From 839b8d432e571a67e0847c1d901e43e3ae254381 Mon Sep 17 00:00:00 2001
From: Brad Davis <bdavis@saintandreas.org>
Date: Mon, 8 Feb 2016 23:54:10 -0800
Subject: [PATCH] Don't burn CPU cycles calculating an average color we don't
 use

---
 libraries/model/src/model/TextureMap.cpp | 81 +++++++-----------------
 1 file changed, 24 insertions(+), 57 deletions(-)

diff --git a/libraries/model/src/model/TextureMap.cpp b/libraries/model/src/model/TextureMap.cpp
index a86c7cdbec..e59d9716e6 100755
--- a/libraries/model/src/model/TextureMap.cpp
+++ b/libraries/model/src/model/TextureMap.cpp
@@ -50,88 +50,55 @@ void TextureMap::setLightmapOffsetScale(float offset, float scale) {
 }
 
 
-
-
+// FIXME why is this in the model library?  Move to GPU or GPU_GL
 gpu::Texture* TextureUsage::create2DTextureFromImage(const QImage& srcImage, const std::string& srcImageName) {
     QImage image = srcImage;
- 
-    int imageArea = image.width() * image.height();
-    
-    int opaquePixels = 0;
-    int translucentPixels = 0;
-    //bool isTransparent = false;
-    int redTotal = 0, greenTotal = 0, blueTotal = 0, alphaTotal = 0;
-    const int EIGHT_BIT_MAXIMUM = 255;
-    QColor averageColor(EIGHT_BIT_MAXIMUM, EIGHT_BIT_MAXIMUM, EIGHT_BIT_MAXIMUM);
-    
-    if (!image.hasAlphaChannel()) {
-        if (image.format() != QImage::Format_RGB888) {
-            image = image.convertToFormat(QImage::Format_RGB888);
-        }
-        // int redTotal = 0, greenTotal = 0, blueTotal = 0;
-        for (int y = 0; y < image.height(); y++) {
-            for (int x = 0; x < image.width(); x++) {
-                QRgb rgb = image.pixel(x, y);
-                redTotal += qRed(rgb);
-                greenTotal += qGreen(rgb);
-                blueTotal += qBlue(rgb);
-            }
-        }
-        if (imageArea > 0) {
-            averageColor.setRgb(redTotal / imageArea, greenTotal / imageArea, blueTotal / imageArea);
-        }
-    } else {
+    if (image.hasAlphaChannel()) {
         if (image.format() != QImage::Format_ARGB32) {
             image = image.convertToFormat(QImage::Format_ARGB32);
         }
         
-        // check for translucency/false transparency
-        // int opaquePixels = 0;
-        // int translucentPixels = 0;
-        // int redTotal = 0, greenTotal = 0, blueTotal = 0, alphaTotal = 0;
-        for (int y = 0; y < image.height(); y++) {
-            for (int x = 0; x < image.width(); x++) {
-                QRgb rgb = image.pixel(x, y);
-                redTotal += qRed(rgb);
-                greenTotal += qGreen(rgb);
-                blueTotal += qBlue(rgb);
-                int alpha = qAlpha(rgb);
-                alphaTotal += alpha;
-                if (alpha == EIGHT_BIT_MAXIMUM) {
-                    opaquePixels++;
-                } else if (alpha != 0) {
-                    translucentPixels++;
+        // Actual alpha channel?
+        bool transparent { false };
+        for (int y = 0; y < image.height(); ++y) {
+            const QRgb* data = reinterpret_cast<const QRgb*>(image.constScanLine(y));
+            for (int x = 0; x < image.width(); ++x) {
+                auto alpha = qAlpha(data[x]);
+                if (alpha != 255) {
+                    transparent = true;
+                    break;
                 }
             }
         }
-        if (opaquePixels == imageArea) {
+
+        // or bullshit alpha channel?
+        if (!transparent) {
             qCDebug(modelLog) << "Image with alpha channel is completely opaque:" << QString(srcImageName.c_str());
             image = image.convertToFormat(QImage::Format_RGB888);
         }
-        
-        averageColor = QColor(redTotal / imageArea,
-                              greenTotal / imageArea, blueTotal / imageArea, alphaTotal / imageArea);
-        
-        //isTransparent = (translucentPixels >= imageArea / 2);
+    } 
+    
+    if (!image.hasAlphaChannel() && image.format() != QImage::Format_RGB888) {
+        image = image.convertToFormat(QImage::Format_RGB888);
     }
     
     gpu::Texture* theTexture = nullptr;
     if ((image.width() > 0) && (image.height() > 0)) {
-        
         // bool isLinearRGB = true; //(_type == NORMAL_TEXTURE) || (_type == EMISSIVE_TEXTURE);
         bool isLinearRGB = false; //(_type == NORMAL_TEXTURE) || (_type == EMISSIVE_TEXTURE);
-        
+
         gpu::Element formatGPU = gpu::Element(gpu::VEC3, gpu::NUINT8, (isLinearRGB ? gpu::RGB : gpu::SRGB));
         gpu::Element formatMip = gpu::Element(gpu::VEC3, gpu::NUINT8, (isLinearRGB ? gpu::RGB : gpu::SRGB));
         if (image.hasAlphaChannel()) {
             formatGPU = gpu::Element(gpu::VEC4, gpu::NUINT8, (isLinearRGB ? gpu::RGBA : gpu::SRGBA));
             formatMip = gpu::Element(gpu::VEC4, gpu::NUINT8, (isLinearRGB ? gpu::BGRA : gpu::SBGRA));
         }
-        
 
-            theTexture = (gpu::Texture::create2D(formatGPU, image.width(), image.height(), gpu::Sampler(gpu::Sampler::FILTER_MIN_MAG_MIP_LINEAR)));
-            theTexture->assignStoredMip(0, formatMip, image.byteCount(), image.constBits());
-            theTexture->autoGenerateMips(-1);
+        theTexture = (gpu::Texture::create2D(formatGPU, image.width(), image.height(), gpu::Sampler(gpu::Sampler::FILTER_MIN_MAG_MIP_LINEAR)));
+        theTexture->assignStoredMip(0, formatMip, image.byteCount(), image.constBits());
+        theTexture->autoGenerateMips(-1);
+        
+        // FIXME queue for transfer to GPU and block on completion
     }
     
     return theTexture;