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Improve oslLoadImageFilePNG code
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@dogo
dogo committed Jul 21, 2024
1 parent 58dd460 commit b2a770e
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Showing 2 changed files with 239 additions and 267 deletions.
385 changes: 175 additions & 210 deletions src/Special/oslLoadImageFilePNG.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,220 +6,185 @@
#include "../zconf.h"

// Read / Write PNG
void oslPngReadFn(png_structp png_ptr, png_bytep data, png_size_t length) {
VIRTUAL_FILE *f = (VIRTUAL_FILE *)png_get_io_ptr(png_ptr);
VirtualFileRead(data, length, 1, f);
void oslPngReadFn(png_structp png_ptr, png_bytep data, png_size_t length) {
VIRTUAL_FILE *f = (VIRTUAL_FILE *)png_get_io_ptr(png_ptr);
VirtualFileRead(data, length, 1, f);
}

void oslPngFlushFn(png_structp png_ptr) {
void oslPngFlushFn(png_structp png_ptr) {
// No operation
}

OSL_IMAGE *oslLoadImageFilePNG(char *filename, int location, int pixelFormat)
{
const size_t nSigSize=8;
u8 signature[ nSigSize ];
OSL_IMAGE *img = NULL;
VIRTUAL_FILE *f;
//We only keep the location bits
int imgLocation = location & OSL_LOCATION_MASK;
int i;

f = VirtualFileOpen((void*)filename, 0, VF_AUTO, VF_O_READ);
if (!f)
goto error;

if (VirtualFileRead(signature, sizeof(u8), nSigSize, f) == 0)
{
goto error;
}

if (png_check_sig(signature, nSigSize) == 0) // For libPNG < 1.4.4
{
goto error;
}

png_struct * pPngStruct = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL );

if ( pPngStruct == NULL)
{
goto error;
}

png_info * pPngInfo = png_create_info_struct( pPngStruct );

if ( pPngInfo == NULL )
{
png_destroy_read_struct( &pPngStruct, NULL, NULL );
goto error;
}

if ( setjmp( png_jmpbuf(pPngStruct) ) != 0 )
{
png_destroy_read_struct( &pPngStruct, NULL, NULL );
goto error;
}

png_set_read_fn(pPngStruct, f, (png_rw_ptr)oslPngReadFn);
//png_init_io( pPngStruct, &f );
png_set_sig_bytes( pPngStruct, nSigSize );

if (osl_pixelWidth[pixelFormat] <= 8)
png_read_png( pPngStruct, pPngInfo, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_PACKING | /*PNG_TRANSFORM_EXPAND |*/ PNG_TRANSFORM_BGR, NULL );
else
png_read_png( pPngStruct, pPngInfo, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_BGR, NULL );

png_uint_32 width = png_get_image_width(pPngStruct, pPngInfo);
png_uint_32 height = png_get_image_height(pPngStruct, pPngInfo);
png_uint_32 depth = png_get_bit_depth(pPngStruct, pPngInfo);
int color_type = png_get_color_type(pPngStruct, pPngInfo);

png_byte **pRowTable = png_get_rows(pPngStruct, pPngInfo);
unsigned char r=0, g=0, b=0, a=0;

png_colorp palette;
int num_palette;
png_get_PLTE(pPngStruct, pPngInfo, &palette, &num_palette);

int wantedPixelFormat = pixelFormat;

//If we don't have a palette in the PNG but the pixel format requires one, we load the image in 32-bit mode and convert it to paletted later with oslConvertImageTo.
if (!num_palette && osl_pixelWidth[pixelFormat] <= 8) {
pixelFormat = OSL_PF_8888;
img = oslCreateImage(width, height, OSL_IN_RAM, pixelFormat);
}
else
// Otherwise, we create our image normally directly
img = oslCreateImage(width, height, imgLocation, pixelFormat);

if (img)
{
// If there is need for a palette ...
if (osl_pixelWidth[pixelFormat] <= 8) {

img->palette = oslCreatePalette(oslMin(num_palette, 1 << osl_paletteSizes[pixelFormat]), OSL_PF_8888);
if (img->palette) {
//Make sure to not use too much colors!
png_set_PLTE(pPngStruct, pPngInfo, palette, num_palette);

//Suggestion: consider num_trans?
for (i = 0; i < num_palette; i++) {
r = palette[i].red;
g = palette[i].green;
b = palette[i].blue;
a = 0xff;
//Color key?
if (osl_colorKeyEnabled && RGBA(palette[i].red, palette[i].green, palette[i].blue, 0) == (osl_colorKeyValue & 0x00ffffff))
a = 0;
((u32*)img->palette->data)[i] = RGBA(r, g, b, a);
}
oslUncachePalette(img->palette);
}
}

u32 *p_dest4 = (u32*)img->data;
u16 *p_dest2 = (u16*)img->data;
u8 *p_dest1 = (u8*)img->data;
u32 x, y;
int color_per_entry = 8 / depth;
int color_offset, pixel_value = 0;
int mask = (1 << depth) - 1;

for ( y = 0; y < height; ++y )
{
const png_byte * pRow = pRowTable[ y ];

for ( x = 0; x < width; ++x )
{
switch ( color_type )
{
case PNG_COLOR_TYPE_GRAY:
r = g = b = *pRow++;
if ( r == 0 && g == 0 && b == 0 ) a = 0x00;
else a = 0xff;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
r = g = b = *pRow++;
if ( r == 0 && g == 0 && b == 0 ) a = 0x00;
else a = 0xff;
pRow++;
break;
case PNG_COLOR_TYPE_RGB:
b = *pRow++;
g = *pRow++;
r = *pRow++;
if (osl_colorKeyEnabled &&
r == (osl_colorKeyValue&0xff) &&
g == ((osl_colorKeyValue>>8)&0xff) &&
b == ((osl_colorKeyValue>>16)&0xff))
a = 0, r = 0, g = 0, b = 0;
else
a = 0xff;
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
b = *pRow++;
g = *pRow++;
r = *pRow++;
a = *pRow++;
break;

case PNG_COLOR_TYPE_PALETTE:
color_offset = x % color_per_entry;
pixel_value = (*pRow >> (8 - depth * (color_offset + 1))) & mask;
// Last pixel for this byte
if (x % color_per_entry == color_per_entry - 1)
pRow++;
if (img->palette) {
r = (((u32*)img->palette->data)[pixel_value]) & 0xff;
g = ((((u32*)img->palette->data)[pixel_value]) >> 8) & 0xff;
b = ((((u32*)img->palette->data)[pixel_value]) >> 16) & 0xff;
a = ((((u32*)img->palette->data)[pixel_value]) >> 24) & 0xff;
}
else {
b = palette[pixel_value].blue;
g = palette[pixel_value].green;
r = palette[pixel_value].red;
a = 0xff;
}
break;
}

if (pixelFormat == OSL_PF_8888)
p_dest4[x] = RGBA(r,g,b,a);
else if (pixelFormat == OSL_PF_5650)
p_dest2[x] = RGB16(r,g,b);
else if (pixelFormat == OSL_PF_5551)
p_dest2[x] = RGBA15(r,g,b,a);
else if (pixelFormat == OSL_PF_4444)
p_dest2[x] = RGBA12(r,g,b,a);
else if (pixelFormat == OSL_PF_8BIT)
p_dest1[x] = pixel_value;
else if (pixelFormat == OSL_PF_4BIT) {
p_dest1[x >> 1] &= ~(15 << ((x & 1) << 2));
p_dest1[x >> 1] |= (pixel_value & 15) << ((x & 1) << 2);
}
}

p_dest1 += ( img->realSizeX * osl_pixelWidth[pixelFormat]) >> 3;
p_dest2 += ( img->realSizeX );
p_dest4 += ( img->realSizeX );
}

//Finally convert to the paletted format
if (wantedPixelFormat != pixelFormat)
img = oslConvertImageTo(img, imgLocation, wantedPixelFormat);

png_destroy_read_struct( &pPngStruct, &pPngInfo, NULL );

if (oslImageLocationIsSwizzled(location))
oslSwizzleImage(img);

oslUncacheImage(img);
}
OSL_IMAGE *oslLoadImageFilePNG(char *filename, int location, int pixelFormat) {
const size_t nSigSize = 8;
u8 signature[nSigSize];
OSL_IMAGE *img = NULL;
VIRTUAL_FILE *f;
// We only keep the location bits
int imgLocation = location & OSL_LOCATION_MASK;
int i;

f = VirtualFileOpen((void *)filename, 0, VF_AUTO, VF_O_READ);
if (!f) goto error;

if (VirtualFileRead(signature, sizeof(u8), nSigSize, f) == 0) goto error;

if (!png_check_sig(signature, nSigSize)) goto error;

png_structp pPngStruct = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!pPngStruct) goto error;

png_infop pPngInfo = png_create_info_struct(pPngStruct);
if (!pPngInfo) {
png_destroy_read_struct(&pPngStruct, NULL, NULL);
goto error;
}

if (setjmp(png_jmpbuf(pPngStruct))) {
png_destroy_read_struct(&pPngStruct, &pPngInfo, NULL);
goto error;
}

png_set_read_fn(pPngStruct, f, oslPngReadFn);
png_set_sig_bytes(pPngStruct, nSigSize);

if (osl_pixelWidth[pixelFormat] <= 8) {
png_read_png(pPngStruct, pPngInfo, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_PACKING | PNG_TRANSFORM_BGR, NULL);
} else {
png_read_png(pPngStruct, pPngInfo, PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_PACKING | PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_BGR, NULL);
}

png_uint_32 width = png_get_image_width(pPngStruct, pPngInfo);
png_uint_32 height = png_get_image_height(pPngStruct, pPngInfo);
png_uint_32 depth = png_get_bit_depth(pPngStruct, pPngInfo);
int color_type = png_get_color_type(pPngStruct, pPngInfo);

png_byte **pRowTable = png_get_rows(pPngStruct, pPngInfo);
png_colorp palette;
int num_palette;
png_get_PLTE(pPngStruct, pPngInfo, &palette, &num_palette);

int wantedPixelFormat = pixelFormat;

// If we don't have a palette in the PNG but the pixel format requires one,
// we load the image in 32-bit mode and convert it to paletted later with oslConvertImageTo.
if (!num_palette && osl_pixelWidth[pixelFormat] <= 8) {
pixelFormat = OSL_PF_8888;
img = oslCreateImage(width, height, OSL_IN_RAM, pixelFormat);
} else {
// Otherwise, we create our image normally directly
img = oslCreateImage(width, height, imgLocation, pixelFormat);
}

if (img) {
// If there is need for a palette ...
if (osl_pixelWidth[pixelFormat] <= 8) {
img->palette = oslCreatePalette(oslMin(num_palette, 1 << osl_paletteSizes[pixelFormat]), OSL_PF_8888);
if (img->palette) {
// Suggestion: consider num_trans?
for (i = 0; i < num_palette; i++) {
unsigned char r = palette[i].red;
unsigned char g = palette[i].green;
unsigned char b = palette[i].blue;
unsigned char a = 0xff;
//Color key?
if (osl_colorKeyEnabled && RGBA(r, g, b, 0) == (osl_colorKeyValue & 0x00ffffff)) a = 0;
((u32 *)img->palette->data)[i] = RGBA(r, g, b, a);
}
oslUncachePalette(img->palette);
}
}

u32 *p_dest4 = (u32 *)img->data;
u16 *p_dest2 = (u16 *)img->data;
u8 *p_dest1 = (u8 *)img->data;
int color_per_entry = 8 / depth;
int mask = (1 << depth) - 1;

for (u32 y = 0; y < height; ++y) {
const png_byte *pRow = pRowTable[y];
for (u32 x = 0; x < width; ++x) {
unsigned char r = 0, g = 0, b = 0, a = 0xff;
int pixel_value = 0;

switch (color_type) {
case PNG_COLOR_TYPE_GRAY:
r = g = b = *pRow++;
if (!r && !g && !b) a = 0x00;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
r = g = b = *pRow++;
if (!r && !g && !b) a = 0x00;
pRow++;
break;
case PNG_COLOR_TYPE_RGB:
b = *pRow++;
g = *pRow++;
r = *pRow++;
if (osl_colorKeyEnabled && r == (osl_colorKeyValue & 0xff) && g == ((osl_colorKeyValue >> 8) & 0xff) && b == ((osl_colorKeyValue >> 16) & 0xff)) {
a = r = g = b = 0;
}
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
b = *pRow++;
g = *pRow++;
r = *pRow++;
a = *pRow++;
break;
case PNG_COLOR_TYPE_PALETTE:
pixel_value = (*pRow >> (8 - depth * ((x % color_per_entry) + 1))) & mask;
// Last pixel for this byte
if (x % color_per_entry == color_per_entry - 1) pRow++;
if (img->palette) {
r = ((u32 *)img->palette->data)[pixel_value] & 0xff;
g = (((u32 *)img->palette->data)[pixel_value] >> 8) & 0xff;
b = (((u32 *)img->palette->data)[pixel_value] >> 16) & 0xff;
a = (((u32 *)img->palette->data)[pixel_value] >> 24) & 0xff;
} else {
b = palette[pixel_value].blue;
g = palette[pixel_value].green;
r = palette[pixel_value].red;
}
break;
}

if (pixelFormat == OSL_PF_8888) {
p_dest4[x] = RGBA(r, g, b, a);
} else if (pixelFormat == OSL_PF_5650) {
p_dest2[x] = RGB16(r, g, b);
} else if (pixelFormat == OSL_PF_5551) {
p_dest2[x] = RGBA15(r, g, b, a);
} else if (pixelFormat == OSL_PF_4444) {
p_dest2[x] = RGBA12(r, g, b, a);
} else if (pixelFormat == OSL_PF_8BIT) {
p_dest1[x] = pixel_value;
} else if (pixelFormat == OSL_PF_4BIT) {
p_dest1[x >> 1] &= ~(15 << ((x & 1) << 2));
p_dest1[x >> 1] |= (pixel_value & 15) << ((x & 1) << 2);
}
}

p_dest1 += (img->realSizeX * osl_pixelWidth[pixelFormat]) >> 3;
p_dest2 += img->realSizeX;
p_dest4 += img->realSizeX;
}

// Finally convert to the paletted format
if (wantedPixelFormat != pixelFormat) {
img = oslConvertImageTo(img, imgLocation, wantedPixelFormat);
}

png_destroy_read_struct(&pPngStruct, &pPngInfo, NULL);

if (oslImageLocationIsSwizzled(location)) {
oslSwizzleImage(img);
}

oslUncacheImage(img);
}

error:
if (f)
VirtualFileClose(f);
if (!img)
oslHandleLoadNoFailError(filename);
return img;
if (f) VirtualFileClose(f);
if (!img) oslHandleLoadNoFailError(filename);
return img;
}
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