remake ps

main.c

@@ -44,7 +44,7 @@ static int parse_range(const char *str, struct graph_range *range) {
     return 1;
 }
 
-static enum error_code export_to_file(const struct expr_node *node, const struct graph_range *range, const char *out_name) {
+static enum error_code export_to_file(const struct expr_node *node, const struct graph_range *range, const char *function, const char *out_name) {
     FILE *file;
 
     if (!(file = fopen(out_name, "w"))) {
@@ -52,7 +52,7 @@ static enum error_code export_to_file(const struct expr_node *node, const struct
         return ERR_INVALID_FILENAME;
     }
     
-    ps_export_graph(file, node, range);
+    ps_generate_graph(file, node, range, function);
 
     fclose(file);
     return ERR_NO_ERR;
@@ -104,7 +104,7 @@ int main(int argc, char *argv[]) {
         return parser_get_error(&parser);
     }
     
-    err = export_to_file(node, &range, argv[2]);
+    err = export_to_file(node, &range, argv[1], argv[2]);
 
 #ifdef ENABLE_GRAPHVIZ_EXPORT
     export_gv(node, "graph.dot");

ps_graph.c

@@ -1,18 +1,77 @@
 #include "ps_graph.h"
 #include <math.h>
 
+#define TEMP_BUF_SIZE  128
+
+/* rozměry grafu */
 #define GRAPH_SIZE 400
 #define HALF_GRAPH_SIZE (GRAPH_SIZE / 2)
+
+#define GRAPH_CENTER_X 306
+#define GRAPH_CENTER_Y 500
+
+/* písmo */
+#define FONT "Helvetica"
+#define FONT_SIZE_HEADER    15
+#define FONT_SIZE_LABEL     12
+#define FONT_SIZE_VALUE     9
+
 #define GRID_STEP (GRAPH_SIZE / 10)
+
+/* posuny popisků */
+#define HEADER_OFFSET_Y (10)
+
+#define X_VAL_OFFSET_X (0)
+#define X_VAL_OFFSET_Y (-13)
+
+#define Y_VAL_OFFSET_X (-5)
+#define Y_VAL_OFFSET_Y (-3)
+
+#define X_LABEL_OFFSET_X (0)
+#define X_LABEL_OFFSET_Y (-30)
+
+#define Y_LABEL_OFFSET_X (-40)
+#define Y_LABEL_OFFSET_Y (-3)
+
+/* počet částí grafu funkce */
 #define FUNCTION_SEGMENTS 1000
 
-void ps_export_graph(FILE *file, const struct expr_node *node, const struct graph_range *range) {
+/* koeficienty pro zarovnání textu */
-    int i;
+#define ALIGN_CENTER    (-0.5)
-    double x;
+#define ALIGN_RIGHT     (-1.0)
-    int first = 1;
 
+static void generate_text_align(FILE *file, int x, int y, double alignment, const char *str) {
+    fprintf(file,
+        "newpath\n"
+        /* posun na cílovou pozici */
+        "%d %d moveto\n"
+        /* vložení dvou řetězců s popiskem */
+        "(%s) dup\n"
+        /* zjištění šířky a výšky řetežce, odstranění výšky ze zásobníku (nezajímá) */
+        "stringwidth pop\n"
+        /* koeficient pro zarovnání */
+        "%f mul\n"
+        /* posun o šířku doleva */
+        "0 rmoveto\n"
+        /* zobrazení řetězce */
+        "show\n"
+        "\n",
+        x, y, str, alignment
+    );
+}
+
+static void set_font(FILE *file, const char *font, int size) {
+    fprintf(file,
+        "/%s findfont\n"
+        "%d scalefont\n"
+        "setfont\n",
+        font, size
+    );
+}
+
+static void generate_grid(FILE *file, const struct graph_range *range) {
+    int i;
     fprintf(file,
-        "306 500 translate\n"
         "2 setlinewidth\n"
         "/gridline {\n"
         "   .5 setlinewidth\n"
@@ -26,62 +85,38 @@ void ps_export_graph(FILE *file, const struct expr_node *node, const struct grap
         "\n"
     );
 
-    /* mrizka */
     for (i = -HALF_GRAPH_SIZE + GRID_STEP; i < HALF_GRAPH_SIZE; i += GRID_STEP) {
         fprintf(file, "%5d     0 %5d %5d gridline\n", GRAPH_SIZE, -HALF_GRAPH_SIZE, i);
         fprintf(file, "    0 %5d %5d %5d gridline\n", GRAPH_SIZE, i, -HALF_GRAPH_SIZE);
     }
 
-    /* popisky */
+    set_font(file, FONT, FONT_SIZE_VALUE);
-    fprintf(file,
-        "/Arial findfont\n"
-        "10 scalefont\n"
-        "setfont\n"
-    );
 
+    /* hodnoty */
     for (i = -HALF_GRAPH_SIZE; i <= HALF_GRAPH_SIZE; i += GRID_STEP) {
         double inorm = (double)i / (double)GRAPH_SIZE + 0.5;
         double xval = range->xmax * inorm + range->xmin * (1.0 - inorm); 
         double yval = range->ymax * inorm + range->ymin * (1.0 - inorm); 
-        
+        char buf[TEMP_BUF_SIZE];
-        fprintf(file,
-            "newpath\n"
-            "%d %d moveto\n"
-            "(%.2f) dup\n"
-            "stringwidth pop neg\n"
-            "0 rmoveto\n"
-            "-10 -3 rmoveto\n"
-            "show\n"
-            "\n",
-            -HALF_GRAPH_SIZE, i, yval
-        );
 
-        fprintf(file,
+        /* hodnota osy y */
-            "newpath\n"
+        snprintf(buf, TEMP_BUF_SIZE, "%.2f", yval);
-            "%d %d moveto\n"
+        generate_text_align(file, -HALF_GRAPH_SIZE + Y_VAL_OFFSET_X, i + Y_VAL_OFFSET_Y, ALIGN_RIGHT, buf);
-            "(%.2f) dup\n"
+
-            "stringwidth pop\n"
+        /* hodnota osy x */
-            "2 div neg\n"
+        snprintf(buf, TEMP_BUF_SIZE, "%.2f", xval);
-            "-20 rmoveto\n"
+        generate_text_align(file, i + X_VAL_OFFSET_X, -HALF_GRAPH_SIZE + X_VAL_OFFSET_Y, ALIGN_CENTER, buf);
-            "show\n"
-            "\n",
-            i, -HALF_GRAPH_SIZE, xval
-        );
 
     }
 
-    fprintf(file,
+    set_font(file, FONT, FONT_SIZE_LABEL);
-        "[] 0 setdash\n"
+    generate_text_align(file, -HALF_GRAPH_SIZE + Y_LABEL_OFFSET_X, Y_LABEL_OFFSET_Y, ALIGN_RIGHT, "y");
-        "newpath\n"
+    generate_text_align(file, X_LABEL_OFFSET_X, -HALF_GRAPH_SIZE + X_LABEL_OFFSET_Y, ALIGN_CENTER, "x");
-        "%d %d moveto\n"
+}
-        "%d 0 rlineto\n"
+
-        "0 %d rlineto\n"
+static void generate_function(FILE *file, const struct expr_node *node, const struct graph_range *range) {
-        "%d 0 rlineto\n"
+    int i;
-        "closepath\n"
+    int first = 1;
-        "gsave\n"
-        "clip\n",
-        -HALF_GRAPH_SIZE, -HALF_GRAPH_SIZE, GRAPH_SIZE, GRAPH_SIZE, -GRAPH_SIZE 
-    );
 
     fprintf(file,
         "2 setlinewidth\n"
@@ -92,7 +127,7 @@ void ps_export_graph(FILE *file, const struct expr_node *node, const struct grap
     for (i = 0; i < FUNCTION_SEGMENTS; ++i) {
         const char *cmd = "lineto";
         double xpos, ypos;
-        double y;
+        double x, y;
        
         x = range->xmin + (range->xmax - range->xmin) * (double)i / (double)FUNCTION_SEGMENTS;
 
@@ -115,6 +150,35 @@ void ps_export_graph(FILE *file, const struct expr_node *node, const struct grap
     fprintf(file,
         "stroke\n"
     );
+}
+
+void ps_generate_graph(FILE *file, const struct expr_node *node, const struct graph_range *range, const char *function) {
+    char buf[TEMP_BUF_SIZE];
+    
+    fprintf(file, "%d %d translate\n", GRAPH_CENTER_X, GRAPH_CENTER_Y);
+
+    if (function) {
+        set_font(file, FONT, FONT_SIZE_HEADER);
+        snprintf(buf, TEMP_BUF_SIZE, "y = %s", function);
+        generate_text_align(file, 0, HALF_GRAPH_SIZE + HEADER_OFFSET_Y, ALIGN_CENTER, buf);
+    }
+
+    generate_grid(file, range);
+
+    fprintf(file,
+        "[] 0 setdash\n"
+        "newpath\n"
+        "%d %d moveto\n"
+        "%d 0 rlineto\n"
+        "0 %d rlineto\n"
+        "%d 0 rlineto\n"
+        "closepath\n"
+        "gsave\n"
+        "clip\n",
+        -HALF_GRAPH_SIZE, -HALF_GRAPH_SIZE, GRAPH_SIZE, GRAPH_SIZE, -GRAPH_SIZE 
+    );
+
+    generate_function(file, node, range);
 
     fprintf(file,
         "grestore\n"
@@ -122,6 +186,4 @@ void ps_export_graph(FILE *file, const struct expr_node *node, const struct grap
         "0 0 0 setrgbcolor\n"
         "stroke\n"
     );
-
-
 }

ps_graph.h

@@ -9,6 +9,6 @@ struct graph_range {
 	double ymin, ymax;
 };
 
-extern void ps_export_graph(FILE *file, const struct expr_node *node, const struct graph_range *range);
+extern void ps_generate_graph(FILE *file, const struct expr_node *node, const struct graph_range *range, const char *function);
 
 #endif