[Cogl] [PATCH v2] cogl-gles2-context: Append wrapper shader to user shaders
Daniel Stone
daniel at fooishbar.org
Fri Aug 17 06:37:11 PDT 2012
The SGX GLSL compiler refuses to accept shaders of the form:
void foo();
void bar() {
foo();
}
where foo is undefined at glShaderSource() time, left for definition at
link time. To work around this, simply append the wrapper shader to
user shaders, rather than building a separate shader that's always
linked with user shaders.
Signed-off-by: Daniel Stone <daniel at fooishbar.org>
---
cogl/cogl-gles2-context-private.h | 4 ---
cogl/cogl-gles2-context.c | 71 +++++++++++++------------------------
2 files changed, 25 insertions(+), 50 deletions(-)
Oops - accidentally sent out an old version that didn't quite work on ARM
due to memcpy vs. memmove comedy. Sorry!
Also, I'm not a G* person, so my apologies if all the C string handling
should actually be using some g_*() equivalents.
v2: Follow indentation style with strlen calls.
Use memmove() instead of memcpy() for overlapping strings.
diff --git a/cogl/cogl-gles2-context-private.h b/cogl/cogl-gles2-context-private.h
index f948548..5afb296 100644
--- a/cogl/cogl-gles2-context-private.h
+++ b/cogl/cogl-gles2-context-private.h
@@ -162,10 +162,6 @@ struct _CoglGLES2Context
* current */
CoglGLES2ProgramData *current_program;
- /* A shader to provide a wrapper 'main' function. A single shader is
- * used for all programs */
- GLuint wrapper_shader;
-
/* Whether the currently bound framebuffer needs flipping. This is
* used to check for changes so that we can dirty the following
* state flags */
diff --git a/cogl/cogl-gles2-context.c b/cogl/cogl-gles2-context.c
index 3585705..8568e43 100644
--- a/cogl/cogl-gles2-context.c
+++ b/cogl/cogl-gles2-context.c
@@ -64,11 +64,12 @@ static CoglUserDataKey offscreen_wrapper_key;
* a separate shader so that we can add some extra code to flip the
* rendering when rendering to an offscreen buffer */
static const char
-main_wrapper_function[] =
+main_wrapper_prelude[] =
"uniform vec4 " MAIN_WRAPPER_FLIP_UNIFORM ";\n"
- "\n"
- "void\n"
- MAIN_WRAPPER_REPLACEMENT_NAME " ();\n"
+ "\n";
+
+static const char
+main_wrapper_function[] =
"\n"
"void\n"
"main ()\n"
@@ -732,8 +733,6 @@ gl_create_program_wrapper (void)
g_hash_table_insert (gles2_ctx->program_map,
GINT_TO_POINTER (id),
data);
-
- gles2_ctx->context->glAttachShader (id, gles2_ctx->wrapper_shader);
}
return id;
@@ -829,28 +828,40 @@ gl_shader_source_wrapper (GLuint shader,
shader_data->type == GL_VERTEX_SHADER)
{
char **string_copy = g_alloca (count * sizeof (char *));
+ GLint *length_copy = g_alloca (count * sizeof (GLint));
int i;
- /* Replace any occurences of the symbol 'main' with a different
- * symbol so that we can provide our own wrapper main
- * function */
-
+ /* First, copy the shader into a new string; then, replace all
+ * instances of the symbol 'main' with our replacement symbol
+ * so we can provide our own wrapper main function; then append
+ * that wrapper function. */
for (i = 0; i < count; i++)
{
int string_length = length ? length[i] : strlen (string[i]);
+ int prelude_length = strlen (main_wrapper_prelude);
+ int wrapper_length = strlen (main_wrapper_function);
- string_copy[i] = g_memdup (string[i], string_length);
-
+ length_copy[i] = string_length + prelude_length + wrapper_length;
+ string_copy[i] = g_malloc (length_copy[i] + 1);
+ memcpy (string_copy[i], string[i], string_length);
+ string_copy[i][string_length] = '\0';
replace_token (string_copy[i],
"main",
MAIN_WRAPPER_REPLACEMENT_NAME,
string_length);
+
+ memmove (&string_copy[i][prelude_length], string_copy[i],
+ string_length);
+ memcpy (string_copy[i], main_wrapper_prelude, prelude_length);
+ memcpy (&string_copy[i][prelude_length + string_length],
+ main_wrapper_function, wrapper_length);
+ string_copy[i][length_copy[i]] = '\0';
}
gles2_ctx->context->glShaderSource (shader,
count,
(const char *const *) string_copy,
- length);
+ length_copy);
for (i = 0; i < count; i++)
g_free (string_copy[i]);
@@ -957,8 +968,7 @@ gl_get_attached_shaders_wrapper (GLuint program,
tmp_buf);
for (i = 0, count_out = 0; i < count; i++)
- if (tmp_buf[i] != gles2_ctx->wrapper_shader)
- obj[count_out++] = tmp_buf[i];
+ obj[count_out++] = tmp_buf[i];
if (count_ret)
*count_ret = count_out;
@@ -1477,8 +1487,6 @@ _cogl_gles2_context_free (CoglGLES2Context *gles2_context)
const CoglWinsysVtable *winsys;
GList *objects, *l;
- ctx->glDeleteShader (gles2_context->wrapper_shader);
-
if (gles2_context->current_program)
program_data_unref (gles2_context->current_program);
@@ -1557,33 +1565,6 @@ free_texture_object_data (CoglGLES2TextureObjectData *data)
g_slice_free (CoglGLES2TextureObjectData, data);
}
-static GLuint
-create_wrapper_shader (CoglContext *ctx)
-{
- const char *strings = main_wrapper_function;
- GLint length = sizeof (main_wrapper_function) - 1;
- GLint status;
- GLuint shader;
-
- shader = ctx->glCreateShader (GL_VERTEX_SHADER);
- ctx->glShaderSource (shader, 1, &strings, &length);
- ctx->glCompileShader (shader);
- ctx->glGetShaderiv (shader, GL_COMPILE_STATUS, &status);
-
- if (!status)
- {
- char buf[512];
-
- ctx->glGetShaderInfoLog (shader,
- sizeof (buf),
- NULL, /* length */
- buf);
- g_warning ("Compiling wrapper shader failed:\n%s", buf);
- }
-
- return shader;
-}
-
CoglGLES2Context *
cogl_gles2_context_new (CoglContext *ctx, GError **error)
{
@@ -1639,8 +1620,6 @@ cogl_gles2_context_new (CoglContext *ctx, GError **error)
#undef COGL_EXT_FUNCTION
#undef COGL_EXT_END
- gles2_ctx->wrapper_shader = create_wrapper_shader (ctx);
-
gles2_ctx->vtable->glBindFramebuffer = gl_bind_framebuffer_wrapper;
gles2_ctx->vtable->glReadPixels = gl_read_pixels_wrapper;
gles2_ctx->vtable->glCopyTexImage2D = gl_copy_tex_image_2d_wrapper;
--
1.7.10.4
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