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-rw-r--r--progs/samples/rgbtoppm.c273
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;
+}
+