[vlc-devel] [PATCH 25/27] doc: opengl filter: add triangle_mask sample
Romain Vimont
rom1v at videolabs.io
Thu Jun 25 14:23:12 CEST 2020
---
doc/opengl_filters/Makefile.am | 6 +
doc/opengl_filters/triangle_mask.c | 190 +++++++++++++++++++++++++++++
2 files changed, 196 insertions(+)
create mode 100644 doc/opengl_filters/triangle_mask.c
diff --git a/doc/opengl_filters/Makefile.am b/doc/opengl_filters/Makefile.am
index ca1f49a5a6..63c6054912 100644
--- a/doc/opengl_filters/Makefile.am
+++ b/doc/opengl_filters/Makefile.am
@@ -30,6 +30,12 @@ libglfilter_triangle_plugin_la_CFLAGS = $(OPENGL_FILTERS_CFLAGS)
libglfilter_triangle_plugin_la_LIBADD = $(LTLIBVLCCORE) $(LTLIBVLCGL)
libglfilter_triangle_plugin_la_LDFLAGS = $(OPENGL_FILTERS_LDFLAGS)
+OPENGL_FILTERS += libglfilter_triangle_mask_plugin.la
+libglfilter_triangle_mask_plugin_la_SOURCES = opengl_filters/triangle_mask.c
+libglfilter_triangle_mask_plugin_la_CFLAGS = $(OPENGL_FILTERS_CFLAGS)
+libglfilter_triangle_mask_plugin_la_LIBADD = $(LTLIBVLCCORE) $(LTLIBVLCGL)
+libglfilter_triangle_mask_plugin_la_LDFLAGS = $(OPENGL_FILTERS_LDFLAGS)
+
endif
lib_LTLIBRARIES = $(OPENGL_FILTERS)
diff --git a/doc/opengl_filters/triangle_mask.c b/doc/opengl_filters/triangle_mask.c
new file mode 100644
index 0000000000..9068256218
--- /dev/null
+++ b/doc/opengl_filters/triangle_mask.c
@@ -0,0 +1,190 @@
+/*****************************************************************************
+ * triangle_mask.c
+ *****************************************************************************
+ * Copyright (C) 2020 VLC authors and VideoLAN
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <assert.h>
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_modules.h>
+#include <vlc_opengl.h>
+
+#include "filter.h"
+#include "gl_api.h"
+#include "gl_common.h"
+#include "gl_util.h"
+
+struct sys {
+ GLuint program_id;
+
+ GLuint vbo;
+
+ struct {
+ GLint vertex_pos;
+ } loc;
+};
+
+static int
+Draw(struct vlc_gl_filter *filter, const struct vlc_gl_input_meta *meta)
+{
+ (void) meta;
+
+ struct sys *sys = filter->sys;
+
+ const opengl_vtable_t *vt = &filter->api->vt;
+
+ vt->UseProgram(sys->program_id);
+
+ struct vlc_gl_sampler *sampler = vlc_gl_filter_GetSampler(filter);
+ vlc_gl_sampler_Load(sampler);
+
+ vt->BindBuffer(GL_ARRAY_BUFFER, sys->vbo);
+ vt->EnableVertexAttribArray(sys->loc.vertex_pos);
+ vt->VertexAttribPointer(sys->loc.vertex_pos, 2, GL_FLOAT, GL_FALSE, 0,
+ (const void *) 0);
+
+ vt->Clear(GL_COLOR_BUFFER_BIT);
+ vt->DrawArrays(GL_TRIANGLES, 0, 3);
+
+ return VLC_SUCCESS;
+}
+
+static void
+Close(struct vlc_gl_filter *filter)
+{
+ struct sys *sys = filter->sys;
+
+ const opengl_vtable_t *vt = &filter->api->vt;
+ vt->DeleteProgram(sys->program_id);
+ vt->DeleteBuffers(1, &sys->vbo);
+
+ free(sys);
+}
+
+static vlc_gl_filter_open_fn Open;
+static int
+Open(struct vlc_gl_filter *filter, const config_chain_t *config,
+ struct vlc_gl_tex_size *size_out)
+{
+ (void) config;
+ (void) size_out;
+
+ struct sys *sys = filter->sys = malloc(sizeof(*sys));
+ if (!sys)
+ return VLC_EGENERIC;
+
+ struct vlc_gl_sampler *sampler = vlc_gl_filter_GetSampler(filter);
+
+#ifdef USE_OPENGL_ES2
+# define SHADER_VERSION "#version 100\n"
+# define FRAGMENT_SHADER_PRECISION "precision highp float;\n"
+#else
+# define SHADER_VERSION "#version 120\n"
+# define FRAGMENT_SHADER_PRECISION
+#endif
+
+ static const char *const VERTEX_SHADER =
+ SHADER_VERSION
+ "attribute vec2 vertex_pos;\n"
+ "varying vec2 tex_coords;\n"
+ "void main() {\n"
+ " gl_Position = vec4(vertex_pos, 0.0, 1.0);\n"
+ " tex_coords = vec2((vertex_pos.x + 1.0) / 2.0,\n"
+ " (vertex_pos.y + 1.0) / 2.0);\n"
+ "}\n";
+
+ static const char *const FRAGMENT_SHADER_TEMPLATE =
+ SHADER_VERSION
+ "%s\n" /* extensions */
+ FRAGMENT_SHADER_PRECISION
+ "%s\n" /* vlc_texture definition */
+ "varying vec2 tex_coords;\n"
+ "void main() {\n"
+ " gl_FragColor = vlc_texture(tex_coords);\n"
+ "}\n";
+
+ const char *extensions = sampler->shader.extensions
+ ? sampler->shader.extensions : "";
+
+ char *fragment_shader;
+ int ret = asprintf(&fragment_shader, FRAGMENT_SHADER_TEMPLATE, extensions,
+ sampler->shader.body);
+ if (ret < 0)
+ goto error;
+
+ const opengl_vtable_t *vt = &filter->api->vt;
+
+ GLuint program_id =
+ vlc_gl_BuildProgram(VLC_OBJECT(filter), vt,
+ 1, (const char **) &VERTEX_SHADER,
+ 1, (const char **) &fragment_shader);
+
+ free(fragment_shader);
+ if (!program_id)
+ goto error;
+
+ vlc_gl_sampler_FetchLocations(sampler, program_id);
+
+ sys->program_id = program_id;
+
+ sys->loc.vertex_pos = vt->GetAttribLocation(program_id, "vertex_pos");
+ assert(sys->loc.vertex_pos != -1);
+
+ vt->GenBuffers(1, &sys->vbo);
+
+ static const GLfloat vertex_pos[] = {
+ 0, 0.75,
+ -0.75, -0.75,
+ 0.9, -0.2,
+ };
+
+ vt->BindBuffer(GL_ARRAY_BUFFER, sys->vbo);
+ vt->BufferData(GL_ARRAY_BUFFER, sizeof(vertex_pos), vertex_pos,
+ GL_STATIC_DRAW);
+
+ vt->BindBuffer(GL_ARRAY_BUFFER, 0);
+
+ filter->config.msaa_level = 4;
+
+ static const struct vlc_gl_filter_ops ops = {
+ .draw = Draw,
+ .close = Close,
+ };
+ filter->ops = &ops;
+
+ return VLC_SUCCESS;
+
+error:
+ free(sys);
+ return VLC_EGENERIC;
+}
+
+vlc_module_begin()
+ set_shortname("triangle_mask")
+ set_description("OpenGL triangle mask")
+ set_category(CAT_VIDEO)
+ set_subcategory(SUBCAT_VIDEO_VFILTER)
+ set_capability("opengl filter", 0)
+ set_callback(Open)
+ add_shortcut("triangle_mask")
+vlc_module_end()
--
2.27.0
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