10 @@ gpu::TexturePointer TextureUsage::processCubeTextureColorFromImage(const QImage&
     if ((srcImage.width() > 0) && (srcImage.height() > 0)) {
         QImage image = processSourceImage(srcImage, true);
 
+        if (image.format() != QIMAGE_HDR_FORMAT) {
+            image = convertToHDRFormat(image, HDR_FORMAT);
+        }
+
         gpu::Element formatMip;
         gpu::Element formatGPU;
         if (isCubeTexturesCompressionEnabled()) {
@@ -1229,13 +1242,6 @@ gpu::TexturePointer TextureUsage::processCubeTextureColorFromImage(const QImage&
                     faces.push_back(faceImage);
                 }
             }
-
-            if (image.format() != QIMAGE_HDR_FORMAT) {
-                for (auto& face : faces) {
-                    face = convertToHDRFormat(face, HDR_FORMAT);
-                }
-            }
-
         } else {
             qCDebug(imagelogging) << "Failed to find a known cube map layout from this image:" << QString(srcImageName.c_str());
             return nullptr;