Fun with shaders

git-svn-id: svn://cook.msm.cam.ac.uk:745/diff-tomo/dtr@235 bf6ca9ba-c028-0410-8290-897cf20841d1

7 files changed, 166 insertions, 24 deletions

diff --git a/data/Makefile.am b/data/Makefile.am
index 717d3e5..2948e73 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -1,5 +1,5 @@
 dtrdir = $(datadir)/dtr
-dtr_DATA = displaywindow.ui
+dtr_DATA = displaywindow.ui light-pp.vert light-pp.frag
 
 iconsdir = $(datadir)/icons/hicolor/scalable/apps
 icons_DATA = dtr-tiltaxis.svg dtr-dirax.svg dtr-refine.svg dtr-refineall.svg dtr-quantify.svg
diff --git a/data/light-pp.frag b/data/light-pp.frag
new file mode 100644
index 0000000..c862641
--- /dev/null
+++ b/data/light-pp.frag
@@ -0,0 +1,40 @@
+/*
+ * light-pp.frag
+ *
+ * Lighting per pixel
+ *
+ * (c) 2007 Thomas White <taw27@cam.ac.uk>
+ *
+ *  dtr - Diffraction Tomography Reconstruction
+ *
+ */
+
+varying vec4 col_ambi;
+varying vec4 col_diff;
+varying vec4 col_spec;
+varying float shininess;
+
+varying vec3 normal;
+varying vec3 halfvc;
+
+void main() {
+	
+	vec4 ambi;
+	vec4 diff;
+	vec4 spec;
+	
+	/* Ambient contribution */
+	ambi = col_ambi * gl_LightModel.ambient;
+	ambi += col_ambi * gl_LightSource[0].ambient;
+	
+	/* Diffuse contribution */
+	diff = col_diff * clamp(dot( vec3(normalize(gl_LightSource[0].position)), normal ), 0.0, 1.0);
+	
+	/* Specular contribution */
+	spec = col_spec * pow(dot( vec3(normal), halfvc ), shininess);
+	
+	gl_FragColor = ambi + diff + spec;
+	gl_FragColor.a = 1.0;
+	
+}
+
diff --git a/data/light-pp.vert b/data/light-pp.vert
new file mode 100644
index 0000000..02ff444
--- /dev/null
+++ b/data/light-pp.vert
@@ -0,0 +1,34 @@
+/*
+ * light-pp.vert
+ *
+ * Lighting per pixel
+ *
+ * (c) 2007 Thomas White <taw27@cam.ac.uk>
+ *
+ *  dtr - Diffraction Tomography Reconstruction
+ *
+ */
+
+varying vec4 col_ambi;
+varying vec4 col_diff;
+varying vec4 col_spec;
+varying float shininess;
+
+varying vec3 normal;
+varying vec3 halfvc;
+
+void main() {
+	
+	normal = normalize(gl_NormalMatrix * gl_Normal);
+	halfvc = vec3(gl_LightSource[0].halfVector);
+	
+	col_ambi = gl_FrontMaterial.ambient;
+	col_diff = gl_FrontMaterial.diffuse;
+	col_spec = gl_FrontMaterial.specular;
+	
+	shininess = gl_FrontMaterial.shininess;
+	
+	gl_Position = ftransform();
+	
+}
+
diff --git a/src/displaywindow.c b/src/displaywindow.c
index 46b4822..4f30a3d 100644
--- a/src/displaywindow.c
+++ b/src/displaywindow.c
@@ -111,28 +111,7 @@ static gint displaywindow_gl_motion_notify(GtkWidget *widget, GdkEventMotion *ev
 	
 }
 
-static gint displaywindow_gl_realise(GtkWidget *widget, DisplayWindow *dw) {
-
-	GdkGLContext *glcontext = gtk_widget_get_gl_context(widget);
-	GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(widget);
-	GLfloat w = widget->allocation.width;
-	GLfloat h = widget->allocation.height;
-	
-	if ( !gdk_gl_drawable_gl_begin(gldrawable, glcontext) ) {
-		return 0;
-	}
-	
-	glbits_set_ortho(dw, w, h);
-	glbits_prepare(dw);
-	
-	gdk_gl_drawable_gl_end(gldrawable);
-
-	return 0;
-
-}
-
 static gint displaywindow_closedown(GtkWidget *widget, DisplayWindow *dw) {
-	glbits_free_resources(dw);
 	gtk_exit(0);
 	return 0;
 }
@@ -367,6 +346,11 @@ static gint displaywindow_refinestack(GtkWidget *widget, DisplayWindow *dw) {
 	return 0;
 }
 
+static gint displaywindow_gl_destroyed(GtkWidget *widget, DisplayWindow *dw) {
+	glbits_final_free_resources(dw);
+	return 0;
+}
+
 static gint displaywindow_extract(GtkWidget *widget, DisplayWindow *dw) {
 	
 	GtkWidget *d;
@@ -612,10 +596,11 @@ DisplayWindow *displaywindow_open(ControlContext *ctx) {
 	gtk_notebook_append_page(GTK_NOTEBOOK(notebook), dw->drawing_area, gtk_label_new("Reconstruction"));
 	gtk_widget_add_events(dw->drawing_area, GDK_BUTTON1_MOTION_MASK | GDK_BUTTON_PRESS_MASK | GDK_VISIBILITY_NOTIFY_MASK);
 	g_signal_connect(GTK_OBJECT(dw->drawing_area), "configure_event", G_CALLBACK(glbits_configure), dw);
-	g_signal_connect(GTK_OBJECT(dw->drawing_area), "realize", G_CALLBACK(displaywindow_gl_realise), dw);
+	g_signal_connect(GTK_OBJECT(dw->drawing_area), "realize", G_CALLBACK(glbits_realise), dw);
 	g_signal_connect(GTK_OBJECT(dw->drawing_area), "expose_event", G_CALLBACK(glbits_expose), dw);
 	g_signal_connect(GTK_OBJECT(dw->drawing_area), "button_press_event", G_CALLBACK(displaywindow_gl_button_press), dw);
 	g_signal_connect(GTK_OBJECT(dw->drawing_area), "motion_notify_event", G_CALLBACK(displaywindow_gl_motion_notify), dw);
+	g_signal_connect(GTK_OBJECT(dw->drawing_area), "destroy", G_CALLBACK(displaywindow_gl_destroyed), dw);
 	
 	dw->stack = imagedisplay_new_nowindow(ctx->images->images[dw->cur_image], IMAGEDISPLAY_SHOW_TILT_AXIS | IMAGEDISPLAY_SHOW_CENTRE, NULL, NULL, NULL);
 	gtk_notebook_append_page(GTK_NOTEBOOK(notebook), dw->stack->vbox, gtk_label_new("Image Stack"));
diff --git a/src/displaywindow.h b/src/displaywindow.h
index 86d2645..baab13d 100644
--- a/src/displaywindow.h
+++ b/src/displaywindow.h
@@ -64,6 +64,9 @@ typedef struct dw_struct {
 	GLuint			gl_line_vertex_buffer;		/* Indexing line stuff */
 	GLfloat			*gl_line_vertex_array;
 	GLsizei			gl_line_num_vertices;
+	GLhandleARB		gl_vshader_lightpp;
+	GLhandleARB		gl_fshader_lightpp;
+	GLhandleARB		gl_program_lightpp;
 	
 	/* Display parameters */
 	DisplayWindowView	view;
diff --git a/src/glbits.c b/src/glbits.c
index 194a919..9a7fca5 100644
--- a/src/glbits.c
+++ b/src/glbits.c
@@ -28,7 +28,53 @@
 #include "reflections.h"
 #include "image.h"
 
-#define BLOB_BITS 5
+/* Utility function to load and compile a shader, checking the info log */
+static GLhandleARB glbits_load_shader(const char *filename, GLenum type) {
+
+	GLhandleARB shader;
+	char text[4096];
+	size_t len;
+	FILE *fh;
+	int l;
+	
+	fh = fopen(filename, "r");
+	len = fread(text, 1, 4095, fh);
+	fclose(fh);
+	text[len] = '\0';
+	const GLcharARB *source = text;
+	shader = glCreateShaderObjectARB(type);
+	glShaderSourceARB(shader, 1, &source, NULL);
+	glCompileShaderARB(shader);
+	glGetInfoLogARB(shader, 4095, &l, text);
+	if ( l > 0 ) {
+		printf("%s\n", text); fflush(stdout);
+	}
+	
+	return shader;
+	
+}
+
+static void glbits_load_shaders(DisplayWindow *dw) {
+	
+	dw->gl_vshader_lightpp = glbits_load_shader(DATADIR"/dtr/light-pp.vert", GL_VERTEX_SHADER_ARB);
+	dw->gl_fshader_lightpp = glbits_load_shader(DATADIR"/dtr/light-pp.frag", GL_FRAGMENT_SHADER_ARB);
+		
+	dw->gl_program_lightpp = glCreateProgramObjectARB();
+	glAttachObjectARB(dw->gl_program_lightpp, dw->gl_vshader_lightpp);
+	glAttachObjectARB(dw->gl_program_lightpp, dw->gl_fshader_lightpp);
+	glLinkProgramARB(dw->gl_program_lightpp);
+	
+}
+
+static void glbits_delete_shaders(DisplayWindow *dw) {
+
+	glDetachObjectARB(dw->gl_program_lightpp, dw->gl_fshader_lightpp);
+	glDeleteObjectARB(dw->gl_fshader_lightpp);
+	glDeleteObjectARB(dw->gl_program_lightpp);
+
+}
+
+#define BLOB_BITS 7
 #define VERTICES_IN_A_BLOB 4*BLOB_BITS*BLOB_BITS*2
 #define ADD_VERTEX 						\
 	vertices[3*i + 0] = reflection->x/1e9 + size*xv;	\
@@ -704,6 +750,7 @@ gint glbits_expose(GtkWidget *widget, GdkEventExpose *event, DisplayWindow *dw)
 			glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, gold);
 			glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, gold_spec);
 			glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 70.0);
+			glUseProgramObjectARB(dw->gl_program_lightpp);
 			if ( dw->gl_use_buffers ) {
 				glBindBufferARB(GL_ARRAY_BUFFER, dw->gl_gen_vertex_buffer);
 				glVertexPointer(3, GL_FLOAT, 0, NULL);
@@ -716,6 +763,7 @@ gint glbits_expose(GtkWidget *widget, GdkEventExpose *event, DisplayWindow *dw)
 				glNormalPointer(GL_FLOAT, 0, dw->gl_gen_normal_array);
 				glDrawArrays(GL_QUADS, 0, dw->gl_gen_num_vertices);
 			}
+			glUseProgramObjectARB(0);
 			glDisableClientState(GL_NORMAL_ARRAY);
 			glPopClientAttrib();
 		}
@@ -812,3 +860,33 @@ void glbits_free_resources(DisplayWindow *dw) {
 	
 }
 
+void glbits_final_free_resources(DisplayWindow *dw) {
+	glbits_free_resources(dw);
+	glbits_delete_shaders(dw);
+}
+
+static void glbits_first_prepare(DisplayWindow *dw) {
+	glbits_prepare(dw);
+	glbits_load_shaders(dw);
+}
+
+gint glbits_realise(GtkWidget *widget, DisplayWindow *dw) {
+
+	GdkGLContext *glcontext = gtk_widget_get_gl_context(widget);
+	GdkGLDrawable *gldrawable = gtk_widget_get_gl_drawable(widget);
+	GLfloat w = widget->allocation.width;
+	GLfloat h = widget->allocation.height;
+	
+	if ( !gdk_gl_drawable_gl_begin(gldrawable, glcontext) ) {
+		return 0;
+	}
+	
+	glbits_set_ortho(dw, w, h);
+	glbits_first_prepare(dw);
+	
+	gdk_gl_drawable_gl_end(gldrawable);
+
+	return 0;
+
+}
+
diff --git a/src/glbits.h b/src/glbits.h
index 58520fd..a958217 100644
--- a/src/glbits.h
+++ b/src/glbits.h
@@ -26,6 +26,8 @@ extern void glbits_set_ortho(DisplayWindow *dw, GLfloat w, GLfloat h);
 extern void glbits_set_perspective(DisplayWindow *dw, GLfloat w, GLfloat h);
 extern gboolean glbits_configure(GtkWidget *widget, GdkEventConfigure *event, DisplayWindow *dw);
 extern void glbits_free_resources(DisplayWindow *dw);
+extern void glbits_final_free_resources(DisplayWindow *dw);
+extern gint glbits_realise(GtkWidget *widget, DisplayWindow *dw);
 
 #endif	/* GLBITS_H */