gl/examples: add a live shader demo using the new GstGLSLStage

Implemented with videotestsrc ! glshader ! glupload ! gtkglsink

Errors on an invalid shader compilation are ignored however any error
provided by the glsl compiler is printed to stdout.
This commit is contained in:
Matthew Waters 2015-10-17 01:08:29 +11:00
parent 136f375f01
commit b8b9c78599
2 changed files with 367 additions and 1 deletions

View file

@ -9,7 +9,7 @@ gtksink_LDADD = $(GTK3_LIBS) \
if USE_GTK3_GL if USE_GTK3_GL
if USE_GL if USE_GL
noinst_PROGRAMS += gtkglsink noinst_PROGRAMS += gtkglsink glliveshader
gtkglsink_SOURCES = gtkglsink.c gtkglsink_SOURCES = gtkglsink.c
gtkglsink_CFLAGS = $(GTK3_CFLAGS) \ gtkglsink_CFLAGS = $(GTK3_CFLAGS) \
@ -20,5 +20,18 @@ gtkglsink_CFLAGS = $(GTK3_CFLAGS) \
gtkglsink_LDADD = $(GTK3_LIBS) \ gtkglsink_LDADD = $(GTK3_LIBS) \
$(GST_LIBS) \ $(GST_LIBS) \
$(GL_LIBS) $(GL_LIBS)
glliveshader_SOURCES = glliveshader.c
glliveshader_CFLAGS = $(GTK3_CFLAGS) \
-I$(top_srcdir)/gst-libs \
-I$(top_builddir)/gst-libs \
$(GST_PLUGINS_BAD_CFLAGS) \
$(GST_PLUGINS_BASE_CFLAGS) \
$(GST_CFLAGS) \
$(GL_CFLAGS)
glliveshader_LDADD = $(GTK3_LIBS) \
$(GST_LIBS) \
$(GL_LIBS) \
$(top_builddir)/gst-libs/gst/gl/libgstgl-$(GST_API_VERSION).la
endif endif
endif endif

View file

@ -0,0 +1,353 @@
/*
* GStreamer
* Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include <gst/gst.h>
#include <gst/gl/gl.h>
#include <gtk/gtk.h>
#if GST_GL_HAVE_WINDOW_X11
#include <X11/Xlib.h>
#endif
static GMainLoop *loop;
static const gchar *vert = "#version 330\n\
in vec4 a_position;\n\
in vec2 a_texcoord;\n\
out vec2 v_texcoord;\n\
uniform float time;\n\
uniform float width;\n\
uniform float height;\n\
void main()\n\
{\n\
gl_Position = a_position;\n\
v_texcoord = a_texcoord;\n\
}\n";
static const gchar *geom = "#version 330\n\
\n\
layout(triangles) in;\n\
layout(triangle_strip, max_vertices = 3) out;\n\
in vec2 v_texcoord[];\n\
out vec2 g_texcoord;\n\
\n\
void main() {\n\
for(int i = 0; i < 3; i++) {\n\
gl_Position = gl_in[i].gl_Position;\n\
g_texcoord = v_texcoord[i];\n\
EmitVertex();\n\
}\n\
EndPrimitive();\n\
}\n";
static const gchar *frag = "#version 330\n\
in vec2 g_texcoord;\n\
uniform sampler2D tex;\n\
uniform float time;\n\
uniform float width;\n\
uniform float height;\n\
void main()\n\
{\n\
gl_FragColor = texture2D(tex, g_texcoord);\n\
}\n";
#define MAX_SHADER_STAGES 8
struct shader_state;
struct text_view_state
{
struct shader_state *state;
GLenum type;
gchar *str;
};
struct shader_state
{
GstGLContext *context;
GstElement *shader;
gboolean shader_linked;
GtkWidget *label;
struct text_view_state text_states[MAX_SHADER_STAGES];
gint n_stages;
};
static gboolean
bus_call (GstBus * bus, GstMessage * msg, gpointer data)
{
switch (GST_MESSAGE_TYPE (msg)) {
case GST_MESSAGE_EOS:
g_print ("End of stream\n");
g_main_loop_quit (loop);
break;
case GST_MESSAGE_ERROR:{
gchar *debug;
GError *error;
gst_message_parse_error (msg, &error, &debug);
g_free (debug);
g_printerr ("Error: %s\n", error->message);
g_error_free (error);
g_main_loop_quit (loop);
break;
}
default:
break;
}
return TRUE;
}
static gchar *
_find_source_for_shader_type (struct shader_state *state, GLenum type)
{
int i = 0;
for (i = 0; i < state->n_stages; i++) {
if (state->text_states[i].type == type)
return state->text_states[i].str;
}
return NULL;
}
static gboolean
_add_stage_to_shader (GstGLShader * shader, struct shader_state *state,
GLenum type, const gchar * default_src)
{
GError *error = NULL;
GstGLSLVersion version;
GstGLSLProfile profile;
GstGLSLStage *stage;
const gchar *src;
src = _find_source_for_shader_type (state, type);
if (!src)
src = default_src;
if (!src)
/* FIXME: assume this stage is not needed */
return TRUE;
if (!gst_glsl_string_get_version_profile (src, &version, &profile)) {
g_print ("Warning: failed to retreive GLSL version and profile for "
"shader type 0x%x\nsrc:\n%s\n", type, src);
}
if (!(stage = gst_glsl_stage_new_with_string (shader->context, type,
version, profile, src))) {
g_print ("Error: Failed to create GLSL Stage from src:\n%s\n", src);
return FALSE;
}
if (!gst_gl_shader_compile_attach_stage (shader, stage, &error)) {
/* ignore failed shader compilations */
g_print ("%s", error->message);
return FALSE;
}
return TRUE;
}
static GstGLShader *
_new_shader (GstGLContext * context, struct shader_state *state)
{
GstGLShader *shader = gst_gl_shader_new (context);
GError *error = NULL;
if (!_add_stage_to_shader (shader, state, GL_VERTEX_SHADER, vert)) {
gst_object_unref (shader);
return NULL;
}
if (!_add_stage_to_shader (shader, state, GL_GEOMETRY_SHADER, geom)) {
gst_object_unref (shader);
return NULL;
}
if (!_add_stage_to_shader (shader, state, GL_FRAGMENT_SHADER, frag)) {
gst_object_unref (shader);
return NULL;
}
if (!gst_gl_shader_link (shader, &error)) {
/* ignore failed shader compilations */
g_print ("%s", error->message);
gst_object_unref (shader);
return NULL;
}
return shader;
}
static GstGLShader *
_create_shader (GstElement * element, struct shader_state *state)
{
GstGLContext *context;
GstGLShader *shader;
g_object_get (G_OBJECT (element), "context", &context, NULL);
shader = _new_shader (context, state);
state->shader_linked = TRUE;
if (state->context)
gst_object_unref (state->context);
state->context = context;
return shader;
}
static void
_modify_shader (GstGLContext * context, struct shader_state *state)
{
GstGLShader *shader;
if (!(shader = _new_shader (context, state))) {
state->shader_linked = FALSE;
return;
}
state->shader_linked = TRUE;
g_object_set (state->shader, "shader", shader, NULL);
}
static void
_on_text_changed (GtkTextBuffer * text, struct text_view_state *state)
{
GtkTextIter start, end;
if (!state->state->context)
return;
gtk_text_buffer_get_bounds (text, &start, &end);
if (state->str)
g_free (state->str);
state->str = gtk_text_buffer_get_text (text, &start, &end, FALSE);
gst_gl_context_thread_add (state->state->context,
(GstGLContextThreadFunc) _modify_shader, state->state);
gtk_label_set_text (GTK_LABEL (state->state->label),
state->state->shader_linked ? "Success" : "Failure");
}
static GtkWidget *
_new_source_view (struct shader_state *state, GLenum type, const gchar * templ)
{
static int i = 0;
GtkWidget *scroll, *text_view;
GtkTextBuffer *text;
g_return_val_if_fail (i < MAX_SHADER_STAGES, NULL);
state->text_states[i].state = state;
state->text_states[i].type = type;
state->text_states[i].str = g_strdup (templ);
scroll = gtk_scrolled_window_new (NULL, NULL);
gtk_widget_set_size_request (scroll, 20, 20);
text_view = gtk_text_view_new ();
gtk_container_add (GTK_CONTAINER (scroll), text_view);
text = gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view));
if (state->text_states[i].str)
gtk_text_buffer_set_text (text, state->text_states[i].str, -1);
g_signal_connect (text, "changed", G_CALLBACK (_on_text_changed),
&state->text_states[i]);
state->n_stages++;
i++;
return scroll;
}
int
main (int argc, char *argv[])
{
GstElement *pipeline, *src, *upload, *shader, *sink;
GtkWidget *window, *paned, *video, *right_box, *book;
struct shader_state state = { 0, };
GstBus *bus;
#if GST_GL_HAVE_WINDOW_X11
XInitThreads ();
#endif
gst_init (&argc, &argv);
gtk_init (&argc, &argv);
loop = g_main_loop_new (NULL, FALSE);
pipeline = gst_pipeline_new (NULL);
src = gst_element_factory_make ("videotestsrc", NULL);
upload = gst_element_factory_make ("glupload", NULL);
shader = gst_element_factory_make ("glshader", NULL);
sink = gst_element_factory_make ("gtkglsink", NULL);
g_object_get (sink, "widget", &video, NULL);
g_assert (src && shader && sink);
gst_bin_add_many (GST_BIN (pipeline), src, upload, shader, sink, NULL);
g_assert (gst_element_link_many (src, upload, shader, sink, NULL));
bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
gst_bus_add_watch (bus, bus_call, loop);
gst_object_unref (bus);
state.shader = gst_object_ref (shader);
g_signal_connect (shader, "create-shader", G_CALLBACK (_create_shader),
&state);
book = gtk_notebook_new ();
/* text view inside a scroll view */
gtk_notebook_append_page (GTK_NOTEBOOK (book), _new_source_view (&state,
GL_VERTEX_SHADER, vert), gtk_label_new ("Vertex"));
gtk_notebook_append_page (GTK_NOTEBOOK (book), _new_source_view (&state,
GL_GEOMETRY_SHADER, geom), gtk_label_new ("Geometry"));
gtk_notebook_append_page (GTK_NOTEBOOK (book), _new_source_view (&state,
GL_FRAGMENT_SHADER, frag), gtk_label_new ("Fragment"));
/* status label */
state.label = gtk_label_new ("Success");
/* right side source code editor */
right_box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
gtk_box_pack_start (GTK_BOX (right_box), book, TRUE, TRUE, 0);
gtk_box_pack_start (GTK_BOX (right_box), state.label, FALSE, TRUE, 0);
paned = gtk_paned_new (GTK_ORIENTATION_HORIZONTAL);
gtk_paned_pack1 (GTK_PANED (paned), video, TRUE, FALSE);
gtk_widget_set_size_request (video, 20, 20);
gtk_paned_pack2 (GTK_PANED (paned), right_box, TRUE, FALSE);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_window_set_default_size (GTK_WINDOW (window), 640, 480);
gtk_container_add (GTK_CONTAINER (window), paned);
gtk_widget_show_all (window);
gst_element_set_state (pipeline, GST_STATE_PLAYING);
g_main_loop_run (loop);
gst_element_set_state (pipeline, GST_STATE_NULL);
/*shader strings leaked here */
/*g_free (state.str); */
gst_object_unref (state.shader);
gst_object_unref (pipeline);
return 0;
}