diff --git a/src/filters/filter_helper.cpp b/src/filters/filter_helper.cpp new file mode 100644 index 00000000..9dfc7df0 --- /dev/null +++ b/src/filters/filter_helper.cpp @@ -0,0 +1,70 @@ +#include "filter_helper.hpp" + +//Convert a 32 bit image to a 24 bit one +void convert32To24(u32* src,u8* dst,unsigned int width, unsigned int height) +{ + //Need src as a single byte pointer for this to work + u8 * u8src = (u8*)src; + + for(unsigned int y = 0; y < height ; y++) + { + for(unsigned int x = 0; x < width; x++) + { + //For each pixel copy r,g,b one byte at a time + for(unsigned int i = 0; i<3; i++) + { + *dst++ = *u8src++; + } + //Skip the alpha channel + u8src++; + } + } +} + +//Get a pointer to the first pixel of a row inside an image +u32 * GetVerticalOffset(u32 * image_pointer,unsigned int width,unsigned int vertical_offset,unsigned int scale=1) +{ + return image_pointer + (width * vertical_offset*scale*scale); +} + +//Split an image into multiple sections, with each section being a certain number of rows of the original image +std::vector splitImage(raw_image inImage, unsigned int number) +{ + std::vector outImages; + raw_image outImage; + + //Handle if the user accidentally gave us a zero for number + if(number <= 0) + { + number = 1; + } + + //The height of each image + unsigned int band_height = inImage.height/number; + //Don't let the last few rows get lost + unsigned int remainder_height = inImage.height%number; + + //Start by setting the out pointer to the same as the in pointer + outImage.image = inImage.image; + //All images are the same width + outImage.width=inImage.width; + //All but the last are the same height + outImage.height=band_height; + + //Process all but the last image + for(unsigned int i=0;i<(number-1);++i) + { + //Store the output image + outImages.push_back(outImage); + //Prepare for the next one (move the pointer band_height rows down) + outImage.image=outImage.image+(outImage.width*band_height); + } + + //Process the last image (including the remainder) + outImage.height=band_height+remainder_height; + //Pointer manipulation was handled in the for loop + outImages.push_back(outImage); + + //Give the user the results + return outImages; +} diff --git a/src/filters/filter_helper.hpp b/src/filters/filter_helper.hpp index 726e2447..72bab7ec 100644 --- a/src/filters/filter_helper.hpp +++ b/src/filters/filter_helper.hpp @@ -3,6 +3,10 @@ #ifndef FILTER_HELPER_HPP #define FILTER_HELPER_HPP +#include + +#include +typedef uint32_t u32; /** * Convert a 32 bit image to a 24 bit one @@ -15,26 +19,7 @@ * \param[in] width The image width (in pixels) * \param[in] height The height width (in pixels) */ -inline void convert32To24(u32* src,u8* dst,unsigned int width, unsigned int height) -{ - //Need src as a single byte pointer for this to work - u8 * u8src = (u8*)src; - - for(unsigned int y = 0; y < height ; y++) - { - for(unsigned int x = 0; x < width; x++) - { - //For each pixel copy r,g,b one byte at a time - for(unsigned int i = 0; i<3; i++) - { - *dst++ = *u8src++; - } - //Skip the alpha channel - u8src++; - } - } -} - +void convert32To24(u32* src,u8* dst,unsigned int width, unsigned int height); /** * Get a pointer to the first pixel of a row inside an image * @@ -46,9 +31,27 @@ inline void convert32To24(u32* src,u8* dst,unsigned int width, unsigned int heig * \param[in] scale How much larger the output image will be * \return A pointer to the first pixel in the chosen row */ -inline u32 * GetVerticalOffset(u32 * image_pointer,unsigned int width,unsigned int vertical_offset,unsigned int scale=1) +inline u32 * GetVerticalOffset(u32 * image_pointer,unsigned int width,unsigned int vertical_offset,unsigned int scale=1); + +/** + * A simple struct to keep track of an image pointer, and the image's size. + */ +struct raw_image { - return image_pointer + (width * vertical_offset*scale*scale); -} + u32* image; + unsigned int width; + unsigned int height; +}; + +/** + * Split an image into multiple sections, with each section being a certain number of rows of the original image + * + * NOTE: The returned images are not separate. The pointers merely point to different parts of the original image. + * + * \param[in] inImage The original image + * \param[in] number The number of sections to split the image into + * \return A vector containing the sections of the original image + */ +std::vector splitImage(raw_image inImage, unsigned int number); #endif //FILTER_HELPER_HPP