X-Git-Url: http://pileus.org/git/?p=grits;a=blobdiff_plain;f=src%2Fopengl.c;h=e9d4a7e3a0a6d44ea35d6f361e4b8ec1f4db4f8d;hp=9a369eca3afb096bb7c0a08bc8a0faedfacf44a6;hb=f230908a4780fd954772bbc3d17658aba86baea8;hpb=4308f69c781166b035bc0d0782fd974a9e1372b6

diff --git a/src/opengl.c b/src/opengl.c
index 9a369ec..e9d4a7e 100644
--- a/src/opengl.c
+++ b/src/opengl.c
@@ -1,10 +1,13 @@
 #include <config.h>
+#include <math.h>
 #include <gtk/gtk.h>
 #include <gtk/gtkgl.h>
 #include <GL/gl.h>
+#include <GL/glu.h>
 
 static gboolean expose_start(GtkWidget *da, GdkEventExpose *event, gpointer user_data)
 {
+	g_message("opengl:expose_start");
 	GdkGLContext *glcontext = gtk_widget_get_gl_context(da);
 	GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(da);
 
@@ -19,7 +22,9 @@ static gboolean expose_start(GtkWidget *da, GdkEventExpose *event, gpointer user
 /* Plugins run stuff here */
 static gboolean expose_end(GtkWidget *da, GdkEventExpose *event, gpointer user_data)
 {
-	GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(da);
+	g_message("opengl:expose_end\n");
+
+	GdkGLDrawable *gldrawable = gdk_gl_drawable_get_current();
 
 	if (gdk_gl_drawable_is_double_buffered(gldrawable))
 		gdk_gl_drawable_swap_buffers(gldrawable);
@@ -38,20 +43,47 @@ static gboolean configure_start(GtkWidget *da, GdkEventConfigure *event, gpointe
 	if (!gdk_gl_drawable_gl_begin(gldrawable, glcontext))
 		g_assert_not_reached();
 
-	glLoadIdentity();
-	glViewport(0, 0, da->allocation.width, da->allocation.height);
+
+	double width  = da->allocation.width;
+	double height = da->allocation.height;
+	double dist   = 500*1000; // 500 km
+
+	/* Misc */
+	glViewport(0, 0, width, height);
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-	//glEnable(GL_ALPHA_TEST);
-	//glAlphaFunc(GL_EQUAL, 0);
-	double scale = 500*1000; // 500 km
-	glOrtho(-scale,scale,-scale,scale,0,10000);
+	glClearColor(0.8f, 0.8f, 1.0f, 0.0f);
+
+	/* Tessellation, "finding intersecting triangles" */
+	/* http://research.microsoft.com/pubs/70307/tr-2006-81.pdf */
+	/* http://www.opengl.org/wiki/Alpha_Blending */
+	glAlphaFunc(GL_GREATER,0.1);
+	glEnable(GL_ALPHA_TEST);
+
+	/* Depth test */
+	glClearDepth(1.0);
+	glDepthFunc(GL_LEQUAL);
+	glEnable(GL_DEPTH_TEST);
+
+	/* Perspective */
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	double rad = atan(height/2*1000.0/dist); // 1px = 1000 meters
+	double deg = (rad*180)/M_PI;
+	gluPerspective(deg*2, width/height, dist-20, dist+20);
+
+	/* Camera position? */
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glTranslatef(0.0, 0.0, -dist);
+	//glRotatef(-45, 1, 0, 0);
+
 
 	return FALSE;
 }
 static gboolean configure_end(GtkWidget *da, GdkEventConfigure *event, gpointer user_data)
 {
-	GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(da);
+	GdkGLDrawable *gldrawable = gdk_gl_drawable_get_current();
 	gdk_gl_drawable_gl_end(gldrawable);
 	return FALSE;
 }