custom shader texture

6 files changed, 111 insertions, 7 deletions

diff --git a/config.c b/config.c
index 3ac9b18..1265eaf 100644
--- a/config.c
+++ b/config.c
@@ -45,6 +45,7 @@ static void settings_copy(Settings *dest, const Settings *src) {
 	*dest = *src;
 	
 	gl_rc_sab_incref(dest->bg_shader);
+	gl_rc_texture_incref(dest->bg_texture);
 	
 	context_copy(&dest->context, &src->context);
 	for (u32 i = 0; i < LANG_COUNT; ++i) {
@@ -258,7 +259,7 @@ static OptionU8 const options_u8[] = {
 	{"tags-max-depth", &options_zero.tags_max_depth, 1, 100, false},
 };
 static OptionU16 const options_u16[] = {
-	{"text-size", &options_zero.text_size, TEXT_SIZE_MIN, TEXT_SIZE_MAX, true},
+	{"text-size", &options_zero.text_size, TEXT_SIZE_MIN, TEXT_SIZE_MAX, false},
 	{"max-menu-width", &options_zero.max_menu_width, 10, U16_MAX, false},
 	{"error-display-time", &options_zero.error_display_time, 0, U16_MAX, false},
 };
@@ -573,10 +574,11 @@ void main() { \n\
 uniform float t_time;\n\
 uniform float t_save_time;\n\
 uniform vec2 t_aspect;\n\
+uniform sampler2D t_texture;\n\
 #line 1\n\
 %s", s->bg_shader_text);
 	
-	if (s->bg_shader) gl_rc_sab_decref(&s->bg_shader);
+	gl_rc_sab_decref(&s->bg_shader);
 	
 	GLuint shader = gl_compile_and_link_shaders(ted->error, vshader, fshader);
 	if (shader) {
@@ -607,6 +609,26 @@ uniform vec2 t_aspect;\n\
 	}
 }
 
+static void settings_load_bg_texture(Ted *ted, Settings *s) {
+	gl_rc_texture_decref(&s->bg_texture);
+	
+	const char *path = s->bg_shader_image;
+	char expanded[TED_PATH_MAX];
+	expanded[0] = '\0';
+	if (path[0] == '~') {
+		strbuf_cpy(expanded, ted->home);
+		++path;
+	}
+	strbuf_cat(expanded, path);
+	
+	GLuint texture = gl_load_texture_from_image(expanded);
+	if (texture) {
+		s->bg_texture = gl_rc_texture_new(texture);
+	} else {
+		ted_seterr(ted, "Couldn't load image %s", path);
+	}
+}
+
 // reads a single "line" of the config file, but it may include a multiline string,
 // so it may read multiple lines.
 static void config_parse_line(ConfigReader *cfg, Settings *settings, const ConfigPart *part, char **pline) {
@@ -832,9 +854,10 @@ static void config_parse_line(ConfigReader *cfg, Settings *settings, const Confi
 			}
 		}
 		
-		if (streq(key, "bg-shader")) {
+		if (streq(key, "bg-shader"))
 			settings_load_bg_shader(ted, settings);
-		}
+		if (streq(key, "bg-texture"))
+			settings_load_bg_texture(ted, settings);
 		
 		// this is probably a bad idea:
 		//if (!recognized)
@@ -952,6 +975,7 @@ void config_free(Ted *ted) {
 		for (u32 i = 0; i < LANG_COUNT; ++i)
 			free(settings->language_extensions[i]);
 		gl_rc_sab_decref(&settings->bg_shader);
+		gl_rc_texture_decref(&settings->bg_texture);
 	}
 	
 	
diff --git a/gl.c b/gl.c
index c16d252..1c41d54 100644
--- a/gl.c
+++ b/gl.c
@@ -5,6 +5,7 @@
 	do(DRAWARRAYS, DrawArrays)\
 	do(GENTEXTURES, GenTextures)\
 	do(DELETETEXTURES, DeleteTextures)\
+	do(GENERATEMIPMAP, GenerateMipmap)\
 	do(TEXIMAGE2D, TexImage2D)\
 	do(BINDTEXTURE, BindTexture)\
 	do(TEXPARAMETERI, TexParameteri)\
@@ -87,6 +88,29 @@ void gl_rc_sab_decref(GlRcSAB **ps) {
 	*ps = NULL;
 }
 
+GlRcTexture *gl_rc_texture_new(GLuint texture) {
+	GlRcTexture *t = calloc(1, sizeof *t);
+	t->ref_count = 1;
+	t->texture = texture;
+	return t;
+}
+
+void gl_rc_texture_incref(GlRcTexture *t) {
+	if (!t) return;
+	++t->ref_count;
+}
+
+void gl_rc_texture_decref(GlRcTexture **pt) {
+	GlRcTexture *t = *pt;
+	if (!t) return;
+	if (--t->ref_count == 0) {
+		debug_println("Delete texture %u", t->texture);
+		glDeleteTextures(1, &t->texture);
+		free(t);
+	}
+	*pt = NULL;
+}
+
 // set by main()
 static int gl_version_major;
 static int gl_version_minor;
@@ -305,3 +329,33 @@ static void gl_geometry_draw(void) {
 	
 	arr_clear(gl_geometry_triangles);
 }
+
+static GLuint gl_load_texture_from_image(const char *path) {
+	GLuint texture = 0;
+	int w=0, h=0, n=0;
+	unsigned char *data = stbi_load(path, &w, &h, &n, 4);
+	if (data && w > 0 && h > 0) {
+		size_t bytes_per_row = (size_t)w * 4;
+		unsigned char *tempbuf = calloc(1, bytes_per_row);
+		// flip image vertically
+		for (int y = 0; y < h/2; ++y) {
+			int y2 = h-1-y;
+			unsigned char *row1 = &data[y*w*4];
+			unsigned char *row2 = &data[y2*w*4];
+			memcpy(tempbuf, row1, bytes_per_row);
+			memcpy(row1, row2, bytes_per_row);
+			memcpy(row2, tempbuf, bytes_per_row);
+		}
+		free(tempbuf);
+		
+		glGenTextures(1, &texture);
+		glBindTexture(GL_TEXTURE_2D, texture);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+		free(data);
+	}
+	return texture;
+}
diff --git a/main.c b/main.c
index 8fc0ca3..dbc49d5 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,5 @@
 /* 
 FUTURE FEATURES:
-- custom shaders texture
 - config variables
 - plugins?
 */
@@ -811,6 +810,15 @@ int main(int argc, char **argv) {
 				glUniform1f(glGetUniformLocation(shader, "t_time"), (float)fmod(t - start_time, 3600));
 				glUniform2f(glGetUniformLocation(shader, "t_aspect"), (float)window_width / (float)window_height, 1);
 				glUniform1f(glGetUniformLocation(shader, "t_save_time"), (float)(t - ted->last_save_time));
+				if (s->bg_texture) {
+					GLuint texture = s->bg_texture->texture;
+					glActiveTexture(GL_TEXTURE0);
+					glBindTexture(GL_TEXTURE_2D, texture);
+					glUniform1i(glGetUniformLocation(shader, "t_texture"), 0);
+				} else {
+					glActiveTexture(GL_TEXTURE0);
+					glBindTexture(GL_TEXTURE_2D, 0);
+				}
 				glBindBuffer(GL_ARRAY_BUFFER, buffer);
 				if (!array) {
 					GLuint v_pos = (GLuint)glGetAttribLocation(shader, "v_pos");
diff --git a/ted.cfg b/ted.cfg
index 0c142b1..4b815f6 100644
--- a/ted.cfg
+++ b/ted.cfg
@@ -42,6 +42,7 @@ regenerate-tags-if-not-found = yes
 #     t_aspect - (window_width / window_height, 1)
 #     t_time - current time in seconds, modulo 3600
 #     t_save_time - time since last save, in seconds.
+#     t_texture - a texture, made with your choice of image
 # if you want your shader supported no matter what, only use stuff from GLSL version 110.
 #  on non-ancient computers, you should be able to use GLSL version 130.
 # bg-shader = "void main() {
@@ -51,6 +52,9 @@ regenerate-tags-if-not-found = yes
 # 	vec4 color = vec4(r, g, 1.0 - t_save_time, 0.2);
 # 	gl_FragColor = clamp(color, 0.0, 1.0);
 # }"
+# here's an example using a texture:
+# bg-texture = "/path/to/my/cool/picture.jpg" (or .png, .gif, .bmp)
+# bg-shader = "void main() { gl_FragColor = texture2D(t_texture, t_pos) * vec4(1.0,1.0,1.0,0.2); }"
 
 [keyboard]
 # motion and selection
diff --git a/ted.h b/ted.h
index bbd2d48..3db5a3c 100644
--- a/ted.h
+++ b/ted.h
@@ -143,9 +143,21 @@ typedef struct {
 	char *path; // these settings apply to all paths which start with this string, or all paths if path=NULL
 } SettingsContext;
 
-// shader-array-buffer combo.
 // need to use refcounting for this because of Settings.
-// (we copy parent settings to children)
+// => we copy parent settings to children
+// e.g.
+//     [core]
+//     bg-texture = "blablabla.png"
+//     [Javascript.core]
+//     some random shit
+// the main Settings' bg_texture will get copied to javascript's Settings,
+// so we need to be extra careful about when we delete textures.
+typedef struct {
+	u32 ref_count;
+	u32 texture;
+} GlRcTexture;
+
+// shader-array-buffer combo.
 typedef struct {
 	u32 ref_count;
 	u32 shader;
@@ -177,6 +189,7 @@ typedef struct {
 	u8 scrolloff;
 	u8 tags_max_depth;
 	GlRcSAB *bg_shader;
+	GlRcTexture *bg_texture;
 	char bg_shader_text[4096];
 	char bg_shader_image[TED_PATH_MAX];
 	char build_default_command[256];
diff --git a/util.c b/util.c
index 57b54da..cee9cc3 100644
--- a/util.c
+++ b/util.c
@@ -150,6 +150,7 @@ static void str_cpy(char *dst, size_t dst_sz, char const *src) {
 }
 
 #define strbuf_cpy(dst, src) str_cpy(dst, sizeof dst, src)
+#define strbuf_cat(dst, src) str_cat(dst, sizeof dst, src)
 
 // advances str to the start of the next UTF8 character
 static void utf8_next_char_const(char const **str) {