Initial revision
diff --git a/progs/samples/stretch.c b/progs/samples/stretch.c
new file mode 100644
index 0000000..3f610e7
--- /dev/null
+++ b/progs/samples/stretch.c
@@ -0,0 +1,375 @@
+/*
+ * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that (i) the above copyright notices and this permission notice appear in
+ * all copies of the software and related documentation, and (ii) the name of
+ * Silicon Graphics may not be used in any advertising or
+ * publicity relating to the software without the specific, prior written
+ * permission of Silicon Graphics.
+ *
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
+ * ANY KIND,
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
+ * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
+ * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <GL/glut.h>
+
+
+#define STEPCOUNT 40
+#define FALSE 0
+#define TRUE 1
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+
+
+enum {
+ OP_NOOP = 0,
+ OP_STRETCH,
+ OP_DRAWPOINT,
+ OP_DRAWIMAGE
+};
+
+
+typedef struct _cRec {
+ float x, y;
+} cRec;
+
+typedef struct _vertexRec {
+ float x, y;
+ float dX, dY;
+ float tX, tY;
+} vertexRec;
+
+
+#include "loadppm.c"
+
+GLenum doubleBuffer;
+int imageSizeX, imageSizeY;
+char *fileName = 0;
+PPMImage *image;
+cRec cList[50];
+vertexRec vList[5];
+int cCount, cIndex[2], cStep;
+GLenum op = OP_NOOP;
+
+
+void DrawImage(void)
+{
+
+ glRasterPos2i(0, 0);
+ glDrawPixels(image->sizeX, image->sizeY, GL_RGB, GL_UNSIGNED_BYTE,
+ image->data);
+
+ glFlush();
+ if (doubleBuffer) {
+ glutSwapBuffers();
+ }
+
+ glRasterPos2i(0, 0);
+ glDrawPixels(image->sizeX, image->sizeY, GL_RGB, GL_UNSIGNED_BYTE,
+ image->data);
+}
+
+void DrawPoint(void)
+{
+ int i;
+
+ glColor3f(1.0, 0.0, 1.0);
+ glPointSize(3.0);
+ glBegin(GL_POINTS);
+ for (i = 0; i < cCount; i++) {
+ glVertex2f(cList[i].x, cList[i].y);
+ }
+ glEnd();
+
+ glFlush();
+ if (doubleBuffer) {
+ glutSwapBuffers();
+ }
+}
+
+void InitVList(void)
+{
+
+ vList[0].x = 0.0;
+ vList[0].y = 0.0;
+ vList[0].dX = 0.0;
+ vList[0].dY = 0.0;
+ vList[0].tX = 0.0;
+ vList[0].tY = 0.0;
+
+ vList[1].x = (float)imageSizeX;
+ vList[1].y = 0.0;
+ vList[1].dX = 0.0;
+ vList[1].dY = 0.0;
+ vList[1].tX = 1.0;
+ vList[1].tY = 0.0;
+
+ vList[2].x = (float)imageSizeX;
+ vList[2].y = (float)imageSizeY;
+ vList[2].dX = 0.0;
+ vList[2].dY = 0.0;
+ vList[2].tX = 1.0;
+ vList[2].tY = 1.0;
+
+ vList[3].x = 0.0;
+ vList[3].y = (float)imageSizeY;
+ vList[3].dX = 0.0;
+ vList[3].dY = 0.0;
+ vList[3].tX = 0.0;
+ vList[3].tY = 1.0;
+
+ vList[4].x = cList[0].x;
+ vList[4].y = cList[0].y;
+ vList[4].dX = (cList[1].x - cList[0].x) / STEPCOUNT;
+ vList[4].dY = (cList[1].y - cList[0].y) / STEPCOUNT;
+ vList[4].tX = cList[0].x / (float)imageSizeX;
+ vList[4].tY = cList[0].y / (float)imageSizeY;
+}
+
+void ScaleImage(int sizeX, int sizeY)
+{
+ GLubyte *buf;
+
+ buf = (GLubyte *)malloc(3*sizeX*sizeY);
+ gluScaleImage(GL_RGB, image->sizeX, image->sizeY, GL_UNSIGNED_BYTE,
+ image->data, sizeX, sizeY, GL_UNSIGNED_BYTE, buf);
+ free(image->data);
+ image->data = buf;
+ image->sizeX = sizeX;
+ image->sizeY = sizeY;
+}
+
+void SetPoint(int x, int y)
+{
+
+ cList[cCount].x = (float)x;
+ cList[cCount].y = (float)y;
+ cCount++;
+}
+
+void Stretch(void)
+{
+
+ glBegin(GL_TRIANGLES);
+ glTexCoord2f(vList[0].tX, vList[0].tY);
+ glVertex2f(vList[0].x, vList[0].y);
+ glTexCoord2f(vList[1].tX, vList[1].tY);
+ glVertex2f(vList[1].x, vList[1].y);
+ glTexCoord2f(vList[4].tX, vList[4].tY);
+ glVertex2f(vList[4].x, vList[4].y);
+ glEnd();
+
+ glBegin(GL_TRIANGLES);
+ glTexCoord2f(vList[1].tX, vList[1].tY);
+ glVertex2f(vList[1].x, vList[1].y);
+ glTexCoord2f(vList[2].tX, vList[2].tY);
+ glVertex2f(vList[2].x, vList[2].y);
+ glTexCoord2f(vList[4].tX, vList[4].tY);
+ glVertex2f(vList[4].x, vList[4].y);
+ glEnd();
+
+ glBegin(GL_TRIANGLES);
+ glTexCoord2f(vList[2].tX, vList[2].tY);
+ glVertex2f(vList[2].x, vList[2].y);
+ glTexCoord2f(vList[3].tX, vList[3].tY);
+ glVertex2f(vList[3].x, vList[3].y);
+ glTexCoord2f(vList[4].tX, vList[4].tY);
+ glVertex2f(vList[4].x, vList[4].y);
+ glEnd();
+
+ glBegin(GL_TRIANGLES);
+ glTexCoord2f(vList[3].tX, vList[3].tY);
+ glVertex2f(vList[3].x, vList[3].y);
+ glTexCoord2f(vList[0].tX, vList[0].tY);
+ glVertex2f(vList[0].x, vList[0].y);
+ glTexCoord2f(vList[4].tX, vList[4].tY);
+ glVertex2f(vList[4].x, vList[4].y);
+ glEnd();
+
+ glFlush();
+ if (doubleBuffer) {
+ glutSwapBuffers();
+ }
+
+ if (++cStep < STEPCOUNT) {
+ vList[4].x += vList[4].dX;
+ vList[4].y += vList[4].dY;
+ } else {
+ cIndex[0] = cIndex[1];
+ cIndex[1] = cIndex[1] + 1;
+ if (cIndex[1] == cCount) {
+ cIndex[1] = 0;
+ }
+ vList[4].dX = (cList[cIndex[1]].x - cList[cIndex[0]].x) / STEPCOUNT;
+ vList[4].dY = (cList[cIndex[1]].y - cList[cIndex[0]].y) / STEPCOUNT;
+ cStep = 0;
+ }
+}
+
+void Key(unsigned char key, int x, int y)
+{
+
+ switch (key) {
+ case 27:
+ free(image->data);
+ exit(1);
+ case 32:
+ if (cCount > 1) {
+ InitVList();
+ cIndex[0] = 0;
+ cIndex[1] = 1;
+ cStep = 0;
+ glEnable(GL_TEXTURE_2D);
+ op = OP_STRETCH;
+ }
+ break;
+ default:
+ return;
+ }
+
+ glutPostRedisplay();
+}
+
+void Mouse(int button, int state, int mouseX, int mouseY)
+{
+
+ if (state != GLUT_DOWN)
+ return;
+
+ if (op == OP_STRETCH) {
+ glDisable(GL_TEXTURE_2D);
+ cCount = 0;
+ op = OP_DRAWIMAGE;
+ } else {
+ SetPoint(mouseX, imageSizeY-mouseY);
+ op = OP_DRAWPOINT;
+ }
+
+ glutPostRedisplay();
+}
+
+void Animate(void)
+{
+
+ switch (op) {
+ case OP_STRETCH:
+ Stretch();
+ break;
+ case OP_DRAWPOINT:
+ DrawPoint();
+ break;
+ case OP_DRAWIMAGE:
+ DrawImage();
+ break;
+ default:
+ break;
+ }
+}
+
+static GLenum Args(int argc, char **argv)
+{
+ GLint i;
+
+ doubleBuffer = GL_FALSE;
+
+ for (i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "-sb") == 0) {
+ doubleBuffer = GL_FALSE;
+ } else if (strcmp(argv[i], "-db") == 0) {
+ doubleBuffer = GL_TRUE;
+ } else if (strcmp(argv[i], "-f") == 0) {
+ if (i+1 >= argc || argv[i+1][0] == '-') {
+ printf("-f (No file name).\n");
+ return GL_FALSE;
+ } else {
+ fileName = argv[++i];
+ }
+ } else {
+ printf("%s (Bad option).\n", argv[i]);
+ return GL_FALSE;
+ }
+ }
+ return GL_TRUE;
+}
+
+void GLUTCALLBACK glut_post_redisplay_p(void)
+{
+ glutPostRedisplay();
+}
+
+int main(int argc, char **argv)
+{
+ GLenum type;
+
+ glutInit(&argc, argv);
+
+ if (Args(argc, argv) == GL_FALSE) {
+ exit(1);
+ }
+
+ if (fileName == 0) {
+ printf("No image file.\n");
+ exit(1);
+ }
+
+ image = LoadPPM(fileName);
+
+ /* changed powf and logf to pow and log -Brian */
+ imageSizeX = (int)pow(2.0, (float)((int)(log(image->sizeX)/log(2.0))));
+ imageSizeY = (int)pow(2.0, (float)((int)(log(image->sizeY)/log(2.0))));
+
+ glutInitWindowPosition(0, 0); glutInitWindowSize( imageSizeX, imageSizeY);
+
+ type = GLUT_RGB;
+ type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
+ glutInitDisplayMode(type);
+
+ if (glutCreateWindow("Stretch") == GL_FALSE) {
+ exit(1);
+ }
+
+ glViewport(0, 0, imageSizeX, imageSizeY);
+ gluOrtho2D(0, imageSizeX, 0, imageSizeY);
+ glClearColor(0.0, 0.0, 0.0, 0.0);
+
+ glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+ glPixelStorei(GL_PACK_ALIGNMENT, 1);
+
+ ScaleImage(imageSizeX, imageSizeY);
+
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexImage2D(GL_TEXTURE_2D, 0, 3, image->sizeX, image->sizeY, 0,
+ GL_RGB, GL_UNSIGNED_BYTE, (unsigned char *)image->data);
+
+ cCount = 0;
+ cIndex[0] = 0;
+ cIndex[1] = 0;
+ cStep = 0;
+ op = OP_DRAWIMAGE;
+
+ glutKeyboardFunc(Key);
+ glutMouseFunc(Mouse);
+ glutDisplayFunc(Animate);
+ glutIdleFunc(glut_post_redisplay_p);
+ glutMainLoop();
+ return 0;
+}