Added gr_mathtex function (LaTeX equation support)

Author: jheinen

lib/gr/Makefile

@@ -4,7 +4,7 @@
       INCDIR = $(GRDIR)/include
 
       GROBJS = gr.o text.o contour.o spline.o strlib.o property.o image.o \
-               grforbnd.o
+               md5.o grforbnd.o
      DEFINES =
     INCLUDES = -I../gks -I../jpeg -I../png
           CC = cc
@@ -70,7 +70,7 @@ clean:
 
 depend:
 	makedepend -Y -- gr.c text.c contour.c spline.c strlib.c property.c \
-	image.c grforbnd.c 2> /dev/null
+	image.c md5.c grforbnd.c 2> /dev/null
 
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
@@ -80,4 +80,5 @@ spline.o: spline.h
 strlib.o: strlib.h
 property.o: property.h
 image.o: gr.h
+md5.o: md5.h
 grforbnd.o: gr.h

lib/gr/gr.c

@@ -20,6 +20,7 @@
 #include "contour.h"
 #include "strlib.h"
 #include "property.h"
+#include "md5.h"
 
 typedef struct
 {
@@ -134,6 +135,9 @@ FILE *stream;
 #define GR_HEADER  "<?xml version='1.0' encoding='ISO-8859-1'?>\n<gr>\n"
 #define GR_TRAILER "</gr>\n"
 
+#define nominalWindowHeight 500
+#define qualityFactor 4
+
 typedef enum
 {
   OPTION_LINES, OPTION_MESH, OPTION_FILLED_MESH, OPTION_Z_SHADED_MESH,
@@ -4948,6 +4952,107 @@ void gr_endgraphics(void)
     }
 }
 
+static
+void latex2image(char *string, int pointSize, float *rgb,
+                 int *width, int *height, int **data)
+{
+  int color;
+  char s[FILENAME_MAX], path[FILENAME_MAX], cache[33];
+  char *tmp, *null, cmd[1024];
+  char tex[FILENAME_MAX], dvi[FILENAME_MAX], png[FILENAME_MAX];
+  FILE *stream;
+
+  color = ((int)(rgb[0] / 255)      ) + 
+          ((int)(rgb[1] / 255) <<  8) +
+          ((int)(rgb[2] / 255) << 16); 
+  sprintf(s, "%d%x%s", pointSize, color, string);
+  md5(s, cache);
+#ifdef WIN32
+  sprintf(path, "C:\\TEMP\\gr-cache-%s.png", cache);
+#else
+  sprintf(path, "/tmp/gr-cache-%s.png", cache);
+#endif
+
+  if (access(path, R_OK) != 0)
+    {
+      tmp = tempnam(".", NULL);
+      sprintf(tex, "%s.tex", tmp);
+      sprintf(dvi, "%s.dvi", tmp);
+      sprintf(png, "%s.png", tmp);
+#ifdef _WN32
+      null = "NUL";
+#else
+      null = "/dev/null";
+#endif
+
+      stream = fopen(tex, "w");
+      fprintf(stream, "\
+\\documentclass{article}\n\
+\\pagestyle{empty}\n\
+\\usepackage[dvips]{color}\n\
+\\color[rgb]{%.3f,%.3f,%.3f}\n\
+\\begin{document}\n\
+\\[\n", rgb[0], rgb[1], rgb[2]);
+      fwrite(string, strlen(string), 1, stream);
+      fprintf(stream, "\n\
+\\]\n\
+\\end{document}");
+      fclose(stream);
+
+      sprintf(cmd, "latex -interaction=batchmode -halt-on-error %s -o %s >%s",
+              tex, dvi, null);
+      system(cmd);
+
+      if (access(dvi, R_OK) == 0)
+        {
+          sprintf(cmd, "dvipng -q -T tight -x %d %s -o %s >%s",
+                  pointSize * 100, dvi, png, null);
+          system(cmd);
+
+          rename(png, path);
+
+          sprintf(cmd, "rm -f %s.*", tmp);
+          system(cmd);
+        }
+    }
+
+  if (access(path, R_OK) == 0)
+    gr_readimage(path, width, height, data);
+}
+
+void gr_mathtex(float x, float y, char *string)
+{
+  int errind, pointSize, color;
+  float chh, rgb[3];
+  int width, height, *data = NULL;
+  float w, h, xmin, xmax, ymin, ymax;
+
+  check_autoinit;
+
+  gks_inq_text_height(&errind, &chh);
+  pointSize = chh * qualityFactor * nominalWindowHeight;
+
+  gks_inq_text_color_index(&errind, &color);
+  gks_inq_rgb(color, &rgb[0], &rgb[1], &rgb[2]);
+
+  latex2image(string, pointSize, rgb, &width, &height, &data);
+
+  if (data != NULL)
+    {
+      w =  width / (float) (qualityFactor * nominalWindowHeight);
+      h = height / (float) (qualityFactor * nominalWindowHeight);
+      xmin = x - 0.5 * w;
+      xmax = x + 0.5 * w;
+      ymin = y - 0.5 * h;
+      ymax = y + 0.5 * h;
+
+      gr_selntran(0);
+      gr_drawimage(xmin, xmax, ymin, ymax, width, height, data);
+
+      free(data);
+    }
+}
+
 void gr_beginselection(int index, int type)
 {
   check_autoinit;

lib/gr/gr.h

@@ -116,6 +116,7 @@ DLLEXPORT void gr_settransparency(float);
 DLLEXPORT void gr_setcoordxform(float [3][2]);
 DLLEXPORT void gr_begingraphics(char *);
 DLLEXPORT void gr_endgraphics(void);
+DLLEXPORT void gr_mathtex(float, float, char *);
 DLLEXPORT void gr_beginselection(int, int);
 DLLEXPORT void gr_endselection(void);
 DLLEXPORT void gr_moveselection(float, float);

lib/gr/grforbnd.c

@@ -540,3 +540,17 @@ void FORTRAN(gr_endgraphics)(void)
 {
   gr_endgraphics();
 }
+
+void FORTRAN(gr_mathtex)(
+  float *x, float *y, char *string, unsigned char string_len)
+{
+  char *_string;
+
+  _string = (char *) calloc(1, sizeof(char) * string_len);
+  strncpy(_string, string, string_len);
+
+  gr_mathtex(*x, *y, _string);
+
+  free(_string);
+}
+

lib/gr/libgr.def

@@ -37,6 +37,7 @@ EXPORTS
 	gr_inqtextext
 	gr_moveselection
 	gr_ndctowc
+	gr_mathtex
 	gr_opengks
 	gr_openws
 	gr_polyline

lib/gr/makefile.vc

@@ -46,7 +46,7 @@ $(ZLIBS):
 libgr.lib: libgr.dll
 
 libgr.dll: gr.obj text.obj contour.obj spline.obj strlib.obj property.obj \
-	   image.obj
+	   image.obj md5.obj
 	$(DLLLINK) /out:$@ $** -def:libgr.def \
 	$(JPEGLIBS) $(PNGLIBS) $(ZLIBS) $(GKSLIBS) $(DLLLFLAGS) $(DLLLIBS)