diff options
Diffstat (limited to 'progs/samples/readtex.c')
| -rw-r--r-- | progs/samples/readtex.c | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/progs/samples/readtex.c b/progs/samples/readtex.c new file mode 100644 index 00000000000..37d5fcd0d3a --- /dev/null +++ b/progs/samples/readtex.c @@ -0,0 +1,454 @@ +/* readtex.c */ + +/* + * Read an SGI .rgb image file and generate a mipmap texture set. + * Much of this code was borrowed from SGI's tk OpenGL toolkit. + */ + + + +#include <GL/gl.h> +#include <GL/glu.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "readtex.h" + + +#ifndef SEEK_SET +# define SEEK_SET 0 +#endif + + +/* +** RGB Image Structure +*/ + +typedef struct _TK_RGBImageRec { + GLint sizeX, sizeY; + GLint components; + unsigned char *data; +} TK_RGBImageRec; + + + +/******************************************************************************/ + +typedef struct _rawImageRec { + unsigned short imagic; + unsigned short type; + unsigned short dim; + unsigned short sizeX, sizeY, sizeZ; + unsigned long min, max; + unsigned long wasteBytes; + char name[80]; + unsigned long colorMap; + FILE *file; + unsigned char *tmp, *tmpR, *tmpG, *tmpB, *tmpA; + unsigned long rleEnd; + GLuint *rowStart; + GLint *rowSize; +} rawImageRec; + +/******************************************************************************/ + +static void ConvertShort(unsigned short *array, long length) +{ + unsigned long b1, b2; + unsigned char *ptr; + + ptr = (unsigned char *)array; + while (length--) { + b1 = *ptr++; + b2 = *ptr++; + *array++ = (unsigned short) ((b1 << 8) | (b2)); + } +} + +static void ConvertLong(GLuint *array, long length) +{ + unsigned long b1, b2, b3, b4; + unsigned char *ptr; + + ptr = (unsigned char *)array; + while (length--) { + b1 = *ptr++; + b2 = *ptr++; + b3 = *ptr++; + b4 = *ptr++; + *array++ = (b1 << 24) | (b2 << 16) | (b3 << 8) | (b4); + } +} + +static rawImageRec *RawImageOpen(const char *fileName) +{ + union { + int testWord; + char testByte[4]; + } endianTest; + rawImageRec *raw; + GLenum swapFlag; + int x; + + endianTest.testWord = 1; + if (endianTest.testByte[0] == 1) { + swapFlag = GL_TRUE; + } else { + swapFlag = GL_FALSE; + } + + raw = (rawImageRec *)calloc(1, sizeof(rawImageRec)); + if (raw == NULL) { + fprintf(stderr, "Out of memory!\n"); + return NULL; + } + if ((raw->file = fopen(fileName, "rb")) == NULL) { + perror(fileName); + return NULL; + } + + fread(raw, 1, 12, raw->file); + + if (swapFlag) { + ConvertShort(&raw->imagic, 6); + } + + raw->tmp = (unsigned char *)malloc(raw->sizeX*256); + raw->tmpR = (unsigned char *)malloc(raw->sizeX*256); + raw->tmpG = (unsigned char *)malloc(raw->sizeX*256); + raw->tmpB = (unsigned char *)malloc(raw->sizeX*256); + if (raw->sizeZ==4) { + raw->tmpA = (unsigned char *)malloc(raw->sizeX*256); + } + if (raw->tmp == NULL || raw->tmpR == NULL || raw->tmpG == NULL || + raw->tmpB == NULL) { + fprintf(stderr, "Out of memory!\n"); + return NULL; + } + + if ((raw->type & 0xFF00) == 0x0100) { + x = raw->sizeY * raw->sizeZ * sizeof(GLuint); + raw->rowStart = (GLuint *)malloc(x); + raw->rowSize = (GLint *)malloc(x); + if (raw->rowStart == NULL || raw->rowSize == NULL) { + fprintf(stderr, "Out of memory!\n"); + return NULL; + } + raw->rleEnd = 512 + (2 * x); + fseek(raw->file, 512, SEEK_SET); + fread(raw->rowStart, 1, x, raw->file); + fread(raw->rowSize, 1, x, raw->file); + if (swapFlag) { + ConvertLong(raw->rowStart, (long) (x/sizeof(GLuint))); + ConvertLong((GLuint *)raw->rowSize, (long) (x/sizeof(GLint))); + } + } + return raw; +} + +static void RawImageClose(rawImageRec *raw) +{ + fclose(raw->file); + free(raw->tmp); + free(raw->tmpR); + free(raw->tmpG); + free(raw->tmpB); + if (raw->rowStart) + free(raw->rowStart); + if (raw->rowSize) + free(raw->rowSize); + if (raw->sizeZ>3) { + free(raw->tmpA); + } + free(raw); +} + +static void RawImageGetRow(rawImageRec *raw, unsigned char *buf, int y, int z) +{ + unsigned char *iPtr, *oPtr, pixel; + int count, done = 0; + + if ((raw->type & 0xFF00) == 0x0100) { + fseek(raw->file, (long) raw->rowStart[y+z*raw->sizeY], SEEK_SET); + fread(raw->tmp, 1, (unsigned int)raw->rowSize[y+z*raw->sizeY], + raw->file); + + iPtr = raw->tmp; + oPtr = buf; + while (!done) { + pixel = *iPtr++; + count = (int)(pixel & 0x7F); + if (!count) { + done = 1; + return; + } + if (pixel & 0x80) { + while (count--) { + *oPtr++ = *iPtr++; + } + } else { + pixel = *iPtr++; + while (count--) { + *oPtr++ = pixel; + } + } + } + } else { + fseek(raw->file, 512+(y*raw->sizeX)+(z*raw->sizeX*raw->sizeY), + SEEK_SET); + fread(buf, 1, raw->sizeX, raw->file); + } +} + + +static void RawImageGetData(rawImageRec *raw, TK_RGBImageRec *final) +{ + unsigned char *ptr; + int i, j; + + final->data = (unsigned char *)malloc((raw->sizeX+1)*(raw->sizeY+1)*4); + if (final->data == NULL) { + fprintf(stderr, "Out of memory!\n"); + } + + ptr = final->data; + for (i = 0; i < (int)(raw->sizeY); i++) { + RawImageGetRow(raw, raw->tmpR, i, 0); + RawImageGetRow(raw, raw->tmpG, i, 1); + RawImageGetRow(raw, raw->tmpB, i, 2); + if (raw->sizeZ>3) { + RawImageGetRow(raw, raw->tmpA, i, 3); + } + for (j = 0; j < (int)(raw->sizeX); j++) { + *ptr++ = *(raw->tmpR + j); + *ptr++ = *(raw->tmpG + j); + *ptr++ = *(raw->tmpB + j); + if (raw->sizeZ>3) { + *ptr++ = *(raw->tmpA + j); + } + } + } +} + + +static TK_RGBImageRec *tkRGBImageLoad(const char *fileName) +{ + rawImageRec *raw; + TK_RGBImageRec *final; + + raw = RawImageOpen(fileName); + if (!raw) { + fprintf(stderr, "File not found\n"); + return NULL; + } + final = (TK_RGBImageRec *)malloc(sizeof(TK_RGBImageRec)); + if (final == NULL) { + fprintf(stderr, "Out of memory!\n"); + return NULL; + } + final->sizeX = raw->sizeX; + final->sizeY = raw->sizeY; + final->components = raw->sizeZ; + RawImageGetData(raw, final); + RawImageClose(raw); + return final; +} + + +static void FreeImage( TK_RGBImageRec *image ) +{ + free(image->data); + free(image); +} + + +/* + * Load an SGI .rgb file and generate a set of 2-D mipmaps from it. + * Input: imageFile - name of .rgb to read + * intFormat - internal texture format to use, or number of components + * Return: GL_TRUE if success, GL_FALSE if error. + */ +GLboolean LoadRGBMipmaps( const char *imageFile, GLint intFormat ) +{ + GLint w, h; + return LoadRGBMipmaps2( imageFile, GL_TEXTURE_2D, intFormat, &w, &h ); +} + + + +GLboolean LoadRGBMipmaps2( const char *imageFile, GLenum target, + GLint intFormat, GLint *width, GLint *height ) +{ + GLint error; + GLenum format; + TK_RGBImageRec *image; + + image = tkRGBImageLoad( imageFile ); + if (!image) { + return GL_FALSE; + } + + if (image->components==3) { + format = GL_RGB; + } + else if (image->components==4) { + format = GL_RGBA; + } + else { + /* not implemented */ + fprintf(stderr, + "Error in LoadRGBMipmaps %d-component images not implemented\n", + image->components ); + return GL_FALSE; + } + + error = gluBuild2DMipmaps( target, + intFormat, + image->sizeX, image->sizeY, + format, + GL_UNSIGNED_BYTE, + image->data ); + + *width = image->sizeX; + *height = image->sizeY; + + FreeImage(image); + + return error ? GL_FALSE : GL_TRUE; +} + + + +/* + * Load an SGI .rgb file and return a pointer to the image data. + * Input: imageFile - name of .rgb to read + * Output: width - width of image + * height - height of image + * format - format of image (GL_RGB or GL_RGBA) + * Return: pointer to image data or NULL if error + */ +GLubyte *LoadRGBImage( const char *imageFile, GLint *width, GLint *height, + GLenum *format ) +{ + TK_RGBImageRec *image; + GLint bytes; + GLubyte *buffer; + + image = tkRGBImageLoad( imageFile ); + if (!image) { + return NULL; + } + + if (image->components==3) { + *format = GL_RGB; + } + else if (image->components==4) { + *format = GL_RGBA; + } + else { + /* not implemented */ + fprintf(stderr, + "Error in LoadRGBImage %d-component images not implemented\n", + image->components ); + return NULL; + } + + *width = image->sizeX; + *height = image->sizeY; + + bytes = image->sizeX * image->sizeY * image->components; + buffer = (GLubyte *) malloc(bytes); + if (!buffer) + return NULL; + + memcpy( (void *) buffer, (void *) image->data, bytes ); + + FreeImage(image); + + return buffer; +} + +#define CLAMP( X, MIN, MAX ) ( (X)<(MIN) ? (MIN) : ((X)>(MAX) ? (MAX) : (X)) ) + + +static void ConvertRGBtoYUV(GLint w, GLint h, GLint texel_bytes, + const GLubyte *src, + GLushort *dest) +{ + GLint i, j; + + for (i = 0; i < h; i++) { + for (j = 0; j < w; j++) { + const GLfloat r = (src[0]) / 255.0; + const GLfloat g = (src[1]) / 255.0; + const GLfloat b = (src[2]) / 255.0; + GLfloat y, cr, cb; + GLint iy, icr, icb; + + y = r * 65.481 + g * 128.553 + b * 24.966 + 16; + cb = r * -37.797 + g * -74.203 + b * 112.0 + 128; + cr = r * 112.0 + g * -93.786 + b * -18.214 + 128; + /*printf("%f %f %f -> %f %f %f\n", r, g, b, y, cb, cr);*/ + iy = (GLint) CLAMP(y, 0, 254); + icb = (GLint) CLAMP(cb, 0, 254); + icr = (GLint) CLAMP(cr, 0, 254); + + if (j & 1) { + /* odd */ + *dest = (iy << 8) | icr; + } + else { + /* even */ + *dest = (iy << 8) | icb; + } + dest++; + src += texel_bytes; + } + } +} + + +/* + * Load an SGI .rgb file and return a pointer to the image data, converted + * to 422 yuv. + * + * Input: imageFile - name of .rgb to read + * Output: width - width of image + * height - height of image + * Return: pointer to image data or NULL if error + */ +GLushort *LoadYUVImage( const char *imageFile, GLint *width, GLint *height ) +{ + TK_RGBImageRec *image; + GLushort *buffer; + + image = tkRGBImageLoad( imageFile ); + if (!image) { + return NULL; + } + + if (image->components != 3 && image->components !=4 ) { + /* not implemented */ + fprintf(stderr, + "Error in LoadYUVImage %d-component images not implemented\n", + image->components ); + return NULL; + } + + *width = image->sizeX; + *height = image->sizeY; + + buffer = (GLushort *) malloc( image->sizeX * image->sizeY * 2 ); + + if (buffer) + ConvertRGBtoYUV( image->sizeX, + image->sizeY, + image->components, + image->data, + buffer ); + + + FreeImage(image); + return buffer; +} + |