stl: added the beginning of a viewer

git-svn-id: svn://anubis/misc/stl@5 bd8a9e45-a331-0410-811e-c64571078777

Makefile

@@ -0,0 +1,14 @@
+
+CFLAGS = -O2 `sdl-config --cflags`
+LDFLAGS = `sdl-config --libs` -lGL -lGLU
+
+all: stl-viewer
+
+stl-viewer: stl-viewer.o stl.o
+	gcc -o $@ $^ $(LDFLAGS)
+
+stl-viewer.o: stl-viewer.c stl.h
+	gcc -c -o $@ $< $(CFLAGS)
+
+stl.o: stl.c stl.h
+	gcc -c -o $@ $< $(CFLAGS)

stl-viewer.c

@@ -0,0 +1,133 @@
+
+#include <SDL/SDL.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+#include "stl.h"
+
+#define WIDTH	500
+#define HEIGHT	500
+
+stl_t * stl = NULL;
+GLuint stldl;
+GLfloat default_color[] = {1, 1, 1, 1};
+
+GLuint	buildDL(void);
+void	init(void);
+void	display(void);
+void	reshape(GLsizei w, GLsizei h);
+
+void	init(void)
+{
+	glClearColor (0.0, 0.0, 0.0, 0.0);
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_LIGHTING);
+	glEnable(GL_LIGHT0);
+	glShadeModel(GL_SMOOTH);
+}
+
+void	display(void)
+{
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glBegin(GL_QUADS);
+	    glVertex3f(-2.0, -1.0, 0.0);
+	    glVertex3f(-2.0, 1.0, 0.0);
+	    glVertex3f(0.0, 1.0, 0.0);
+	    glVertex3f(0.0, -1.0, 0.0);
+	glEnd();
+	SDL_GL_SwapBuffers();
+}
+
+void reshape(GLsizei w, GLsizei h)
+{
+	glViewport(0, 0, w, h);
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	gluPerspective(60.0, 1.0*(GLfloat)w/(GLfloat)h, 1.0, 30.0);
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glTranslatef(0.0, 0.0, -3.6);
+}
+
+int	main(int argc, char *argv[])
+{
+	if (argc != 2)
+	{
+		fprintf(stderr, "Usage: %s <stl-file>\n", argv[0]);
+		return -1;
+	}
+	
+	stl = stl_load(argv[1]);
+	if (stl == NULL)
+	{
+		fprintf(stderr, "Error loading '%s'\n", argv[1]);
+		return -2;
+	}
+	stldl = buildDL();
+	
+	if (SDL_Init(SDL_INIT_VIDEO))
+	{
+		fprintf(stderr, "Failed to initialize SDL!\n");
+		return 1;
+	}
+
+	atexit(SDL_Quit);
+
+	SDL_Surface *screen;
+	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+	if (!(screen = SDL_SetVideoMode(WIDTH, HEIGHT, 16, SDL_OPENGL)))
+	{
+		fprintf(stderr, "Failed to set video mode!\n");
+		return 2;
+	}
+	SDL_WM_SetCaption(argv[0], argv[0]);
+
+	init();
+	reshape(WIDTH, HEIGHT);
+	display();
+	SDL_Event event;
+	while (SDL_WaitEvent(&event))
+	{
+		if (event.type == SDL_QUIT)
+			break;
+		else if (event.type == SDL_KEYDOWN)
+		{
+			if (event.key.keysym.sym == SDLK_ESCAPE)
+				break;
+		}
+	}
+
+	free(stl);
+}
+
+GLuint	buildDL(void)
+{
+	unsigned int n_faces = stl_num_faces(stl);
+	unsigned int i;
+	int dfltClrAct = 1;
+	GLfloat color[4];
+	color[3] = 0.0f;
+	GLuint dl = glGenLists(1);
+	glNewList(dl, GL_COMPILE);
+	glBegin(GL_TRIANGLES);
+	glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, default_color);
+	for (i = 0; i < n_faces; i++)
+	{
+		if (stl_attr_color_valid(stl_face(stl, i).attribute))
+		{
+			color[0] = stl_attr_color_r(stl_face(stl, i).attribute) / (float) 255;
+			color[1] = stl_attr_color_g(stl_face(stl, i).attribute) / (float) 255;
+			color[2] = stl_attr_color_b(stl_face(stl, i).attribute) / (float) 255;
+			glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, color);
+			dfltClrAct = 0;
+		}
+		else if (!dfltClrAct)
+			glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE,
+				default_color);
+		int j;
+		for (j = 0; j < 3; j++)
+			glVertex3fv(stl_face(stl, i).vertices[j]);
+	}
+	glEnd();
+	glEndList();
+	return dl;
+}

stl.c

@@ -1,6 +1,7 @@
 
-#include <sys/stat.h>
-#include <stdio.h>
+#include <sys/stat.h>		/* struct stat */
+#include <stdlib.h>		/* malloc() */
+#include <stdio.h>		/* fprintf() */
 #include "stl.h"
 
 /* load a STL file and return a pointer to the stl_t struct */
@@ -8,19 +9,29 @@ stl_t *	stl_load(const char * filename)
 {
 	struct stat s;
 	if (stat(filename, &s))
+	{
+		fprintf(stderr, "Couldn't stat '%s'\n", filename);
 		return NULL;
-	int size = s.st_size;
-	if (size < sizeof(stl_t))
+	}
+	if (s.st_size < sizeof(stl_t))
+	{
+		fprintf(stderr, "Size of '%s' only %d bytes!\n", filename, s.st_size);
 		return NULL;
+	}
 	FILE *fil;
 	if ((fil = fopen(filename, "rb")) == NULL)
+	{
+		fprintf(stderr, "Couldn't open '%s'\n", filename);
 		return NULL;
+	}
 	stl_t * stl = (stl_t *) malloc(s.st_size);
 	fread(stl, 1, s.st_size, fil);
 	fclose(fil);
 	if (s.st_size <
 		sizeof(stl_t) + sizeof(stl_face_t) * (stl_num_faces(stl)-1))
 	{
+		fprintf(stderr, "Size of '%s' only %d bytes, but has %d faces!\n",
+			filename, s.st_size, stl_num_faces(stl));
 		free(stl);
 		return NULL;
 	}

stl.h

@@ -25,14 +25,14 @@ typedef struct stl_face_s
 	float		normal[3];
 	float		vertices[3][3];
 	unsigned short	attribute;
-} stl_face_t;
+} __attribute__ ((packed)) stl_face_t;
 
 typedef struct stl_s
 {
 	char		header[STL_HEADER_LENGTH];
 	unsigned int	n_faces;
 	stl_face_t	faces[1];
-} stl_t;
+} __attribute__ ((packed)) stl_t;
 
 
 /* functions */