[opencl] Fix hillshade renderer with 16bit rasters

Fixes #21121

Author: elpaso

resources/opencl_programs/hillshade_renderer.cl

@@ -1,3 +1,4 @@
+// Note: "float *scanLine" may be replaced by code with actual input data type
 __kernel void processNineCellWindow( __global float *scanLine1,
                                      __global float *scanLine2,
                                      __global float *scanLine3,
@@ -39,8 +40,8 @@ __kernel void processNineCellWindow( __global float *scanLine1,
         if ( x32 == rasterParams[0] ) x32 = x22;
         if ( x33 == rasterParams[0] ) x33 = x22;
 
-        float derX = ( ( x13 + x23 + x23 + x33 ) - ( x11 + x21 + x21 + x31 ) ) / ( 8 * rasterParams[3] );
-        float derY = ( ( x31 + x32 + x32 + x33 ) - ( x11 + x12 + x12 + x13 ) ) / ( 8 * -rasterParams[4]);
+        float derX = ( ( x13 + x23 + x23 + x33 ) - ( x11 + x21 + x21 + x31 ) ) / ( 8.0f * rasterParams[3] );
+        float derY = ( ( x31 + x32 + x32 + x33 ) - ( x11 + x12 + x12 + x13 ) ) / ( 8.0f * -rasterParams[4]);
 
         if ( derX == rasterParams[0] ||
              derX == rasterParams[0] )
@@ -90,7 +91,7 @@ __kernel void processNineCellWindow( __global float *scanLine1,
                                              weight_270 * val270_mul_127 +
                                              weight_315 * val315_mul_127 +
                                              weight_360 * val360_mul_127 ) / xx_plus_yy ) /
-                                         ( 1 + rasterParams[8] * xx_plus_yy );
+                                         ( 1.0f + rasterParams[8] * xx_plus_yy );
               res = clamp( 1.0f + cang_mul_127, 0.0f, 255.0f );
             }
           }
@@ -99,7 +100,7 @@ __kernel void processNineCellWindow( __global float *scanLine1,
             res = ( rasterParams[9] -
                     ( derY * rasterParams[6] -
                       derX * rasterParams[7] )) /
-                      sqrt( 1 + rasterParams[8] *
+                      sqrt( 1.0f + rasterParams[8] *
                       ( derX * derX + derY * derY ) );
             res = res <= 0.0f ? 1.0f : 1.0f + res;
           }

src/core/raster/qgshillshaderenderer.cpp

@@ -30,7 +30,9 @@
 #include <chrono>
 #include "qgssettings.h"
 #endif
+#include "qgsexception.h"
 #include "qgsopenclutils.h"
+#include "qdebug.h"
 #endif
 
 QgsHillshadeRenderer::QgsHillshadeRenderer( QgsRasterInterface *input, int band, double lightAzimuth, double lightAngle ):
@@ -165,7 +167,8 @@ QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &ext
   bool useOpenCL( QgsOpenClUtils::enabled()
                   && QgsOpenClUtils::available()
                   && ( ! mRasterTransparency || mRasterTransparency->isEmpty() )
-                  && mAlphaBand <= 0 );
+                  && mAlphaBand <= 0
+                  && inputBlock->dataTypeSize() <= 4 );
   // Check for sources
   QString source;
   if ( useOpenCL )
@@ -190,6 +193,37 @@ QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &ext
       std::size_t inputDataTypeSize = inputBlock->dataTypeSize();
       std::size_t outputDataTypeSize = outputBlock->dataTypeSize();
       // Buffer scanline, 1px height, 2px wider
+      QString typeName;
+      switch ( inputBlock->dataType() )
+      {
+        case Qgis::DataType::Byte:
+          typeName = QStringLiteral( "unsigned char" );
+          break;
+        case Qgis::DataType::UInt16:
+          typeName = QStringLiteral( "unsigned int" );
+          break;
+        case Qgis::DataType::Int16:
+          typeName = QStringLiteral( "short" );
+          break;
+        case Qgis::DataType::UInt32:
+          typeName = QStringLiteral( "unsigned int" );
+          break;
+        case Qgis::DataType::Int32:
+          typeName = QStringLiteral( "int" );
+          break;
+        case Qgis::DataType::Float32:
+          typeName = QStringLiteral( "float" );
+          break;
+        default:
+          throw QgsException( QStringLiteral( "Unsupported data type for OpenCL processing.") );
+      }
+
+      if ( inputBlock->dataType() != Qgis::DataType::Float32 )
+      {
+        source.replace(QStringLiteral( "__global float *scanLine" ), QStringLiteral( "__global %1 *scanLine" ).arg( typeName ));
+      }
+      qDebug() << source;
+
       // Data type for input is Float32 (4 bytes)
       std::size_t scanLineWidth( inputBlock->width() + 2 );
       std::size_t inputSize( inputDataTypeSize * inputBlock->width() );
@@ -236,7 +270,6 @@ QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &ext
       // Whether use multidirectional
       rasterParams.push_back( static_cast<float>( mMultiDirectional ) ); // 17
 
-
       cl::Buffer rasterParamsBuffer( queue, rasterParams.begin(), rasterParams.end(), true, false, nullptr );
       cl::Buffer scanLine1Buffer( ctx, CL_MEM_READ_ONLY, bufferSize, nullptr, nullptr );
       cl::Buffer scanLine2Buffer( ctx, CL_MEM_READ_ONLY, bufferSize, nullptr, nullptr );
@@ -245,13 +278,14 @@ QgsRasterBlock *QgsHillshadeRenderer::block( int bandNo, const QgsRectangle &ext
       // Note that result buffer is an image
       cl::Buffer resultLineBuffer( ctx, CL_MEM_WRITE_ONLY, outputDataTypeSize * width, nullptr, nullptr );
 
-      static cl::Program program;
-      static std::once_flag programBuilt;
-      std::call_once( programBuilt, [ = ]()
+      static std::map<Qgis::DataType, cl::Program> programCache;
+      cl::Program program = programCache[inputBlock->dataType()];
+      if (! program.get() )
       {
         // Create a program from the kernel source
-        program = QgsOpenClUtils::buildProgram( source, QgsOpenClUtils::ExceptionBehavior::Throw );
-      } );
+        programCache[inputBlock->dataType()] = QgsOpenClUtils::buildProgram( source, QgsOpenClUtils::ExceptionBehavior::Throw );
+        program = programCache[inputBlock->dataType()];
+      }
 
       // Disable program cache when developing and testing cl program
       // program = QgsOpenClUtils::buildProgram( ctx, source, QgsOpenClUtils::ExceptionBehavior::Throw );