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Aquaria/ExternalLibs/glpng/glpng.c

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/*
* PNG loader library for OpenGL v1.45 (10/07/00)
* by Ben Wyatt ben@wyatt100.freeserve.co.uk
* Using LibPNG 1.0.2 and ZLib 1.1.3
*
* This software is provided 'as-is', without any express or implied warranty.
* In no event will the author be held liable for any damages arising from the
* use of this software.
*
* Permission is hereby granted to use, copy, modify, and distribute this
* source code, or portions hereof, for any purpose, without fee, subject to
* the following restrictions:
*
* 1. The origin of this source code must not be misrepresented. You must not
* claim that you wrote the original software. If you use this software in
* a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered versions must be plainly marked as such and must not be
* misrepresented as being the original source.
* 3. This notice must not be removed or altered from any source distribution.
*/
#ifdef _WIN32 /* Stupid Windows needs to include windows.h before gl.h */
#undef FAR
#include <windows.h>
#endif
#include "../glpng.h"
#include "gl.h"
#include <stdlib.h>
#include <math.h>
#include <png.h>
/* Used to decide if GL/gl.h supports the paletted extension */
#ifdef GL_COLOR_INDEX1_EXT
#define SUPPORTS_PALETTE_EXT
#endif
static unsigned char DefaultAlphaCallback(unsigned char red, unsigned char green, unsigned char blue) {
return 255;
}
static unsigned char StencilRed = 0, StencilGreen = 0, StencilBlue = 0;
static unsigned char (*AlphaCallback)(unsigned char red, unsigned char green, unsigned char blue) = DefaultAlphaCallback;
static int StandardOrientation = 0;
#ifdef SUPPORTS_PALETTE_EXT
#ifdef _WIN32
static PFNGLCOLORTABLEEXTPROC glColorTableEXT = NULL;
#endif
#endif
static int PalettedTextures = -1;
static GLint MaxTextureSize = 0;
/* screenGamma = displayGamma/viewingGamma
* displayGamma = CRT has gamma of ~2.2
* viewingGamma depends on platform. PC is 1.0, Mac is 1.45, SGI defaults
* to 1.7, but this can be checked and changed w/ /usr/sbin/gamma command.
* If the environment variable VIEWING_GAMMA is set, adjust gamma per this value.
*/
#ifdef _MAC
static double screenGamma = 2.2 / 1.45;
#elif SGI
static double screenGamma = 2.2 / 1.7;
#else /* PC/default */
static double screenGamma = 2.2 / 1.0;
#endif
static char gammaExplicit = 0; /*if */
static void checkForGammaEnv()
{
double viewingGamma;
char *gammaEnv = getenv("VIEWING_GAMMA");
if(gammaEnv && !gammaExplicit)
{
sscanf(gammaEnv, "%lf", &viewingGamma);
screenGamma = 2.2/viewingGamma;
}
}
/* Returns a safe texture size to use (ie a power of 2), based on the current texture size "i" */
static int SafeSize(int i) {
int p;
if (i > MaxTextureSize) return MaxTextureSize;
for (p = 0; p < 24; p++)
if (i <= (1<<p))
return 1<<p;
return MaxTextureSize;
}
/* Resize the texture since gluScaleImage doesn't work on everything */
static void Resize(int components, const png_bytep d1, int w1, int h1, png_bytep d2, int w2, int h2) {
const float sx = (float) w1/w2, sy = (float) h1/h2;
int x, y, xx, yy, c;
png_bytep d;
for (y = 0; y < h2; y++) {
yy = (int) (y*sy)*w1;
for (x = 0; x < w2; x++) {
xx = (int) (x*sx);
d = d1 + (yy+xx)*components;
for (c = 0; c < components; c++)
*d2++ = *d++;
}
}
}
static int ExtSupported(const char *x) {
static const GLubyte *ext = NULL;
const char *c;
int xlen = strlen(x);
if (ext == NULL) ext = glGetString(GL_EXTENSIONS);
c = (const char*)ext;
while (*c != '\0') {
if (strcmp(c, x) == 0 && (c[xlen] == '\0' || c[xlen] == ' ')) return 1;
c++;
}
return 0;
}
#define GET(o) ((int)*(data + (o)))
static int HalfSize(GLint components, GLint width, GLint height, const unsigned char *data, unsigned char *d, int filter) {
int x, y, c;
int line = width*components;
if (width > 1 && height > 1) {
if (filter)
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 2) {
for (c = 0; c < components; c++) {
*d++ = (GET(0)+GET(components)+GET(line)+GET(line+components)) / 4;
data++;
}
data += components;
}
data += line;
}
else
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 2) {
for (c = 0; c < components; c++) {
*d++ = GET(0);
data++;
}
data += components;
}
data += line;
}
}
else if (width > 1 && height == 1) {
if (filter)
for (y = 0; y < height; y += 1) {
for (x = 0; x < width; x += 2) {
for (c = 0; c < components; c++) {
*d++ = (GET(0)+GET(components)) / 2;
data++;
}
data += components;
}
}
else
for (y = 0; y < height; y += 1) {
for (x = 0; x < width; x += 2) {
for (c = 0; c < components; c++) {
*d++ = GET(0);
data++;
}
data += components;
}
}
}
else if (width == 1 && height > 1) {
if (filter)
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 1) {
for (c = 0; c < components; c++) {
*d++ = (GET(0)+GET(line)) / 2;
data++;
}
}
data += line;
}
else
for (y = 0; y < height; y += 2) {
for (x = 0; x < width; x += 1) {
for (c = 0; c < components; c++) {
*d++ = GET(0);
data++;
}
}
data += line;
}
}
else {
return 0;
}
return 1;
}
#undef GET
/* Replacement for gluBuild2DMipmaps so GLU isn't needed */
static void Build2DMipmaps(GLint components, GLint width, GLint height, GLenum format, const unsigned char *data, int filter) {
int level = 0;
unsigned char *d = (unsigned char *) malloc((width/2)*(height/2)*components+4);
const unsigned char *last = data;
glTexImage2D(GL_TEXTURE_2D, level, components, width, height, 0, format, GL_UNSIGNED_BYTE, data);
level++;
while (HalfSize(components, width, height, last, d, filter)) {
if (width > 1) width /= 2;
if (height > 1) height /= 2;
glTexImage2D(GL_TEXTURE_2D, level, components, width, height, 0, format, GL_UNSIGNED_BYTE, d);
level++;
last = d;
}
free(d);
}
int APIENTRY pngLoadRaw(const char *filename, pngRawInfo *pinfo) {
int result;
FILE *fp = fopen(filename, "rb");
if (fp == NULL) return 0;
result = pngLoadRawF(fp, pinfo);
if (fclose(fp) != 0) {
if (result) {
free(pinfo->Data);
free(pinfo->Palette);
}
return 0;
}
return result;
}
int APIENTRY pngLoadRawF(FILE *fp, pngRawInfo *pinfo) {
unsigned char header[8];
png_structp png;
png_infop info;
png_infop endinfo;
png_bytep data;
png_bytep *row_p;
double fileGamma;
png_uint_32 width, height;
int depth, color;
png_uint_32 i;
if (pinfo == NULL) return 0;
if (fread(header, 1, 8, fp) != 8) return 0;
if (!png_check_sig(header, 8)) return 0;
png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
info = png_create_info_struct(png);
endinfo = png_create_info_struct(png);
// DH: added following lines
if (setjmp(png_jmpbuf(png)))
{
png_destroy_read_struct(&png, &info, &endinfo);
return 0;
}
// ~DH
png_init_io(png, fp);
png_set_sig_bytes(png, 8);
png_read_info(png, info);
png_get_IHDR(png, info, &width, &height, &depth, &color, NULL, NULL, NULL);
pinfo->Width = width;
pinfo->Height = height;
pinfo->Depth = depth;
/*--GAMMA--*/
checkForGammaEnv();
if (png_get_gAMA(png, info, &fileGamma))
png_set_gamma(png, screenGamma, fileGamma);
else
png_set_gamma(png, screenGamma, 1.0/2.2);
png_read_update_info(png, info);
data = (png_bytep) malloc(png_get_rowbytes(png, info)*height);
row_p = (png_bytep *) malloc(sizeof(png_bytep)*height);
for (i = 0; i < height; i++) {
if (StandardOrientation)
row_p[height - 1 - i] = &data[png_get_rowbytes(png, info)*i];
else
row_p[i] = &data[png_get_rowbytes(png, info)*i];
}
png_read_image(png, row_p);
free(row_p);
if (color == PNG_COLOR_TYPE_PALETTE) {
int cols;
png_get_PLTE(png, info, (png_colorp *) &pinfo->Palette, &cols);
}
else {
pinfo->Palette = NULL;
}
if (color&PNG_COLOR_MASK_ALPHA) {
if (color&PNG_COLOR_MASK_PALETTE || color == PNG_COLOR_TYPE_GRAY_ALPHA)
pinfo->Components = 2;
else
pinfo->Components = 4;
pinfo->Alpha = 8;
}
else {
if (color&PNG_COLOR_MASK_PALETTE || color == PNG_COLOR_TYPE_GRAY)
pinfo->Components = 1;
else
pinfo->Components = 3;
pinfo->Alpha = 0;
}
pinfo->Data = data;
png_read_end(png, endinfo);
png_destroy_read_struct(&png, &info, &endinfo);
return 1;
}
int APIENTRY pngLoad(const char *filename, int mipmap, int trans, pngInfo *pinfo) {
int result;
FILE *fp = fopen(filename, "rb");
if (fp == NULL) return 0;
result = pngLoadF(fp, mipmap, trans, pinfo);
if (fclose(fp) != 0) return 0;
return result;
}
int APIENTRY pngLoadF(FILE *fp, int mipmap, int trans, pngInfo *pinfo) {
GLint pack, unpack;
unsigned char header[8];
png_structp png;
png_infop info;
png_infop endinfo;
png_bytep data, data2;
png_bytep *row_p;
double fileGamma;
png_uint_32 width, height, rw, rh;
int depth, color;
png_uint_32 i;
if (fread(header, 1, 8, fp) != 8) return 0;
if (!png_check_sig(header, 8)) return 0;
png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
info = png_create_info_struct(png);
endinfo = png_create_info_struct(png);
// DH: added following lines
if (setjmp(png_jmpbuf(png)))
{
png_destroy_read_struct(&png, &info, &endinfo);
return 0;
}
// ~DH
png_init_io(png, fp);
png_set_sig_bytes(png, 8);
png_read_info(png, info);
png_get_IHDR(png, info, &width, &height, &depth, &color, NULL, NULL, NULL);
if (pinfo != NULL) {
pinfo->Width = width;
pinfo->Height = height;
pinfo->Depth = depth;
}
if (MaxTextureSize == 0)
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &MaxTextureSize);
#ifdef SUPPORTS_PALETTE_EXT
#ifdef _WIN32
if (PalettedTextures == -1)
PalettedTextures = ExtSupported("GL_EXT_paletted_texture") && (strstr((const char *) glGetString(GL_VERSION), "1.1.0 3Dfx Beta") == NULL);
if (PalettedTextures) {
if (glColorTableEXT == NULL) {
glColorTableEXT = (PFNGLCOLORTABLEEXTPROC) wglGetProcAddress("glColorTableEXT");
if (glColorTableEXT == NULL)
PalettedTextures = 0;
}
}
#endif
#endif
if (PalettedTextures == -1)
PalettedTextures = 0;
if (color == PNG_COLOR_TYPE_GRAY || color == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png);
if (color&PNG_COLOR_MASK_ALPHA && trans != PNG_ALPHA) {
png_set_strip_alpha(png);
color &= ~PNG_COLOR_MASK_ALPHA;
}
if (!(PalettedTextures && mipmap >= 0 && trans == PNG_SOLID))
if (color == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png);
/*--GAMMA--*/
checkForGammaEnv();
if (png_get_gAMA(png, info, &fileGamma))
png_set_gamma(png, screenGamma, fileGamma);
else
png_set_gamma(png, screenGamma, 1.0/2.2);
png_read_update_info(png, info);
data = (png_bytep) malloc(png_get_rowbytes(png, info)*height);
row_p = (png_bytep *) malloc(sizeof(png_bytep)*height);
for (i = 0; i < height; i++) {
if (StandardOrientation)
row_p[height - 1 - i] = &data[png_get_rowbytes(png, info)*i];
else
row_p[i] = &data[png_get_rowbytes(png, info)*i];
}
png_read_image(png, row_p);
free(row_p);
rw = SafeSize(width), rh = SafeSize(height);
if (rw != width || rh != height) {
const int channels = png_get_rowbytes(png, info)/width;
data2 = (png_bytep) malloc(rw*rh*channels);
/* Doesn't work on certain sizes */
/* if (gluScaleImage(glformat, width, height, GL_UNSIGNED_BYTE, data, rw, rh, GL_UNSIGNED_BYTE, data2) != 0)
return 0;
*/
Resize(channels, data, width, height, data2, rw, rh);
width = rw, height = rh;
free(data);
data = data2;
}
{ /* OpenGL stuff */
glGetIntegerv(GL_PACK_ALIGNMENT, &pack);
glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpack);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
#ifdef SUPPORTS_PALETTE_EXT
if (PalettedTextures && mipmap >= 0 && trans == PNG_SOLID && color == PNG_COLOR_TYPE_PALETTE) {
png_colorp pal;
int cols;
GLint intf;
if (pinfo != NULL) pinfo->Alpha = 0;
png_get_PLTE(png, info, &pal, &cols);
switch (cols) {
case 1<<1: intf = GL_COLOR_INDEX1_EXT; break;
case 1<<2: intf = GL_COLOR_INDEX2_EXT; break;
case 1<<4: intf = GL_COLOR_INDEX4_EXT; break;
case 1<<8: intf = GL_COLOR_INDEX8_EXT; break;
case 1<<12: intf = GL_COLOR_INDEX12_EXT; break;
case 1<<16: intf = GL_COLOR_INDEX16_EXT; break;
default:
/*printf("Warning: Colour depth %i not recognised\n", cols);*/
return 0;
}
glColorTableEXT(GL_TEXTURE_2D, GL_RGB8, cols, GL_RGB, GL_UNSIGNED_BYTE, pal);
glTexImage2D(GL_TEXTURE_2D, mipmap, intf, width, height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, data);
}
else
#endif
if (trans == PNG_SOLID || trans == PNG_ALPHA || trans == PNG_LUMINANCEALPHA || color == PNG_COLOR_TYPE_RGB_ALPHA || color == PNG_COLOR_TYPE_GRAY_ALPHA) {
GLenum glformat;
GLint glcomponent;
switch (color) {
case PNG_COLOR_TYPE_GRAY:
case PNG_COLOR_TYPE_RGB:
case PNG_COLOR_TYPE_PALETTE:
glformat = GL_RGB;
glcomponent = 3;
if (pinfo != NULL) pinfo->Alpha = 0;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
case PNG_COLOR_TYPE_RGB_ALPHA:
glformat = GL_RGBA;
glcomponent = 4;
if (pinfo != NULL) pinfo->Alpha = 8;
break;
default:
/*puts("glformat not set");*/
return 0;
}
if (trans == PNG_LUMINANCEALPHA)
glformat = GL_LUMINANCE_ALPHA;
if (mipmap == PNG_BUILDMIPMAPS)
Build2DMipmaps(glcomponent, width, height, glformat, data, 1);
else if (mipmap == PNG_SIMPLEMIPMAPS)
Build2DMipmaps(glcomponent, width, height, glformat, data, 0);
else
glTexImage2D(GL_TEXTURE_2D, mipmap, glcomponent, width, height, 0, glformat, GL_UNSIGNED_BYTE, data);
}
else {
png_bytep p, endp, q;
int r, g, b, a;
p = data, endp = p+width*height*3;
q = data2 = (png_bytep) malloc(sizeof(png_byte)*width*height*4);
if (pinfo != NULL) pinfo->Alpha = 8;
#define FORSTART \
do { \
r = *p++; /*red */ \
g = *p++; /*green*/ \
b = *p++; /*blue */ \
*q++ = r; \
*q++ = g; \
*q++ = b;
#define FOREND \
q++; \
} while (p != endp);
#define ALPHA *q
switch (trans) {
case PNG_CALLBACKT:
FORSTART
ALPHA = AlphaCallback((unsigned char) r, (unsigned char) g, (unsigned char) b);
FOREND
break;
case PNG_STENCIL:
FORSTART
if (r == StencilRed && g == StencilGreen && b == StencilBlue)
ALPHA = 0;
else
ALPHA = 255;
FOREND
break;
case PNG_BLEND1:
FORSTART
a = r+g+b;
if (a > 255) ALPHA = 255; else ALPHA = a;
FOREND
break;
case PNG_BLEND2:
FORSTART
a = r+g+b;
if (a > 255*2) ALPHA = 255; else ALPHA = a/2;
FOREND
break;
case PNG_BLEND3:
FORSTART
ALPHA = (r+g+b)/3;
FOREND
break;
case PNG_BLEND4:
FORSTART
a = r*r+g*g+b*b;
if (a > 255) ALPHA = 255; else ALPHA = a;
FOREND
break;
case PNG_BLEND5:
FORSTART
a = r*r+g*g+b*b;
if (a > 255*2) ALPHA = 255; else ALPHA = a/2;
FOREND
break;
case PNG_BLEND6:
FORSTART
a = r*r+g*g+b*b;
if (a > 255*3) ALPHA = 255; else ALPHA = a/3;
FOREND
break;
case PNG_BLEND7:
FORSTART
a = r*r+g*g+b*b;
if (a > 255*255) ALPHA = 255; else ALPHA = (int) sqrt(a);
FOREND
break;
}
#undef FORSTART
#undef FOREND
#undef ALPHA
if (mipmap == PNG_BUILDMIPMAPS)
Build2DMipmaps(4, width, height, GL_RGBA, data2, 1);
else if (mipmap == PNG_SIMPLEMIPMAPS)
Build2DMipmaps(4, width, height, GL_RGBA, data2, 0);
else
glTexImage2D(GL_TEXTURE_2D, mipmap, 4, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data2);
free(data2);
}
glPixelStorei(GL_PACK_ALIGNMENT, pack);
glPixelStorei(GL_UNPACK_ALIGNMENT, unpack);
} /* OpenGL end */
png_read_end(png, endinfo);
png_destroy_read_struct(&png, &info, &endinfo);
free(data);
return 1;
}
static unsigned int SetParams(int wrapst, int magfilter, int minfilter) {
GLuint id;
glGenTextures(1, &id);
glBindTexture(GL_TEXTURE_2D, id);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapst);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapst);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magfilter);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minfilter);
return id;
}
unsigned int APIENTRY pngBind(const char *filename, int mipmap, int trans, pngInfo *info, int wrapst, int minfilter, int magfilter) {
unsigned int id = SetParams(wrapst, magfilter, minfilter);
if (id != 0 && pngLoad(filename, mipmap, trans, info))
return id;
return 0;
}
unsigned int APIENTRY pngBindF(FILE *file, int mipmap, int trans, pngInfo *info, int wrapst, int minfilter, int magfilter) {
unsigned int id = SetParams(wrapst, magfilter, minfilter);
if (id != 0 && pngLoadF(file, mipmap, trans, info))
return id;
return 0;
}
unsigned int APIENTRY pngBindMem(const char *mem, int size, int mipmap, int trans, pngInfo *info, int wrapst, int minfilter, int magfilter) {
unsigned int id = SetParams(wrapst, magfilter, minfilter);
if (id != 0 && pngLoadMem(mem, size, mipmap, trans, info))
return id;
return 0;
}
void APIENTRY pngSetStencil(unsigned char red, unsigned char green, unsigned char blue) {
StencilRed = red, StencilGreen = green, StencilBlue = blue;
}
void APIENTRY pngSetAlphaCallback(unsigned char (*callback)(unsigned char red, unsigned char green, unsigned char blue)) {
if (callback == NULL)
AlphaCallback = DefaultAlphaCallback;
else
AlphaCallback = callback;
}
void APIENTRY pngSetViewingGamma(double viewingGamma) {
if(viewingGamma > 0) {
gammaExplicit = 1;
screenGamma = 2.2/viewingGamma;
}
else {
gammaExplicit = 0;
screenGamma = 2.2;
}
}
void APIENTRY pngSetStandardOrientation(int standardorientation) {
StandardOrientation = standardorientation;
}
// -- added memory read functions --
/*pointer to a new input function that takes as its
arguments a pointer to a png_struct, a pointer to
a location where input data can be stored, and a 32-bit
unsigned int that is the number of bytes to be read.
To exit and output any fatal error messages the new write
function should call png_error(png_ptr, "Error msg"). */
typedef struct glpng_memread_struct
{
png_bytep mem;
png_size_t rpos;
} glpng_memread;
void glpng_read_mem(png_structp png, png_bytep dst, png_size_t size)
{
glpng_memread *mr = (glpng_memread*)png_get_io_ptr(png);
memcpy(dst, mr->mem + mr->rpos, size);
mr->rpos += size;
}
int APIENTRY pngLoadMem(const char *mem, int size, int mipmap, int trans, pngInfo *pinfo) {
GLint pack, unpack;
unsigned char header[8];
png_structp png;
png_infop info;
png_infop endinfo;
png_bytep data, data2;
png_bytep *row_p;
double fileGamma;
png_uint_32 width, height, rw, rh;
int depth, color;
png_uint_32 i;
glpng_memread memread;
if(size < 8)
return 0; // error
memcpy(header, mem, 8);
if (!png_check_sig(header, 8))
return 0;
png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
info = png_create_info_struct(png);
endinfo = png_create_info_struct(png);
// DH: added following lines
if (setjmp(png_jmpbuf(png)))
{
png_destroy_read_struct(&png, &info, &endinfo);
return 0;
}
// ~DH
memread.rpos = 0;
memread.mem = ((png_bytep)mem) + 8;
png_set_read_fn(png, &memread, glpng_read_mem);
png_set_sig_bytes(png, 8);
png_read_info(png, info);
png_get_IHDR(png, info, &width, &height, &depth, &color, NULL, NULL, NULL);
if (pinfo != NULL) {
pinfo->Width = width;
pinfo->Height = height;
pinfo->Depth = depth;
}
if (MaxTextureSize == 0)
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &MaxTextureSize);
#ifdef SUPPORTS_PALETTE_EXT
#ifdef _WIN32
if (PalettedTextures == -1)
PalettedTextures = ExtSupported("GL_EXT_paletted_texture") && (strstr((const char *) glGetString(GL_VERSION), "1.1.0 3Dfx Beta") == NULL);
if (PalettedTextures) {
if (glColorTableEXT == NULL) {
glColorTableEXT = (PFNGLCOLORTABLEEXTPROC) wglGetProcAddress("glColorTableEXT");
if (glColorTableEXT == NULL)
PalettedTextures = 0;
}
}
#endif
#endif
if (PalettedTextures == -1)
PalettedTextures = 0;
if (color == PNG_COLOR_TYPE_GRAY || color == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png);
if (color&PNG_COLOR_MASK_ALPHA && trans != PNG_ALPHA) {
png_set_strip_alpha(png);
color &= ~PNG_COLOR_MASK_ALPHA;
}
if (!(PalettedTextures && mipmap >= 0 && trans == PNG_SOLID))
if (color == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png);
/*--GAMMA--*/
checkForGammaEnv();
if (png_get_gAMA(png, info, &fileGamma))
png_set_gamma(png, screenGamma, fileGamma);
else
png_set_gamma(png, screenGamma, 1.0/2.2);
png_read_update_info(png, info);
data = (png_bytep) malloc(png_get_rowbytes(png, info)*height);
row_p = (png_bytep *) malloc(sizeof(png_bytep)*height);
for (i = 0; i < height; i++) {
if (StandardOrientation)
row_p[height - 1 - i] = &data[png_get_rowbytes(png, info)*i];
else
row_p[i] = &data[png_get_rowbytes(png, info)*i];
}
png_read_image(png, row_p);
free(row_p);
rw = SafeSize(width), rh = SafeSize(height);
if (rw != width || rh != height) {
const int channels = png_get_rowbytes(png, info)/width;
data2 = (png_bytep) malloc(rw*rh*channels);
/* Doesn't work on certain sizes */
/* if (gluScaleImage(glformat, width, height, GL_UNSIGNED_BYTE, data, rw, rh, GL_UNSIGNED_BYTE, data2) != 0)
return 0;
*/
Resize(channels, data, width, height, data2, rw, rh);
width = rw, height = rh;
free(data);
data = data2;
}
{ /* OpenGL stuff */
glGetIntegerv(GL_PACK_ALIGNMENT, &pack);
glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpack);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
#ifdef SUPPORTS_PALETTE_EXT
if (PalettedTextures && mipmap >= 0 && trans == PNG_SOLID && color == PNG_COLOR_TYPE_PALETTE) {
png_colorp pal;
int cols;
GLint intf;
if (pinfo != NULL) pinfo->Alpha = 0;
png_get_PLTE(png, info, &pal, &cols);
switch (cols) {
case 1<<1: intf = GL_COLOR_INDEX1_EXT; break;
case 1<<2: intf = GL_COLOR_INDEX2_EXT; break;
case 1<<4: intf = GL_COLOR_INDEX4_EXT; break;
case 1<<8: intf = GL_COLOR_INDEX8_EXT; break;
case 1<<12: intf = GL_COLOR_INDEX12_EXT; break;
case 1<<16: intf = GL_COLOR_INDEX16_EXT; break;
default:
/*printf("Warning: Colour depth %i not recognised\n", cols);*/
return 0;
}
glColorTableEXT(GL_TEXTURE_2D, GL_RGB8, cols, GL_RGB, GL_UNSIGNED_BYTE, pal);
glTexImage2D(GL_TEXTURE_2D, mipmap, intf, width, height, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, data);
}
else
#endif
if (trans == PNG_SOLID || trans == PNG_ALPHA || trans == PNG_LUMINANCEALPHA || color == PNG_COLOR_TYPE_RGB_ALPHA || color == PNG_COLOR_TYPE_GRAY_ALPHA) {
GLenum glformat;
GLint glcomponent;
switch (color) {
case PNG_COLOR_TYPE_GRAY:
case PNG_COLOR_TYPE_RGB:
case PNG_COLOR_TYPE_PALETTE:
glformat = GL_RGB;
glcomponent = 3;
if (pinfo != NULL) pinfo->Alpha = 0;
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
case PNG_COLOR_TYPE_RGB_ALPHA:
glformat = GL_RGBA;
glcomponent = 4;
if (pinfo != NULL) pinfo->Alpha = 8;
break;
default:
/*puts("glformat not set");*/
return 0;
}
if (trans == PNG_LUMINANCEALPHA)
glformat = GL_LUMINANCE_ALPHA;
if (mipmap == PNG_BUILDMIPMAPS)
Build2DMipmaps(glcomponent, width, height, glformat, data, 1);
else if (mipmap == PNG_SIMPLEMIPMAPS)
Build2DMipmaps(glcomponent, width, height, glformat, data, 0);
else
glTexImage2D(GL_TEXTURE_2D, mipmap, glcomponent, width, height, 0, glformat, GL_UNSIGNED_BYTE, data);
}
else {
png_bytep p, endp, q;
int r, g, b, a;
p = data, endp = p+width*height*3;
q = data2 = (png_bytep) malloc(sizeof(png_byte)*width*height*4);
if (pinfo != NULL) pinfo->Alpha = 8;
#define FORSTART \
do { \
r = *p++; /*red */ \
g = *p++; /*green*/ \
b = *p++; /*blue */ \
*q++ = r; \
*q++ = g; \
*q++ = b;
#define FOREND \
q++; \
} while (p != endp);
#define ALPHA *q
switch (trans) {
case PNG_CALLBACKT:
FORSTART
ALPHA = AlphaCallback((unsigned char) r, (unsigned char) g, (unsigned char) b);
FOREND
break;
case PNG_STENCIL:
FORSTART
if (r == StencilRed && g == StencilGreen && b == StencilBlue)
ALPHA = 0;
else
ALPHA = 255;
FOREND
break;
case PNG_BLEND1:
FORSTART
a = r+g+b;
if (a > 255) ALPHA = 255; else ALPHA = a;
FOREND
break;
case PNG_BLEND2:
FORSTART
a = r+g+b;
if (a > 255*2) ALPHA = 255; else ALPHA = a/2;
FOREND
break;
case PNG_BLEND3:
FORSTART
ALPHA = (r+g+b)/3;
FOREND
break;
case PNG_BLEND4:
FORSTART
a = r*r+g*g+b*b;
if (a > 255) ALPHA = 255; else ALPHA = a;
FOREND
break;
case PNG_BLEND5:
FORSTART
a = r*r+g*g+b*b;
if (a > 255*2) ALPHA = 255; else ALPHA = a/2;
FOREND
break;
case PNG_BLEND6:
FORSTART
a = r*r+g*g+b*b;
if (a > 255*3) ALPHA = 255; else ALPHA = a/3;
FOREND
break;
case PNG_BLEND7:
FORSTART
a = r*r+g*g+b*b;
if (a > 255*255) ALPHA = 255; else ALPHA = (int) sqrt(a);
FOREND
break;
}
#undef FORSTART
#undef FOREND
#undef ALPHA
if (mipmap == PNG_BUILDMIPMAPS)
Build2DMipmaps(4, width, height, GL_RGBA, data2, 1);
else if (mipmap == PNG_SIMPLEMIPMAPS)
Build2DMipmaps(4, width, height, GL_RGBA, data2, 0);
else
glTexImage2D(GL_TEXTURE_2D, mipmap, 4, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data2);
free(data2);
}
glPixelStorei(GL_PACK_ALIGNMENT, pack);
glPixelStorei(GL_UNPACK_ALIGNMENT, unpack);
} /* OpenGL end */
png_read_end(png, endinfo);
png_destroy_read_struct(&png, &info, &endinfo);
free(data);
return 1;
}
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