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Default font encoded as base85 saves ~100 lines / 26 KB of source code (from @mmalex)

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This commit is contained in:
ocornut
2015-07-30 19:36:55 -06:00
parent fddc871870
commit 527208ad7c
2 changed files with 160 additions and 233 deletions
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74
extra_fonts/binary_to_compressed_c.cpp
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@ -1,8 +1,10 @@
// ImGui - binary_to_compressed_c.cpp
// Helper tool to turn a file into a C array.
// The data is first compressed with stb_compress() to reduce source code size a little.
// The data is first compressed with stb_compress() to reduce source code size.
// Then encoded in Base85 to fit in a string so we can fit roughly 4 bytes of compressed data into 5 bytes of source code (suggested by @mmalex)
// (If we used 32-bits constants it would require take 11 bytes of source code to encode 4 bytes.)
// Useful if you want to embed fonts into your code.
// Note that the output array is likely to be bigger than the binary file..
// Note that even with compression, the output array is likely to be bigger than the binary file..
// Load compressed TTF fonts with ImGui::GetIO().Fonts->AddFontFromMemoryCompressedTTF()
#define _CRT_SECURE_NO_WARNINGS
@ -11,28 +13,44 @@
#include <stdlib.h>
#include <assert.h>
const int COLUMNS = 12;
// stb_compress* from stb.h - declaration
typedef unsigned int stb_uint;
typedef unsigned char stb_uchar;
stb_uint stb_compress(stb_uchar *out,stb_uchar *in,stb_uint len);
static bool binary_to_compressed_c(const char* filename, const char* symbol);
static bool binary_to_compressed_c(const char* filename, const char* symbol, bool use_base85_encoding);
int main(int argc, char** argv)
{
if (argc < 3)
{
printf("Syntax: %s <inputfile> <symbolname>\n", argv[0]);
printf("Syntax: %s [-base85] <inputfile> <symbolname>\n", argv[0]);
return 0;
}
binary_to_compressed_c(argv[1], argv[2]);
int argn = 1;
bool use_base85_encoding = false;
if (argv[argn][0] == '-')
{
if (strcmp(argv[argn], "-base85") == 0) { use_base85_encoding = true; argn++; }
else
{
printf("Unknown argument: '%s'\n", argv[argn]);
return 1;
}
}
binary_to_compressed_c(argv[argn], argv[argn+1], use_base85_encoding);
return 1;
}
bool binary_to_compressed_c(const char* filename, const char* symbol)
char Encode85Byte(unsigned int x)
{
x = (x % 85) + 35;
return (x>='\\') ? x+1 : x;
}
bool binary_to_compressed_c(const char* filename, const char* symbol, bool use_base85_encoding)
{
// Read file
FILE* f = fopen(filename, "rb");
@ -50,22 +68,38 @@ bool binary_to_compressed_c(const char* filename, const char* symbol)
int compressed_sz = stb_compress((stb_uchar*)compressed, (stb_uchar*)data, data_sz);
memset(compressed + compressed_sz, 0, maxlen - compressed_sz);
// Output
// Output as Base85 encoded
FILE* out = stdout;
fprintf(out, "// File: '%s' (%d bytes)\n", filename, (int)data_sz);
fprintf(out, "// Exported using binary_to_compressed_c\n");
fprintf(out, "static const unsigned int %s_compressed_size = %d;\n", symbol, (int)compressed_sz);
fprintf(out, "static const unsigned int %s_compressed_data[%d/4] =\n{", symbol, (int)((compressed_sz+3)/4)*4);
int column = 0;
for (int i = 0; i < compressed_sz; i += 4)
fprintf(out, "// Exported using binary_to_compressed_c.cpp\n");
if (use_base85_encoding)
{
unsigned int d = *(unsigned int*)(compressed + i);
if ((column++ % COLUMNS) == 0)
fprintf(out, "\n 0x%08x, ", d);
else
fprintf(out, "0x%08x, ", d);
fprintf(out, "static const char %s_compressed_data_base85[%d+1] =\n \"", symbol, (int)((compressed_sz+3)/4)*5);
int column = 0;
for (int i = 0; i < compressed_sz; i += 4)
{
unsigned int d = *(unsigned int*)(compressed + i);
fprintf(out, "%c%c%c%c%c", Encode85Byte(d), Encode85Byte(d/85), Encode85Byte(d/7225), Encode85Byte(d/614125), Encode85Byte(d/52200625));
if ((i % 112) == 112-4)
fprintf(out, "\"\n \"");
}
fprintf(out, "\";\n\n");
}
else
{
fprintf(out, "static const unsigned int %s_compressed_size = %d;\n", symbol, (int)compressed_sz);
fprintf(out, "static const unsigned int %s_compressed_data[%d/4] =\n{", symbol, (int)((compressed_sz+3)/4)*4);
int column = 0;
for (int i = 0; i < compressed_sz; i += 4)
{
unsigned int d = *(unsigned int*)(compressed + i);
if ((column++ % 12) == 0)
fprintf(out, "\n 0x%08x, ", d);
else
fprintf(out, "0x%08x, ", d);
}
fprintf(out, "\n};\n\n");
}
fprintf(out, "\n};\n\n");
// Cleanup
delete[] data;