shader: refresh locations on shader reloads

This needs to be done after every shader pogram rebuild,
even if the uniforms and everything are unchanged.

2 files changed, 29 insertions, 23 deletions

diff --git a/src/shader.c b/src/shader.c
index bf9d325..1cadc7f 100644
--- a/src/shader.c
+++ b/src/shader.c
@@ -26,7 +26,8 @@
 typedef struct shader_t {
 	unsigned	program, refcnt;
 	unsigned	n_uniforms, n_attributes;
-	int		*uniforms, *attributes;
+	const char	**uniforms, **attributes;
+	int		*uniform_locations, *attribute_locations;
 	const char	*vs_path, *fs_path;
 	struct timespec	vs_mtime, fs_mtime;
 	
@@ -80,6 +81,14 @@ unsigned int shader_pair_new_bare(const char *vs_src, const char *fs_src)
 	return shader;
 }
 
+static void get_locations(shader_t *shader)
+{
+	for (unsigned i = 0; i < shader->n_uniforms; i++)
+		shader->uniform_locations[i] = glGetUniformLocation(shader->program, shader->uniforms[i]);
+
+	for (unsigned i = 0; i < shader->n_attributes; i++)
+		shader->attribute_locations[i] = glGetAttribLocation(shader->program, shader->attributes[i]);
+}
 
 shader_t * shader_pair_new(const char *vs_src, const char *fs_src, unsigned n_uniforms, const char **uniforms, unsigned n_attributes, const char **attributes)
 {
@@ -95,16 +104,14 @@ shader_t * shader_pair_new(const char *vs_src, const char *fs_src, unsigned n_un
 
 	shader->program = shader_pair_new_bare(vs_src, fs_src);
 	shader->refcnt++;
+	shader->uniforms = uniforms;
 	shader->n_uniforms = n_uniforms;
+	shader->attributes = attributes;
 	shader->n_attributes = n_attributes;
-	shader->uniforms = shader->locations;
-	shader->attributes = &shader->locations[n_uniforms];
+	shader->uniform_locations = shader->locations;
+	shader->attribute_locations = &shader->locations[n_uniforms];
 
-	for (unsigned i = 0; i < n_uniforms; i++)
-		shader->uniforms[i] = glGetUniformLocation(shader->program, uniforms[i]);
-
-	for (unsigned i = 0; i < n_attributes; i++)
-		shader->attributes[i] = glGetAttribLocation(shader->program, attributes[i]);
+	get_locations(shader);
 
 	return shader;
 }
@@ -170,6 +177,8 @@ int shader_reload_files(shader_t *shader)
 	free(vs_src);
 	free(fs_src);
 
+	get_locations(shader);
+
 	return ret;
 }
 
@@ -192,19 +201,16 @@ shader_t * shader_pair_new_files(const char *vs_path, const char *fs_path, unsig
 	shader->fs_path = strdup(fs_path);
 	fatal_if(!shader->fs_path, "unable to dup fs_path \"%s\"", fs_path);
 
-	(void) shader_reload_files(shader);
-
-	shader->refcnt++;
 	shader->n_uniforms = n_uniforms;
+	shader->uniforms = uniforms;
 	shader->n_attributes = n_attributes;
-	shader->uniforms = shader->locations;
-	shader->attributes = &shader->locations[n_uniforms];
+	shader->attributes = attributes;
+	shader->uniform_locations = shader->locations;
+	shader->attribute_locations = &shader->locations[n_uniforms];
 
-	for (unsigned i = 0; i < n_uniforms; i++)
-		shader->uniforms[i] = glGetUniformLocation(shader->program, uniforms[i]);
+	shader->refcnt++;
 
-	for (unsigned i = 0; i < n_attributes; i++)
-		shader->attributes[i] = glGetAttribLocation(shader->program, attributes[i]);
+	(void) shader_reload_files(shader);
 
 	return shader;
 }
@@ -233,21 +239,21 @@ shader_t * shader_free(shader_t *shader)
 }
 
 
-void shader_use(shader_t *shader, unsigned *res_n_uniforms, int **res_uniforms, unsigned *res_n_attributes, int **res_attributes)
+void shader_use(shader_t *shader, unsigned *res_n_uniforms, int **res_uniform_locations, unsigned *res_n_attributes, int **res_attribute_locations)
 {
 	assert(shader);
 
 	if (res_n_uniforms)
 		*res_n_uniforms = shader->n_uniforms;
 
-	if (res_uniforms)
-		*res_uniforms = shader->uniforms;
+	if (res_uniform_locations)
+		*res_uniform_locations = shader->uniform_locations;
 
 	if (res_n_attributes)
 		*res_n_attributes = shader->n_attributes;
 
-	if (res_attributes)
-		*res_attributes = shader->attributes;
+	if (res_attribute_locations)
+		*res_attribute_locations = shader->attribute_locations;
 
 	glUseProgram(shader->program);
 }
diff --git a/src/shader.h b/src/shader.h
index 9799e40..b52189a 100644
--- a/src/shader.h
+++ b/src/shader.h
@@ -24,7 +24,7 @@ shader_t * shader_pair_new(const char *vs_src, const char *fs_src, unsigned n_un
 shader_t * shader_pair_new_files(const char *vs_path, const char *fs_path, unsigned n_uniforms, const char **uniforms, unsigned n_attributes, const char **attributes);
 void shader_ref(shader_t *shader);
 shader_t * shader_free(shader_t *shader);
-void shader_use(shader_t *shader, unsigned *res_n_uniforms, int **res_uniforms, unsigned *res_n_attributes, int **res_attributes);
+void shader_use(shader_t *shader, unsigned *res_n_uniforms, int **res_uniform_locations, unsigned *res_n_attributes, int **res_attribute_locations);
 int shader_reload_files(shader_t *shader);
 
 #endif