1 files changed, 86 insertions, 0 deletions
diff --git a/thirdparty/etcpak/BitmapDownsampled.cpp b/thirdparty/etcpak/BitmapDownsampled.cpp
new file mode 100644
index 0000000000..0eb0d81185
--- /dev/null
+++ b/thirdparty/etcpak/BitmapDownsampled.cpp
@@ -0,0 +1,86 @@
+#include <string.h>
+#include <utility>
+
+#include "BitmapDownsampled.hpp"
+#include "Debug.hpp"
+
+BitmapDownsampled::BitmapDownsampled( const Bitmap& bmp, unsigned int lines )
+    : Bitmap( bmp, lines )
+{
+    m_size.x = std::max( 1, bmp.Size().x / 2 );
+    m_size.y = std::max( 1, bmp.Size().y / 2 );
+
+    int w = std::max( m_size.x, 4 );
+    int h = std::max( m_size.y, 4 );
+
+    DBGPRINT( "Subbitmap " << m_size.x << "x" << m_size.y );
+
+    m_block = m_data = new uint32_t[w*h];
+
+    if( m_size.x < w || m_size.y < h )
+    {
+        memset( m_data, 0, w*h*sizeof( uint32_t ) );
+        m_linesLeft = h / 4;
+        unsigned int lines = 0;
+        for( int i=0; i<h/4; i++ )
+        {
+            for( int j=0; j<4; j++ )
+            {
+                lines++;
+                if( lines > m_lines )
+                {
+                    lines = 0;
+                    m_sema.unlock();
+                }
+            }
+        }
+        if( lines != 0 )
+        {
+            m_sema.unlock();
+        }
+    }
+    else
+    {
+        m_linesLeft = h / 4;
+        m_load = std::async( std::launch::async, [this, &bmp, w, h]() mutable
+        {
+            auto ptr = m_data;
+            auto src1 = bmp.Data();
+            auto src2 = src1 + bmp.Size().x;
+            unsigned int lines = 0;
+            for( int i=0; i<h/4; i++ )
+            {
+                for( int j=0; j<4; j++ )
+                {
+                    for( int k=0; k<m_size.x; k++ )
+                    {
+                        int r = ( ( *src1 & 0x000000FF ) + ( *(src1+1) & 0x000000FF ) + ( *src2 & 0x000000FF ) + ( *(src2+1) & 0x000000FF ) ) / 4;
+                        int g = ( ( ( *src1 & 0x0000FF00 ) + ( *(src1+1) & 0x0000FF00 ) + ( *src2 & 0x0000FF00 ) + ( *(src2+1) & 0x0000FF00 ) ) / 4 ) & 0x0000FF00;
+                        int b = ( ( ( *src1 & 0x00FF0000 ) + ( *(src1+1) & 0x00FF0000 ) + ( *src2 & 0x00FF0000 ) + ( *(src2+1) & 0x00FF0000 ) ) / 4 ) & 0x00FF0000;
+                        int a = ( ( ( ( ( *src1 & 0xFF000000 ) >> 8 ) + ( ( *(src1+1) & 0xFF000000 ) >> 8 ) + ( ( *src2 & 0xFF000000 ) >> 8 ) + ( ( *(src2+1) & 0xFF000000 ) >> 8 ) ) / 4 ) & 0x00FF0000 ) << 8;
+                        *ptr++ = r | g | b | a;
+                        src1 += 2;
+                        src2 += 2;
+                    }
+                    src1 += m_size.x * 2;
+                    src2 += m_size.x * 2;
+                }
+                lines++;
+                if( lines >= m_lines )
+                {
+                    lines = 0;
+                    m_sema.unlock();
+                }
+            }
+
+            if( lines != 0 )
+            {
+                m_sema.unlock();
+            }
+        } );
+    }
+}
+
+BitmapDownsampled::~BitmapDownsampled()
+{
+}