diff options
Diffstat (limited to 'progs/samples/rgbtoppm.c')
| -rw-r--r-- | progs/samples/rgbtoppm.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/progs/samples/rgbtoppm.c b/progs/samples/rgbtoppm.c new file mode 100644 index 0000000000..0bc73487b0 --- /dev/null +++ b/progs/samples/rgbtoppm.c @@ -0,0 +1,273 @@ + +/* texture.c - by David Blythe, SGI */ + +/* texload is a simplistic routine for reading an SGI .rgb image file. */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <GL/glut.h> + +typedef struct _ImageRec { + unsigned short imagic; + unsigned short type; + unsigned short dim; + unsigned short xsize, ysize, zsize; + unsigned int min, max; + unsigned int wasteBytes; + char name[80]; + unsigned long colorMap; + FILE *file; + unsigned char *tmp; + unsigned long rleEnd; + unsigned int *rowStart; + int *rowSize; +} ImageRec; + +void +rgbtorgb(unsigned char *r,unsigned char *g,unsigned char *b,unsigned char *l,int n) { + while(n--) { + l[0] = r[0]; + l[1] = g[0]; + l[2] = b[0]; + l += 3; r++; g++; b++; + } +} + +static void +ConvertShort(unsigned short *array, unsigned int length) { + unsigned short b1, b2; + unsigned char *ptr; + + ptr = (unsigned char *)array; + while (length--) { + b1 = *ptr++; + b2 = *ptr++; + *array++ = (b1 << 8) | (b2); + } +} + +static void +ConvertUint(unsigned *array, unsigned int length) { + unsigned int 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 ImageRec *ImageOpen(char *fileName) +{ + union { + int testWord; + char testByte[4]; + } endianTest; + ImageRec *image; + int swapFlag; + int x; + + endianTest.testWord = 1; + if (endianTest.testByte[0] == 1) { + swapFlag = 1; + } else { + swapFlag = 0; + } + + image = (ImageRec *)malloc(sizeof(ImageRec)); + if (image == NULL) { + fprintf(stderr, "Out of memory!\n"); + exit(1); + } + if ((image->file = fopen(fileName, "rb")) == NULL) { + return NULL; + } + + fread(image, 1, 12, image->file); + + if (swapFlag) { + ConvertShort(&image->imagic, 6); + } + + image->tmp = (unsigned char *)malloc(image->xsize*256); + if (image->tmp == NULL) { + fprintf(stderr, "\nOut of memory!\n"); + exit(1); + } + + if ((image->type & 0xFF00) == 0x0100) { + x = image->ysize * image->zsize * (int) sizeof(unsigned); + image->rowStart = (unsigned *)malloc(x); + image->rowSize = (int *)malloc(x); + if (image->rowStart == NULL || image->rowSize == NULL) { + fprintf(stderr, "\nOut of memory!\n"); + exit(1); + } + image->rleEnd = 512 + (2 * x); + fseek(image->file, 512, SEEK_SET); + fread(image->rowStart, 1, x, image->file); + fread(image->rowSize, 1, x, image->file); + if (swapFlag) { + ConvertUint(image->rowStart, x/(int) sizeof(unsigned)); + ConvertUint((unsigned *)image->rowSize, x/(int) sizeof(int)); + } + } + return image; +} + +static void +ImageClose(ImageRec *image) { + fclose(image->file); + free(image->tmp); + free(image); +} + +static void +ImageGetRow(ImageRec *image, unsigned char *buf, int y, int z) { + unsigned char *iPtr, *oPtr, pixel; + int count; + + if ((image->type & 0xFF00) == 0x0100) { + fseek(image->file, (long) image->rowStart[y+z*image->ysize], SEEK_SET); + fread(image->tmp, 1, (unsigned int)image->rowSize[y+z*image->ysize], + image->file); + + iPtr = image->tmp; + oPtr = buf; + for (;;) { + pixel = *iPtr++; + count = (int)(pixel & 0x7F); + if (!count) { + return; + } + if (pixel & 0x80) { + while (count--) { + *oPtr++ = *iPtr++; + } + } else { + pixel = *iPtr++; + while (count--) { + *oPtr++ = pixel; + } + } + } + } else { + fseek(image->file, 512+(y*image->xsize)+(z*image->xsize*image->ysize), + SEEK_SET); + fread(buf, 1, image->xsize, image->file); + } +} + +GLubyte * +read_alpha_texture(char *name, int *width, int *height) +{ + unsigned char *base, *lptr; + ImageRec *image; + int y; + + image = ImageOpen(name); + if(!image) { + return NULL; + } + + (*width)=image->xsize; + (*height)=image->ysize; + if (image->zsize != 1) { + ImageClose(image); + return NULL; + } + + base = (unsigned char *)malloc(image->xsize*image->ysize*sizeof(unsigned char)); + lptr = base; + for(y=0; y<image->ysize; y++) { + ImageGetRow(image,lptr,y,0); + lptr += image->xsize; + } + ImageClose(image); + + return (unsigned char *) base; +} + +GLubyte * +read_rgb_texture(char *name, int *width, int *height) +{ + unsigned char *base, *ptr; + unsigned char *rbuf, *gbuf, *bbuf, *abuf; + ImageRec *image; + int y; + + image = ImageOpen(name); + + if(!image) + return NULL; + (*width)=image->xsize; + (*height)=image->ysize; + if (image->zsize != 3 && image->zsize != 4) { + ImageClose(image); + return NULL; + } + + base = (unsigned char*)malloc(image->xsize*image->ysize*sizeof(unsigned int)*3); + rbuf = (unsigned char *)malloc(image->xsize*sizeof(unsigned char)); + gbuf = (unsigned char *)malloc(image->xsize*sizeof(unsigned char)); + bbuf = (unsigned char *)malloc(image->xsize*sizeof(unsigned char)); + abuf = (unsigned char *)malloc(image->xsize*sizeof(unsigned char)); + if(!base || !rbuf || !gbuf || !bbuf || !abuf) { + if (base) free(base); + if (rbuf) free(rbuf); + if (gbuf) free(gbuf); + if (bbuf) free(bbuf); + if (abuf) free(abuf); + return NULL; + } + ptr = base; + for(y=0; y<image->ysize; y++) { + if(image->zsize == 4) { + ImageGetRow(image,rbuf,y,0); + ImageGetRow(image,gbuf,y,1); + ImageGetRow(image,bbuf,y,2); + ImageGetRow(image,abuf,y,3); /* Discard. */ + rgbtorgb(rbuf,gbuf,bbuf,ptr,image->xsize); + ptr += (image->xsize * 3); + } else { + ImageGetRow(image,rbuf,y,0); + ImageGetRow(image,gbuf,y,1); + ImageGetRow(image,bbuf,y,2); + rgbtorgb(rbuf,gbuf,bbuf,ptr,image->xsize); + ptr += (image->xsize * 3); + } + } + ImageClose(image); + free(rbuf); + free(gbuf); + free(bbuf); + free(abuf); + + return (GLubyte *) base; +} + +int main(int argc, char **argv) +{ + int width, height; + GLubyte *data; + + if (argc != 2) + { + fprintf(stderr, "usage: %s <filename>\n", argv[0]); + return 1; + } + + data = read_rgb_texture(argv[1], &width, &height); + + printf("P6\n%d %d\n255\n", width, height); + fwrite(data, width * 3, height, stdout); + + return 0; +} + |