67 lines
1.9 KiB
C
67 lines
1.9 KiB
C
#include "pngwriter.h"
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#include <stdlib.h>
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png_data *png_create(int nWidth, int nHeight) {
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int i;
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png_data *pData = (png_data *)malloc(sizeof(png_data));
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pData->nWidth = nWidth;
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pData->nHeight = nHeight;
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pData->pPixels = (png_bytepp)malloc(nHeight * sizeof(png_bytep));
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for (i = 0; i < nHeight; i++)
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pData->pPixels[i] = (png_bytep)malloc(3 * nWidth * sizeof(png_byte));
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return pData;
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}
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#define CHECK_RGB_BOUNDS(x) \
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if (x > 255) \
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x = 255; \
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if (x < 0) \
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x = 0;
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void png_plot(png_data *pData, int x, int y, int r, int g, int b) {
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if (x >= pData->nWidth)
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return;
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if (y >= pData->nHeight)
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return;
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CHECK_RGB_BOUNDS(r)
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CHECK_RGB_BOUNDS(g)
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CHECK_RGB_BOUNDS(b)
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pData->pPixels[pData->nHeight - y - 1][3 * x - 3] = (char)r;
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pData->pPixels[pData->nHeight - y - 1][3 * x - 2] = (char)g;
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pData->pPixels[pData->nHeight - y - 1][3 * x - 1] = (char)b;
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}
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void png_write(png_data *pData, char *szFileName) {
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FILE *fp;
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png_structp png_ptr;
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png_infop info_ptr;
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fp = fopen(szFileName, "wb");
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if (fp == NULL)
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return;
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png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
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info_ptr = png_create_info_struct(png_ptr);
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png_init_io(png_ptr, fp);
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png_set_compression_level(png_ptr, PNGWRITER_DEFAULT_COMPRESSION);
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png_set_IHDR(png_ptr, info_ptr, pData->nWidth, pData->nHeight, 8,
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PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
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PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
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png_set_gAMA(png_ptr, info_ptr, 0.7);
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png_write_info(png_ptr, info_ptr);
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png_write_image(png_ptr, pData->pPixels);
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png_write_end(png_ptr, info_ptr);
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png_destroy_write_struct(&png_ptr, &info_ptr);
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fclose(fp);
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free(pData);
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}
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