mirror of
https://github.com/dborth/snes9xgx.git
synced 2024-11-01 08:25:18 +01:00
727 lines
21 KiB
C
727 lines
21 KiB
C
/********************************************************************************************
|
|
|
|
PNGU Version : 0.2a
|
|
|
|
Coder : frontier
|
|
|
|
More info : http://frontier-dev.net
|
|
|
|
Modified by Tantric, 2009
|
|
|
|
********************************************************************************************/
|
|
#include <stdio.h>
|
|
#include <malloc.h>
|
|
#include "pngu.h"
|
|
#include "png.h"
|
|
|
|
// Constants
|
|
#define PNGU_SOURCE_BUFFER 1
|
|
#define PNGU_SOURCE_DEVICE 2
|
|
|
|
// Prototypes of helper functions
|
|
int pngu_info (IMGCTX ctx);
|
|
int pngu_decode (IMGCTX ctx, PNGU_u32 width, PNGU_u32 height, PNGU_u32 stripAlpha);
|
|
void pngu_free_info (IMGCTX ctx);
|
|
void pngu_read_data_from_buffer (png_structp png_ptr, png_bytep data, png_size_t length);
|
|
void pngu_write_data_to_buffer (png_structp png_ptr, png_bytep data, png_size_t length);
|
|
void pngu_flush_data_to_buffer (png_structp png_ptr);
|
|
int pngu_clamp (int value, int min, int max);
|
|
|
|
// PNGU Image context struct
|
|
struct _IMGCTX
|
|
{
|
|
int source;
|
|
void *buffer;
|
|
char *filename;
|
|
PNGU_u32 cursor;
|
|
|
|
PNGU_u32 propRead;
|
|
PNGUPROP prop;
|
|
|
|
PNGU_u32 infoRead;
|
|
png_structp png_ptr;
|
|
png_infop info_ptr;
|
|
FILE *fd;
|
|
|
|
png_bytep *row_pointers;
|
|
png_bytep img_data;
|
|
};
|
|
|
|
// PNGU Implementation
|
|
|
|
IMGCTX PNGU_SelectImageFromBuffer (const void *buffer)
|
|
{
|
|
IMGCTX ctx = NULL;
|
|
|
|
if (!buffer)
|
|
return NULL;
|
|
|
|
ctx = malloc (sizeof (struct _IMGCTX));
|
|
if (!ctx)
|
|
return NULL;
|
|
|
|
ctx->buffer = (void *) buffer;
|
|
ctx->source = PNGU_SOURCE_BUFFER;
|
|
ctx->cursor = 0;
|
|
ctx->filename = NULL;
|
|
ctx->propRead = 0;
|
|
ctx->infoRead = 0;
|
|
|
|
return ctx;
|
|
}
|
|
|
|
IMGCTX PNGU_SelectImageFromDevice (const char *filename)
|
|
{
|
|
IMGCTX ctx = NULL;
|
|
|
|
if (!filename)
|
|
return NULL;
|
|
|
|
ctx = malloc (sizeof (struct _IMGCTX));
|
|
if (!ctx)
|
|
return NULL;
|
|
|
|
ctx->buffer = NULL;
|
|
ctx->source = PNGU_SOURCE_DEVICE;
|
|
ctx->cursor = 0;
|
|
|
|
ctx->filename = malloc (strlen (filename) + 1);
|
|
if (!ctx->filename)
|
|
{
|
|
free (ctx);
|
|
return NULL;
|
|
}
|
|
strcpy(ctx->filename, filename);
|
|
|
|
ctx->propRead = 0;
|
|
ctx->infoRead = 0;
|
|
|
|
return ctx;
|
|
}
|
|
|
|
void PNGU_ReleaseImageContext (IMGCTX ctx)
|
|
{
|
|
if (!ctx)
|
|
return;
|
|
|
|
if (ctx->filename)
|
|
free (ctx->filename);
|
|
|
|
if ((ctx->propRead) && (ctx->prop.trans))
|
|
free (ctx->prop.trans);
|
|
|
|
pngu_free_info (ctx);
|
|
free (ctx);
|
|
}
|
|
|
|
int PNGU_GetImageProperties (IMGCTX ctx, PNGUPROP *imgprop)
|
|
{
|
|
int res;
|
|
|
|
if (!ctx->propRead)
|
|
{
|
|
res = pngu_info (ctx);
|
|
if (res != PNGU_OK)
|
|
return res;
|
|
}
|
|
|
|
*imgprop = ctx->prop;
|
|
return PNGU_OK;
|
|
}
|
|
|
|
int PNGU_DecodeTo4x4RGBA8 (IMGCTX ctx, PNGU_u32 width, PNGU_u32 height, void *buffer, PNGU_u8 default_alpha)
|
|
{
|
|
int result;
|
|
PNGU_u32 x, y, qwidth, qheight;
|
|
PNGU_u64 alphaMask;
|
|
|
|
// width and height need to be divisible by four
|
|
if ((width % 4) || (height % 4))
|
|
return PNGU_INVALID_WIDTH_OR_HEIGHT;
|
|
|
|
result = pngu_decode (ctx, width, height, 0);
|
|
if (result != PNGU_OK)
|
|
return result;
|
|
|
|
// Init some variables
|
|
qwidth = width >> 2;
|
|
qheight = height >> 2;
|
|
|
|
// Check is source image has an alpha channel
|
|
if ( (ctx->prop.imgColorType == PNGU_COLOR_TYPE_GRAY_ALPHA) || (ctx->prop.imgColorType == PNGU_COLOR_TYPE_RGB_ALPHA) )
|
|
{
|
|
// Alpha channel present, copy image to the output buffer
|
|
for (y = 0; y < qheight; y++)
|
|
for (x = 0; x < qwidth; x++)
|
|
{
|
|
int blockbase = (y * qwidth + x) << 3;
|
|
|
|
PNGU_u32 y4 = y << 2;
|
|
PNGU_u32 x16 = x << 4;
|
|
|
|
PNGU_u64 fieldA = *((PNGU_u64 *)(ctx->row_pointers[y4]+x16));
|
|
PNGU_u64 fieldB = *((PNGU_u64 *)(ctx->row_pointers[y4]+x16+8));
|
|
((PNGU_u64 *) buffer)[blockbase] =
|
|
((fieldA & 0xFF00000000ULL) << 24) | ((fieldA & 0xFF00000000000000ULL) >> 8) |
|
|
((fieldA & 0xFFULL) << 40) | ((fieldA & 0xFF000000ULL) << 8) |
|
|
((fieldB & 0xFF00000000ULL) >> 8) | ((fieldB & 0xFF00000000000000ULL) >> 40) |
|
|
((fieldB & 0xFFULL) << 8) | ((fieldB & 0xFF000000ULL) >> 24);
|
|
((PNGU_u64 *) buffer)[blockbase+4] =
|
|
((fieldA & 0xFFFF0000000000ULL) << 8) | ((fieldA & 0xFFFF00ULL) << 24) |
|
|
((fieldB & 0xFFFF0000000000ULL) >> 24) | ((fieldB & 0xFFFF00ULL) >> 8);
|
|
|
|
fieldA = *((PNGU_u64 *)(ctx->row_pointers[y4+1]+x16));
|
|
fieldB = *((PNGU_u64 *)(ctx->row_pointers[y4+1]+x16+8));
|
|
((PNGU_u64 *) buffer)[blockbase+1] =
|
|
((fieldA & 0xFF00000000ULL) << 24) | ((fieldA & 0xFF00000000000000ULL) >> 8) |
|
|
((fieldA & 0xFFULL) << 40) | ((fieldA & 0xFF000000ULL) << 8) |
|
|
((fieldB & 0xFF00000000ULL) >> 8) | ((fieldB & 0xFF00000000000000ULL) >> 40) |
|
|
((fieldB & 0xFFULL) << 8) | ((fieldB & 0xFF000000ULL) >> 24);
|
|
((PNGU_u64 *) buffer)[blockbase+5] =
|
|
((fieldA & 0xFFFF0000000000ULL) << 8) | ((fieldA & 0xFFFF00ULL) << 24) |
|
|
((fieldB & 0xFFFF0000000000ULL) >> 24) | ((fieldB & 0xFFFF00ULL) >> 8);
|
|
|
|
fieldA = *((PNGU_u64 *)(ctx->row_pointers[y4+2]+x16));
|
|
fieldB = *((PNGU_u64 *)(ctx->row_pointers[y4+2]+x16+8));
|
|
((PNGU_u64 *) buffer)[blockbase+2] =
|
|
((fieldA & 0xFF00000000ULL) << 24) | ((fieldA & 0xFF00000000000000ULL) >> 8) |
|
|
((fieldA & 0xFFULL) << 40) | ((fieldA & 0xFF000000ULL) << 8) |
|
|
((fieldB & 0xFF00000000ULL) >> 8) | ((fieldB & 0xFF00000000000000ULL) >> 40) |
|
|
((fieldB & 0xFFULL) << 8) | ((fieldB & 0xFF000000ULL) >> 24);
|
|
((PNGU_u64 *) buffer)[blockbase+6] =
|
|
((fieldA & 0xFFFF0000000000ULL) << 8) | ((fieldA & 0xFFFF00ULL) << 24) |
|
|
((fieldB & 0xFFFF0000000000ULL) >> 24) | ((fieldB & 0xFFFF00ULL) >> 8);
|
|
|
|
fieldA = *((PNGU_u64 *)(ctx->row_pointers[y4+3]+x16));
|
|
fieldB = *((PNGU_u64 *)(ctx->row_pointers[y4+3]+x16+8));
|
|
((PNGU_u64 *) buffer)[blockbase+3] =
|
|
((fieldA & 0xFF00000000ULL) << 24) | ((fieldA & 0xFF00000000000000ULL) >> 8) |
|
|
((fieldA & 0xFFULL) << 40) | ((fieldA & 0xFF000000ULL) << 8) |
|
|
((fieldB & 0xFF00000000ULL) >> 8) | ((fieldB & 0xFF00000000000000ULL) >> 40) |
|
|
((fieldB & 0xFFULL) << 8) | ((fieldB & 0xFF000000ULL) >> 24);
|
|
((PNGU_u64 *) buffer)[blockbase+7] =
|
|
((fieldA & 0xFFFF0000000000ULL) << 8) | ((fieldA & 0xFFFF00ULL) << 24) |
|
|
((fieldB & 0xFFFF0000000000ULL) >> 24) | ((fieldB & 0xFFFF00ULL) >> 8);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// No alpha channel present, copy image to the output buffer
|
|
alphaMask = (((PNGU_u64)default_alpha) << 56) | (((PNGU_u64)default_alpha) << 40) |
|
|
(((PNGU_u64)default_alpha) << 24) | (((PNGU_u64)default_alpha) << 8);
|
|
|
|
for (y = 0; y < qheight; y++)
|
|
for (x = 0; x < qwidth; x++)
|
|
{
|
|
int blockbase = (y * qwidth + x) << 3;
|
|
|
|
PNGU_u32 y4 = y << 2;
|
|
PNGU_u32 x12 = x * 12;
|
|
|
|
PNGU_u64 field64 = *((PNGU_u64 *)(ctx->row_pointers[y4]+x12));
|
|
PNGU_u64 field32 = (PNGU_u64) *((PNGU_u32 *)(ctx->row_pointers[y4]+x12+8));
|
|
((PNGU_u64 *) buffer)[blockbase] =
|
|
(((field64 & 0xFF00000000000000ULL) >> 8) | (field64 & 0xFF00000000ULL) |
|
|
((field64 & 0xFF00ULL) << 8) | ((field32 & 0xFF0000ULL) >> 16) | alphaMask);
|
|
((PNGU_u64 *) buffer)[blockbase+4] =
|
|
(((field64 & 0xFFFF0000000000ULL) << 8) | ((field64 & 0xFFFF0000ULL) << 16) |
|
|
((field64 & 0xFFULL) << 24) | ((field32 & 0xFF000000ULL) >> 8) | (field32 & 0xFFFFULL));
|
|
|
|
field64 = *((PNGU_u64 *)(ctx->row_pointers[y4+1]+x12));
|
|
field32 = (PNGU_u64) *((PNGU_u32 *)(ctx->row_pointers[y4+1]+x12+8));
|
|
((PNGU_u64 *) buffer)[blockbase+1] =
|
|
(((field64 & 0xFF00000000000000ULL) >> 8) | (field64 & 0xFF00000000ULL) |
|
|
((field64 & 0xFF00ULL) << 8) | ((field32 & 0xFF0000ULL) >> 16) | alphaMask);
|
|
((PNGU_u64 *) buffer)[blockbase+5] =
|
|
(((field64 & 0xFFFF0000000000ULL) << 8) | ((field64 & 0xFFFF0000ULL) << 16) |
|
|
((field64 & 0xFFULL) << 24) | ((field32 & 0xFF000000ULL) >> 8) | (field32 & 0xFFFFULL));
|
|
|
|
field64 = *((PNGU_u64 *)(ctx->row_pointers[y4+2]+x12));
|
|
field32 = (PNGU_u64) *((PNGU_u32 *)(ctx->row_pointers[y4+2]+x12+8));
|
|
((PNGU_u64 *) buffer)[blockbase+2] =
|
|
(((field64 & 0xFF00000000000000ULL) >> 8) | (field64 & 0xFF00000000ULL) |
|
|
((field64 & 0xFF00ULL) << 8) | ((field32 & 0xFF0000ULL) >> 16) | alphaMask);
|
|
((PNGU_u64 *) buffer)[blockbase+6] =
|
|
(((field64 & 0xFFFF0000000000ULL) << 8) | ((field64 & 0xFFFF0000ULL) << 16) |
|
|
((field64 & 0xFFULL) << 24) | ((field32 & 0xFF000000ULL) >> 8) | (field32 & 0xFFFFULL));
|
|
|
|
field64 = *((PNGU_u64 *)(ctx->row_pointers[y4+3]+x12));
|
|
field32 = (PNGU_u64) *((PNGU_u32 *)(ctx->row_pointers[y4+3]+x12+8));
|
|
((PNGU_u64 *) buffer)[blockbase+3] =
|
|
(((field64 & 0xFF00000000000000ULL) >> 8) | (field64 & 0xFF00000000ULL) |
|
|
((field64 & 0xFF00ULL) << 8) | ((field32 & 0xFF0000ULL) >> 16) | alphaMask);
|
|
((PNGU_u64 *) buffer)[blockbase+7] =
|
|
(((field64 & 0xFFFF0000000000ULL) << 8) | ((field64 & 0xFFFF0000ULL) << 16) |
|
|
((field64 & 0xFFULL) << 24) | ((field32 & 0xFF000000ULL) >> 8) | (field32 & 0xFFFFULL));
|
|
}
|
|
}
|
|
|
|
// Free resources
|
|
free (ctx->img_data);
|
|
free (ctx->row_pointers);
|
|
|
|
// Success
|
|
return PNGU_OK;
|
|
}
|
|
|
|
int PNGU_EncodeFromRGB (IMGCTX ctx, PNGU_u32 width, PNGU_u32 height, void *buffer, PNGU_u32 stride)
|
|
{
|
|
png_uint_32 rowbytes;
|
|
PNGU_u32 y;
|
|
|
|
// Erase from the context any readed info
|
|
pngu_free_info (ctx);
|
|
ctx->propRead = 0;
|
|
|
|
// Check if the user has selected a file to write the image
|
|
if (ctx->source == PNGU_SOURCE_BUFFER);
|
|
|
|
else if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
{
|
|
// Open file
|
|
if (!(ctx->fd = fopen (ctx->filename, "wb")))
|
|
return PNGU_CANT_OPEN_FILE;
|
|
}
|
|
|
|
else
|
|
return PNGU_NO_FILE_SELECTED;
|
|
|
|
// Allocation of libpng structs
|
|
ctx->png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
|
|
if (!(ctx->png_ptr))
|
|
{
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
ctx->info_ptr = png_create_info_struct (ctx->png_ptr);
|
|
if (!(ctx->info_ptr))
|
|
{
|
|
png_destroy_write_struct (&(ctx->png_ptr), (png_infopp)NULL);
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
if (ctx->source == PNGU_SOURCE_BUFFER)
|
|
{
|
|
// Installation of our custom data writer function
|
|
ctx->cursor = 0;
|
|
png_set_write_fn (ctx->png_ptr, ctx, pngu_write_data_to_buffer, pngu_flush_data_to_buffer);
|
|
}
|
|
else if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
{
|
|
// Default data writer uses function fwrite, so it needs to use our FILE*
|
|
png_init_io (ctx->png_ptr, ctx->fd);
|
|
}
|
|
|
|
// Setup output file properties
|
|
png_set_IHDR (ctx->png_ptr, ctx->info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB,
|
|
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
|
|
|
|
// Allocate memory to store the image in RGB format
|
|
rowbytes = width * 3;
|
|
if (rowbytes % 4)
|
|
rowbytes = ((rowbytes >>2) + 1) <<2; // Add extra padding so each row starts in a 4 byte boundary
|
|
|
|
ctx->img_data = malloc(rowbytes * height);
|
|
memset(ctx->img_data, 0, rowbytes * height);
|
|
|
|
if (!ctx->img_data)
|
|
{
|
|
png_destroy_write_struct (&(ctx->png_ptr), (png_infopp)NULL);
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
ctx->row_pointers = malloc (sizeof (png_bytep) * height);
|
|
memset(ctx->row_pointers, 0, sizeof (png_bytep) * height);
|
|
|
|
if (!ctx->row_pointers)
|
|
{
|
|
png_destroy_write_struct (&(ctx->png_ptr), (png_infopp)NULL);
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
for (y = 0; y < height; ++y)
|
|
{
|
|
ctx->row_pointers[y] = buffer + (y * rowbytes);
|
|
}
|
|
|
|
// Tell libpng where is our image data
|
|
png_set_rows (ctx->png_ptr, ctx->info_ptr, ctx->row_pointers);
|
|
|
|
// Write file header and image data
|
|
png_write_png (ctx->png_ptr, ctx->info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
|
|
|
|
// Tell libpng we have no more data to write
|
|
png_write_end (ctx->png_ptr, (png_infop) NULL);
|
|
|
|
// Free resources
|
|
free (ctx->img_data);
|
|
free (ctx->row_pointers);
|
|
png_destroy_write_struct (&(ctx->png_ptr), &(ctx->info_ptr));
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
|
|
// Success
|
|
return ctx->cursor;
|
|
}
|
|
|
|
int PNGU_EncodeFromGXTexture (IMGCTX ctx, PNGU_u32 width, PNGU_u32 height, void *buffer, PNGU_u32 stride)
|
|
{
|
|
int res;
|
|
PNGU_u32 x,y, tmpy1, tmpy2, tmpyWid, tmpxy;
|
|
|
|
unsigned char * ptr = (unsigned char*)buffer;
|
|
unsigned char * tmpbuffer = (unsigned char *)malloc(width*height*3);
|
|
memset(tmpbuffer, 0, width*height*3);
|
|
png_uint_32 offset;
|
|
|
|
for(y=0; y < height; y++)
|
|
{
|
|
tmpy1 = y * 640*3;
|
|
tmpy2 = y%4 << 2;
|
|
tmpyWid = (((y >> 2)<<4)*width);
|
|
|
|
for(x=0; x < width; x++)
|
|
{
|
|
offset = tmpyWid + ((x >> 2)<<6) + ((tmpy2+ x%4 ) << 1);
|
|
tmpxy = x * 3 + tmpy1;
|
|
|
|
tmpbuffer[tmpxy ] = ptr[offset+1]; // R
|
|
tmpbuffer[tmpxy+1] = ptr[offset+32]; // G
|
|
tmpbuffer[tmpxy+2] = ptr[offset+33]; // B
|
|
}
|
|
}
|
|
|
|
res = PNGU_EncodeFromRGB (ctx, width, height, tmpbuffer, stride);
|
|
free(tmpbuffer);
|
|
return res;
|
|
}
|
|
|
|
int pngu_info (IMGCTX ctx)
|
|
{
|
|
png_byte magic[8];
|
|
png_uint_32 width;
|
|
png_uint_32 height;
|
|
png_color_16p background;
|
|
png_bytep trans;
|
|
png_color_16p trans_values;
|
|
int scale, i;
|
|
|
|
// Check if there is a file selected and if it is a valid .png
|
|
if (ctx->source == PNGU_SOURCE_BUFFER)
|
|
memcpy (magic, ctx->buffer, 8);
|
|
|
|
else if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
{
|
|
// Open file
|
|
if (!(ctx->fd = fopen (ctx->filename, "rb")))
|
|
return PNGU_CANT_OPEN_FILE;
|
|
|
|
// Load first 8 bytes into magic buffer
|
|
if (fread (magic, 1, 8, ctx->fd) != 8)
|
|
{
|
|
fclose (ctx->fd);
|
|
return PNGU_CANT_READ_FILE;
|
|
}
|
|
}
|
|
|
|
else
|
|
return PNGU_NO_FILE_SELECTED;;
|
|
|
|
if (png_sig_cmp(magic, 0, 8) != 0)
|
|
{
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
return PNGU_FILE_IS_NOT_PNG;
|
|
}
|
|
|
|
// Allocation of libpng structs
|
|
ctx->png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
|
|
if (!(ctx->png_ptr))
|
|
{
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
ctx->info_ptr = png_create_info_struct (ctx->png_ptr);
|
|
if (!(ctx->info_ptr))
|
|
{
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
png_destroy_read_struct (&(ctx->png_ptr), (png_infopp)NULL, (png_infopp)NULL);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
if (ctx->source == PNGU_SOURCE_BUFFER)
|
|
{
|
|
// Installation of our custom data provider function
|
|
ctx->cursor = 0;
|
|
png_set_read_fn (ctx->png_ptr, ctx, pngu_read_data_from_buffer);
|
|
}
|
|
else if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
{
|
|
// Default data provider uses function fread, so it needs to use our FILE*
|
|
png_init_io (ctx->png_ptr, ctx->fd);
|
|
png_set_sig_bytes (ctx->png_ptr, 8); // We have read 8 bytes already to check PNG authenticity
|
|
}
|
|
|
|
// Read png header
|
|
png_read_info (ctx->png_ptr, ctx->info_ptr);
|
|
|
|
// Query image properties if they have not been queried before
|
|
if (!ctx->propRead)
|
|
{
|
|
int ctxNumTrans;
|
|
|
|
png_get_IHDR(ctx->png_ptr, ctx->info_ptr, &width, &height,
|
|
(int *) &(ctx->prop.imgBitDepth),
|
|
(int *) &(ctx->prop.imgColorType),
|
|
NULL, NULL, NULL);
|
|
|
|
ctx->prop.imgWidth = width;
|
|
ctx->prop.imgHeight = height;
|
|
switch (ctx->prop.imgColorType)
|
|
{
|
|
case PNG_COLOR_TYPE_GRAY:
|
|
ctx->prop.imgColorType = PNGU_COLOR_TYPE_GRAY;
|
|
break;
|
|
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
ctx->prop.imgColorType = PNGU_COLOR_TYPE_GRAY_ALPHA;
|
|
break;
|
|
case PNG_COLOR_TYPE_PALETTE:
|
|
ctx->prop.imgColorType = PNGU_COLOR_TYPE_PALETTE;
|
|
break;
|
|
case PNG_COLOR_TYPE_RGB:
|
|
ctx->prop.imgColorType = PNGU_COLOR_TYPE_RGB;
|
|
break;
|
|
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
ctx->prop.imgColorType = PNGU_COLOR_TYPE_RGB_ALPHA;
|
|
break;
|
|
default:
|
|
ctx->prop.imgColorType = PNGU_COLOR_TYPE_UNKNOWN;
|
|
break;
|
|
}
|
|
|
|
// Constant used to scale 16 bit values to 8 bit values
|
|
scale = 0;
|
|
if (ctx->prop.imgBitDepth == 16)
|
|
scale = 8;
|
|
|
|
// Query background color, if any.
|
|
ctx->prop.validBckgrnd = 0;
|
|
|
|
switch(ctx->prop.imgColorType)
|
|
{
|
|
case PNGU_COLOR_TYPE_RGB:
|
|
case PNGU_COLOR_TYPE_RGB_ALPHA:
|
|
{
|
|
if(png_get_bKGD (ctx->png_ptr, ctx->info_ptr, &background)){
|
|
ctx->prop.validBckgrnd = 1;
|
|
ctx->prop.bckgrnd.r = background->red >> scale;
|
|
ctx->prop.bckgrnd.g = background->green >> scale;
|
|
ctx->prop.bckgrnd.b = background->blue >> scale;
|
|
}
|
|
|
|
// Query list of transparent colors, if any.
|
|
ctx->prop.numTrans = 0;
|
|
ctx->prop.trans = NULL;
|
|
|
|
if(png_get_tRNS (ctx->png_ptr, ctx->info_ptr, &trans, (int *) &(ctx->prop.numTrans), &trans_values)){
|
|
ctxNumTrans = ctx->prop.numTrans;
|
|
if(ctxNumTrans){
|
|
ctx->prop.trans = malloc (sizeof (PNGUCOLOR) * ctxNumTrans);
|
|
if (ctx->prop.trans)
|
|
for (i = 0; i < ctxNumTrans; i++)
|
|
{
|
|
ctx->prop.trans[i].r = trans_values[i].red >> scale;
|
|
ctx->prop.trans[i].g = trans_values[i].green >> scale;
|
|
ctx->prop.trans[i].b = trans_values[i].blue >> scale;
|
|
}
|
|
else
|
|
ctx->prop.numTrans = 0;
|
|
}
|
|
}
|
|
|
|
}
|
|
break;
|
|
|
|
case PNGU_COLOR_TYPE_GRAY:
|
|
case PNGU_COLOR_TYPE_GRAY_ALPHA:
|
|
{
|
|
if(png_get_bKGD (ctx->png_ptr, ctx->info_ptr, &background)){
|
|
ctx->prop.validBckgrnd = 1;
|
|
ctx->prop.bckgrnd.r =
|
|
ctx->prop.bckgrnd.g =
|
|
ctx->prop.bckgrnd.b = background->gray >> scale;
|
|
}
|
|
|
|
// Query list of transparent colors, if any.
|
|
ctx->prop.numTrans = 0;
|
|
ctx->prop.trans = NULL;
|
|
|
|
if(png_get_tRNS (ctx->png_ptr, ctx->info_ptr, &trans, (int *) &(ctx->prop.numTrans), &trans_values)){
|
|
ctxNumTrans = ctx->prop.numTrans;
|
|
if(ctxNumTrans){
|
|
ctx->prop.trans = malloc (sizeof (PNGUCOLOR) * ctxNumTrans);
|
|
if (ctx->prop.trans)
|
|
for (i = 0; i < ctxNumTrans; i++)
|
|
ctx->prop.trans[i].r =
|
|
ctx->prop.trans[i].g =
|
|
ctx->prop.trans[i].b = trans_values[i].gray >> scale;
|
|
else
|
|
ctx->prop.numTrans = 0;
|
|
}
|
|
}
|
|
|
|
}
|
|
break;
|
|
|
|
default:
|
|
|
|
// It was none of those things,
|
|
{
|
|
// Query list of transparent colors, if any.
|
|
ctx->prop.numTrans = 0;
|
|
ctx->prop.trans = NULL;
|
|
}
|
|
break;
|
|
}
|
|
|
|
ctx->propRead = 1;
|
|
}
|
|
|
|
// Success
|
|
ctx->infoRead = 1;
|
|
|
|
return PNGU_OK;
|
|
}
|
|
|
|
int pngu_decode (IMGCTX ctx, PNGU_u32 width, PNGU_u32 height, PNGU_u32 stripAlpha)
|
|
{
|
|
png_uint_32 rowbytes;
|
|
png_uint_32 i, propImgHeight;
|
|
|
|
// Read info if it hasn't been read before
|
|
if (!ctx->infoRead)
|
|
{
|
|
int c = pngu_info (ctx);
|
|
if (c != PNGU_OK)
|
|
return c;
|
|
}
|
|
|
|
// Check if the user has specified the real width and height of the image
|
|
if ( (ctx->prop.imgWidth != width) || (ctx->prop.imgHeight != height) )
|
|
return PNGU_INVALID_WIDTH_OR_HEIGHT;
|
|
|
|
// Check if color type is supported by PNGU
|
|
if ( (ctx->prop.imgColorType == PNGU_COLOR_TYPE_PALETTE) || (ctx->prop.imgColorType == PNGU_COLOR_TYPE_UNKNOWN) )
|
|
return PNGU_UNSUPPORTED_COLOR_TYPE;
|
|
|
|
// Scale 16 bit samples to 8 bit
|
|
if (ctx->prop.imgBitDepth == 16)
|
|
png_set_strip_16 (ctx->png_ptr);
|
|
|
|
// Remove alpha channel if we don't need it
|
|
if (stripAlpha && ((ctx->prop.imgColorType == PNGU_COLOR_TYPE_RGB_ALPHA) || (ctx->prop.imgColorType == PNGU_COLOR_TYPE_GRAY_ALPHA)))
|
|
png_set_strip_alpha (ctx->png_ptr);
|
|
|
|
// Expand 1, 2 and 4 bit samples to 8 bit
|
|
if (ctx->prop.imgBitDepth < 8)
|
|
png_set_packing (ctx->png_ptr);
|
|
|
|
// Transform grayscale images to RGB
|
|
if ( (ctx->prop.imgColorType == PNGU_COLOR_TYPE_GRAY) || (ctx->prop.imgColorType == PNGU_COLOR_TYPE_GRAY_ALPHA) )
|
|
png_set_gray_to_rgb (ctx->png_ptr);
|
|
|
|
// Flush transformations
|
|
png_read_update_info (ctx->png_ptr, ctx->info_ptr);
|
|
|
|
// Allocate memory to store the image
|
|
rowbytes = png_get_rowbytes (ctx->png_ptr, ctx->info_ptr);
|
|
|
|
if (rowbytes & 3)
|
|
rowbytes = ((rowbytes >> 2) + 1) << 2; // Add extra padding so each row starts in a 4 byte boundary
|
|
|
|
ctx->img_data = malloc (rowbytes * ctx->prop.imgHeight);
|
|
if (!ctx->img_data)
|
|
{
|
|
pngu_free_info (ctx);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
ctx->row_pointers = malloc (sizeof (png_bytep) * ctx->prop.imgHeight);
|
|
if (!ctx->row_pointers)
|
|
{
|
|
free (ctx->img_data);
|
|
pngu_free_info (ctx);
|
|
return PNGU_LIB_ERROR;
|
|
}
|
|
|
|
propImgHeight = ctx->prop.imgHeight;
|
|
for (i = 0; i < propImgHeight; ++i)
|
|
ctx->row_pointers[i] = ctx->img_data + (i * rowbytes);
|
|
|
|
// Transform the image and copy it to our allocated memory
|
|
png_read_image (ctx->png_ptr, ctx->row_pointers);
|
|
|
|
// Free resources
|
|
pngu_free_info (ctx);
|
|
|
|
// Success
|
|
return PNGU_OK;
|
|
}
|
|
|
|
void pngu_free_info (IMGCTX ctx)
|
|
{
|
|
if (ctx->infoRead)
|
|
{
|
|
if (ctx->source == PNGU_SOURCE_DEVICE)
|
|
fclose (ctx->fd);
|
|
|
|
png_destroy_read_struct (&(ctx->png_ptr), &(ctx->info_ptr), (png_infopp)NULL);
|
|
|
|
ctx->infoRead = 0;
|
|
}
|
|
}
|
|
|
|
// Custom data provider function used for reading from memory buffers.
|
|
void pngu_read_data_from_buffer (png_structp png_ptr, png_bytep data, png_size_t length)
|
|
{
|
|
IMGCTX ctx = (IMGCTX) png_get_io_ptr (png_ptr);
|
|
memcpy (data, ctx->buffer + ctx->cursor, length);
|
|
ctx->cursor += length;
|
|
}
|
|
|
|
// Custom data writer function used for writing to memory buffers.
|
|
void pngu_write_data_to_buffer (png_structp png_ptr, png_bytep data, png_size_t length)
|
|
{
|
|
IMGCTX ctx = (IMGCTX) png_get_io_ptr (png_ptr);
|
|
memcpy (ctx->buffer + ctx->cursor, data, length);
|
|
ctx->cursor += length;
|
|
}
|
|
|
|
// Custom data flusher function used for writing to memory buffers.
|
|
void pngu_flush_data_to_buffer (png_structp png_ptr)
|
|
{
|
|
// Nothing to do here
|
|
}
|
|
|
|
// Function used in YCbYCr to RGB decoding
|
|
int pngu_clamp (int value, int min, int max)
|
|
{
|
|
if (value < min)
|
|
value = min;
|
|
else if (value > max)
|
|
value = max;
|
|
|
|
return value;
|
|
}
|