custom bg-shader

1 files changed, 62 insertions, 1 deletions

diff --git a/config.c b/config.c
index 17dbf73..612a647 100644
--- a/config.c
+++ b/config.c
@@ -43,6 +43,12 @@ static bool context_is_parent(const SettingsContext *parent, const SettingsConte
 
 static void settings_copy(Settings *dest, const Settings *src) {
 	*dest = *src;
+	
+	// we only use this function before generating these
+	assert(!src->bg_shader);
+	assert(!src->bg_buffer);
+	assert(!src->bg_array);
+	
 	context_copy(&dest->context, &src->context);
 	for (u32 i = 0; i < LANG_COUNT; ++i) {
 		if (src->language_extensions[i])
@@ -59,7 +65,13 @@ static void settings_free(Settings *settings) {
 	context_free(&settings->context);
 	for (u32 i = 0; i < LANG_COUNT; ++i)
 		free(settings->language_extensions[i]);
-	memset(settings, 0, sizeof *settings);	
+	if (settings->bg_shader)
+		glDeleteProgram(settings->bg_shader);
+	if (settings->bg_buffer)
+		glDeleteBuffers(1, &settings->bg_buffer);
+	if (settings->bg_array)
+		glDeleteVertexArrays(1, &settings->bg_array);
+	memset(settings, 0, sizeof *settings);
 }
 
 static void config_part_free(ConfigPart *part) {
@@ -272,6 +284,7 @@ static OptionFloat const options_float[] = {
 };
 static OptionString const options_string[] = {
 	{"build-default-command", options_zero.build_default_command, sizeof options_zero.build_default_command, true},
+	{"bg-shader", options_zero.bg_shader_text, sizeof options_zero.bg_shader_text, true},
 };
 
 static void option_bool_set(Settings *settings, const OptionBool *opt, bool value) {
@@ -861,6 +874,54 @@ void config_parse(Ted *ted, ConfigPart **pparts) {
 		}
 	}
 	
+	arr_foreach_ptr(ted->all_settings, Settings, s) {
+		if (*s->bg_shader_text) {
+			// load bg shader
+			char vshader[] = "#version 110\n\
+	attribute vec2 v_pos;\n\
+	varying vec2 t_pos;\n\
+	void main() { \n\
+		gl_Position = vec4(v_pos * 2.0 - 1.0, 0.0, 1.0);\n\
+		t_pos = v_pos;\n\
+	}";
+			char fshader[8192];
+			strbuf_printf(fshader, "#version 110\n\
+	varying vec2 t_pos;\n\
+	uniform float t_time;\n\
+	uniform float t_save_time;\n\
+	uniform vec2 t_aspect;\n\
+	#line 1\n\
+	%s", settings->bg_shader_text);
+			s->bg_shader = gl_compile_and_link_shaders(ted->error, vshader, fshader);
+			if (s->bg_shader) {
+				GLuint bg_buffer = 0, bg_array = 0;
+				glGenBuffers(1, &bg_buffer);
+				if (gl_version_major >= 3) {
+					glGenVertexArrays(1, &bg_array);
+					glBindVertexArray(bg_array);
+				}
+				
+				s->bg_buffer = bg_buffer;
+				s->bg_array = bg_array;
+				
+				float bg_buffer_data[][2] = {
+					{0,0},
+					{1,0},
+					{1,1},
+					{0,0},
+					{1,1},
+					{0,1}
+				};
+	
+				GLuint v_pos = (GLuint)glGetAttribLocation(s->bg_shader, "v_pos");
+				glBindBuffer(GL_ARRAY_BUFFER, bg_buffer);
+				glBufferData(GL_ARRAY_BUFFER, sizeof bg_buffer_data, bg_buffer_data, GL_STATIC_DRAW);
+				glVertexAttribPointer(v_pos, 2, GL_FLOAT, 0, 2 * sizeof(float), 0);
+				glEnableVertexAttribArray(v_pos);
+			}
+		}
+	}
+	
 	arr_foreach_ptr(parts, ConfigPart, part) {
 		config_part_free(part);
 	}