1 /* 2 * This source file is part of libRocket, the HTML/CSS Interface Middleware 3 * 4 * For the latest information, see http://www.librocket.com 5 * 6 * Copyright (c) 2008-2010 CodePoint Ltd, Shift Technology Ltd 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a copy 9 * of this software and associated documentation files (the "Software"), to deal 10 * in the Software without restriction, including without limitation the rights 11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 12 * copies of the Software, and to permit persons to whom the Software is 13 * furnished to do so, subject to the following conditions: 14 * 15 * The above copyright notice and this permission notice shall be included in 16 * all copies or substantial portions of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 24 * THE SOFTWARE. 25 * 26 */ 27 28 #ifndef ROCKETCORECONVOLUTIONFILTER_H 29 #define ROCKETCORECONVOLUTIONFILTER_H 30 31 namespace Rocket { 32 namespace Core { 33 34 /** 35 A programmable convolution filter, designed to aid in the generation of texture data by custom 36 FontEffect types. 37 38 @author Peter Curry 39 */ 40 41 class ConvolutionFilter 42 { 43 public: 44 enum FilterOperation 45 { 46 // The result is the median value of all the filtered pixels. 47 MEDIAN, 48 // The result is the smallest value of all filtered pixels. 49 DILATION, 50 // The result is the largest value of all the filtered pixels. 51 EROSION 52 }; 53 54 ConvolutionFilter(); 55 ~ConvolutionFilter(); 56 57 /// Initialises the filter. A filter must be initialised and populated with values before use. 58 /// @param[in] kernel_size The size of the filter's kernel each side of the origin. So, for example, a filter initialised with a size of 1 will store 9 values. 59 /// @param[in] operation The operation the filter conducts to determine the result. 60 bool Initialise(int kernel_size, FilterOperation operation = MEDIAN); 61 62 /// Returns a reference to one of the rows of the filter kernel. 63 /// @param[in] index The index of the desired row. 64 /// @return The row of kernel values. 65 float* operator[](int index); 66 67 /// Runs the convolution filter. The filter will operate on each pixel in the destination 68 /// surface, setting its opacity to the result the filter on the source opacity values. The 69 /// colour values will remain unchanged. 70 /// @param[in] destination The RGBA-encoded destination buffer. 71 /// @param[in] destination_dimensions The size of the destination region (in pixels). 72 /// @param[in] destination_stride The stride (in bytes) of the destination region. 73 /// @param[in] source The opacity information for the source buffer. 74 /// @param[in] source_dimensions The size of the source region (in pixels). The stride is assumed to be equivalent to the horizontal width. 75 /// @param[in] source_offset The offset of the source region from the destination region. This is usually the same as the kernel size. 76 void Run(byte* destination, const Vector2i& destination_dimensions, int destination_stride, const byte* source, const Vector2i& source_dimensions, const Vector2i& source_offset) const; 77 78 private: 79 int kernel_size; 80 float* kernel; 81 82 FilterOperation operation; 83 }; 84 85 } 86 } 87 88 #endif 89 90