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cogl: Remove the generated array size for cogl_tex_coord_in

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Under GLES2 we were defining the cogl_tex_coord_in varying as an array
with a size determined by the number of texture coordinate arrays
enabled whenever the program is used. This meant that we may have to
regenerate the shader with a different size if the shader is used with
more texture coord arrays later. However in OpenGL the equivalent
builtin varying gl_TexCoord is simply defined as:

varying vec4 gl_TexCoord[]; /* <-- no size */

GLSL is documented that if you declare an array with no size then you
can only access it with a constant index and the size of the array
will be determined by the highest index used. If you want to access it
with a non-constant expression you need to redeclare the array
yourself with a size.

We can replicate the same behaviour in our Cogl shaders by instead
declaring the cogl_tex_coord_in with no size. That way we don't have
to pass around the number of tex coord attributes enabled when we
flush a material. It also means that CoglShader can go back to
directly uploading the source string to GL when cogl_shader_source is
called so that we don't have to keep a copy of it around.

If the user wants to access cogl_tex_coord_in with a non-constant
index then they can simply redeclare the array themself. Hopefully
developers will expect to have to do this if they are accustomed to
the gl_TexCoord array.
This commit is contained in:
Neil Roberts 2010-12-02 12:27:29 +00:00
parent d2326d497a
commit 6607306a2d
13 changed files with 89 additions and 262 deletions
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2
cogl/cogl-context.c
View File

@ -262,7 +262,7 @@ cogl_create_context (void)
default_texture_data);
cogl_push_source (_context->opaque_color_pipeline);
_cogl_pipeline_flush_gl_state (_context->opaque_color_pipeline, FALSE, 0);
_cogl_pipeline_flush_gl_state (_context->opaque_color_pipeline, FALSE);
_cogl_enable (enable_flags);
_cogl_flush_face_winding ();

3
cogl/cogl-pipeline-arbfp.c
View File

@ -184,8 +184,7 @@ get_arbfp_program_state (CoglPipeline *pipeline)
static gboolean
_cogl_pipeline_backend_arbfp_start (CoglPipeline *pipeline,
int n_layers,
unsigned long pipelines_difference,
int n_tex_coord_attribs)
unsigned long pipelines_difference)
{
CoglPipelineBackendARBfpPrivate *priv;
CoglPipeline *authority;

3
cogl/cogl-pipeline-fixed.c
View File

@ -69,8 +69,7 @@ _cogl_pipeline_backend_fixed_get_max_texture_units (void)
static gboolean
_cogl_pipeline_backend_fixed_start (CoglPipeline *pipeline,
int n_layers,
unsigned long pipelines_difference,
int n_tex_coord_attribs)
unsigned long pipelines_difference)
{
CoglHandle user_program;

46
cogl/cogl-pipeline-glsl.c
View File

@ -102,15 +102,6 @@ typedef struct _GlslProgramState
GString *header, *source;
UnitState *unit_state;
/* To allow writing shaders that are portable between GLES 2 and
* OpenGL Cogl prepends a number of boilerplate #defines and
* declarations to user shaders. One of those declarations is an
* array of texture coordinate varyings, but to know how to emit the
* declaration we need to know how many texture coordinate
* attributes are in use. The boilerplate also needs to be changed
* if this increases. */
int n_tex_coord_attribs;
#ifdef HAVE_COGL_GLES2
/* The GLES2 generated program that was generated from the user
program. This is used to detect when the GLES2 backend generates
@ -286,8 +277,7 @@ link_program (GLint gl_program)
static gboolean
_cogl_pipeline_backend_glsl_start (CoglPipeline *pipeline,
int n_layers,
unsigned long pipelines_difference,
int n_tex_coord_attribs)
unsigned long pipelines_difference)
{
CoglPipelineBackendGlslPrivate *priv;
CoglPipeline *authority;
@ -320,18 +310,9 @@ _cogl_pipeline_backend_glsl_start (CoglPipeline *pipeline,
if (priv->glsl_program_state)
{
/* However if the program has changed since the last link then we do
* need to relink
*
* Also if the number of texture coordinate attributes in use has
* increased, then delete the program so we can prepend a new
* _cogl_tex_coord[] varying array declaration. */
* need to relink */
if (user_program == NULL ||
(priv->glsl_program_state->user_program_age == user_program->age
#ifdef HAVE_COGL_GLES2
&& (priv->glsl_program_state->n_tex_coord_attribs >=
n_tex_coord_attribs)
#endif
))
(priv->glsl_program_state->user_program_age == user_program->age))
return TRUE;
/* Destroy the existing program. We can't just dirty the whole
@ -382,21 +363,6 @@ _cogl_pipeline_backend_glsl_start (CoglPipeline *pipeline,
encountered it or because the user program has changed since it
was last linked */
#ifdef HAVE_COGL_GLES2
/* Find the largest count of texture coordinate attributes
* associated with each of the shaders so we can ensure a consistent
* _cogl_tex_coord[] array declaration across all of the shaders.*/
if (user_program)
for (l = user_program->attached_shaders; l; l = l->next)
{
CoglShader *shader = l->data;
n_tex_coord_attribs = MAX (shader->n_tex_coord_attribs,
n_tex_coord_attribs);
}
#endif
priv->glsl_program_state->n_tex_coord_attribs = n_tex_coord_attribs;
/* Check whether the user program contains a fragment
shader. Otherwise we need to generate one */
if (user_program)
@ -1027,9 +993,7 @@ _cogl_pipeline_backend_glsl_end (CoglPipeline *pipeline,
g_assert (shader->language == COGL_SHADER_LANGUAGE_GLSL);
_cogl_shader_compile_real (shader,
glsl_program_state->
n_tex_coord_attribs);
cogl_shader_compile (shader);
GE( glAttachShader (gl_program, shader->gl_handle) );
}
@ -1070,8 +1034,6 @@ _cogl_pipeline_backend_glsl_end (CoglPipeline *pipeline,
source_strings[1] = glsl_program_state->source->str;
_cogl_shader_set_source_with_boilerplate (shader, GL_FRAGMENT_SHADER,
glsl_program_state->
n_tex_coord_attribs,
2, /* count */
source_strings, lengths);

3
cogl/cogl-pipeline-opengl-private.h
View File

@ -150,8 +150,7 @@ _cogl_gl_use_program_wrapper (CoglHandle program);
void
_cogl_pipeline_flush_gl_state (CoglPipeline *pipeline,
gboolean skip_gl_state,
int n_tex_coord_attribs);
gboolean skip_gl_state);
#endif /* __COGL_PIPELINE_OPENGL_PRIVATE_H */

6
cogl/cogl-pipeline-opengl.c
View File

@ -1031,8 +1031,7 @@ backend_add_layer_cb (CoglPipelineLayer *layer,
*/
void
_cogl_pipeline_flush_gl_state (CoglPipeline *pipeline,
gboolean skip_gl_color,
int n_tex_coord_attribs)
gboolean skip_gl_color)
{
unsigned long pipelines_difference;
int n_layers;
@ -1135,8 +1134,7 @@ _cogl_pipeline_flush_gl_state (CoglPipeline *pipeline,
* scratch buffers here... */
if (G_UNLIKELY (!backend->start (pipeline,
n_layers,
pipelines_difference,
n_tex_coord_attribs)))
pipelines_difference)))
continue;
state.backend = backend;

3
cogl/cogl-pipeline-private.h
View File

@ -567,8 +567,7 @@ typedef struct _CoglPipelineBackend
gboolean (*start) (CoglPipeline *pipeline,
int n_layers,
unsigned long pipelines_difference,
int n_tex_coord_attribs);
unsigned long pipelines_difference);
gboolean (*add_layer) (CoglPipeline *pipeline,
CoglPipelineLayer *layer,
unsigned long layers_difference);

1
cogl/cogl-shader-boilerplate.h
View File

@ -92,6 +92,7 @@
"#endif\n" \
"\n" \
"varying vec4 _cogl_color;\n" \
"varying vec4 _cogl_tex_coord[];\n" \
"\n" \
"#define cogl_color_in _cogl_color\n" \
"#define cogl_tex_coord_in _cogl_tex_coord\n" \

6
cogl/cogl-shader-private.h
View File

@ -40,24 +40,18 @@ struct _CoglShader
{
CoglHandleObject _parent;
GLuint gl_handle;
int n_tex_coord_attribs;
CoglShaderType type;
CoglShaderLanguage language;
char *source;
};
CoglShader *_cogl_shader_pointer_from_handle (CoglHandle handle);
void
_cogl_shader_compile_real (CoglHandle handle, int n_tex_coord_attribs);
CoglShaderLanguage
_cogl_program_get_language (CoglHandle handle);
void
_cogl_shader_set_source_with_boilerplate (GLuint shader_gl_handle,
GLenum shader_gl_type,
int n_tex_coord_attribs,
GLsizei count_in,
const char **strings_in,
const GLint *lengths_in);

261
cogl/cogl-shader.c
View File

@ -101,33 +101,52 @@ cogl_create_shader (CoglShaderType type)
shader = g_slice_new (CoglShader);
shader->language = COGL_SHADER_LANGUAGE_GLSL;
shader->gl_handle = 0;
#ifdef HAVE_COGL_GLES2
shader->n_tex_coord_attribs = 0;
#endif
shader->type = type;
return _cogl_shader_handle_new (shader);
}
static void
delete_shader (CoglShader *shader)
void
_cogl_shader_set_source_with_boilerplate (GLuint shader_gl_handle,
GLenum shader_gl_type,
GLsizei count_in,
const char **strings_in,
const GLint *lengths_in)
{
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
static const char vertex_boilerplate[] = _COGL_VERTEX_SHADER_BOILERPLATE;
static const char fragment_boilerplate[] = _COGL_FRAGMENT_SHADER_BOILERPLATE;
#ifdef HAVE_COGL_GL
if (shader->language == COGL_SHADER_LANGUAGE_ARBFP)
const char **strings = g_alloca (sizeof (char *) * (count_in + 2));
GLint *lengths = g_alloca (sizeof (GLint) * (count_in + 2));
int count = 0;
GET_CONTEXT (ctx, NO_RETVAL);
if (shader_gl_type == GL_VERTEX_SHADER)
{
if (shader->gl_handle)
GE (glDeletePrograms (1, &shader->gl_handle));
strings[count] = vertex_boilerplate;
lengths[count++] = sizeof (vertex_boilerplate) - 1;
}
else if (shader_gl_type == GL_FRAGMENT_SHADER)
{
strings[count] = fragment_boilerplate;
lengths[count++] = sizeof (fragment_boilerplate) - 1;
}
memcpy (strings + count, strings_in, sizeof (char *) * count_in);
if (lengths_in)
memcpy (lengths + count, lengths_in, sizeof (GLint) * count_in);
else
#endif
{
if (shader->gl_handle)
GE (glDeleteShader (shader->gl_handle));
}
int i;
shader->gl_handle = 0;
for (i = 0; i < count_in; i++)
lengths[count + i] = -1; /* null terminated */
}
count += count_in;
GE( glShaderSource (shader_gl_handle, count,
(const char **) strings, lengths) );
}
void
@ -152,120 +171,31 @@ cogl_shader_source (CoglHandle handle,
language = COGL_SHADER_LANGUAGE_GLSL;
/* Delete the old object if the language is changing... */
if (G_UNLIKELY (language != shader->language) &&
shader->gl_handle)
delete_shader (shader);
shader->source = g_strdup (source);
shader->language = language;
}
void
cogl_shader_compile (CoglHandle handle)
{
if (G_UNLIKELY (language != shader->language))
{
#ifdef HAVE_COGL_GL
CoglShader *shader = handle;
if (shader->language == COGL_SHADER_LANGUAGE_ARBFP)
{
if (shader->gl_handle)
GE (glDeletePrograms (1, &shader->gl_handle));
}
else
#endif
if (!cogl_is_shader (handle))
return;
{
if (shader->gl_handle)
GE (glDeleteShader (shader->gl_handle));
}
}
#ifdef HAVE_COGL_GL
_cogl_shader_compile_real (shader, 0 /* ignored */);
#endif
/* XXX: For GLES2 we don't actually compile anything until the
* shader gets used so we have an opportunity to add some
* boilerplate to the shader.
*
* At the end of the day this is obviously a badly designed API
* given that we are having to lie to the user. It was a mistake to
* so thinly wrap the OpenGL shader API and the current plan is to
* replace it with a pipeline snippets API. */
}
void
_cogl_shader_set_source_with_boilerplate (GLuint shader_gl_handle,
GLenum shader_gl_type,
int n_tex_coord_attribs,
GLsizei count_in,
const char **strings_in,
const GLint *lengths_in)
{
static const char vertex_boilerplate[] = _COGL_VERTEX_SHADER_BOILERPLATE;
static const char fragment_boilerplate[] = _COGL_FRAGMENT_SHADER_BOILERPLATE;
const char **strings = g_alloca (sizeof (char *) * (count_in + 2));
GLint *lengths = g_alloca (sizeof (GLint) * (count_in + 2));
int count = 0;
#ifdef HAVE_COGL_GLES2
char *tex_coords_declaration = NULL;
#endif
GET_CONTEXT (ctx, NO_RETVAL);
if (shader_gl_type == GL_VERTEX_SHADER)
{
strings[count] = vertex_boilerplate;
lengths[count++] = sizeof (vertex_boilerplate) - 1;
}
else if (shader_gl_type == GL_FRAGMENT_SHADER)
{
strings[count] = fragment_boilerplate;
lengths[count++] = sizeof (fragment_boilerplate) - 1;
}
#ifdef HAVE_COGL_GLES2
if (n_tex_coord_attribs)
{
tex_coords_declaration =
g_strdup_printf ("varying vec2 _cogl_tex_coord[%d];\n",
n_tex_coord_attribs);
strings[count] = tex_coords_declaration;
lengths[count++] = -1; /* null terminated */
}
#endif
memcpy (strings + count, strings_in, sizeof (char *) * count_in);
if (lengths_in)
memcpy (lengths + count, lengths_in, sizeof (GLint) * count_in);
else
{
int i;
for (i = 0; i < count_in; i++)
lengths[count + i] = -1; /* null terminated */
}
count += count_in;
GE( glShaderSource (shader_gl_handle, count,
(const char **) strings, lengths) );
#ifdef HAVE_COGL_GLES2
g_free (tex_coords_declaration);
#endif
}
void
_cogl_shader_compile_real (CoglHandle handle,
int n_tex_coord_attribs)
{
CoglShader *shader = handle;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
#ifdef HAVE_COGL_GL
if (shader->language == COGL_SHADER_LANGUAGE_ARBFP)
if (language == COGL_SHADER_LANGUAGE_ARBFP)
{
#ifdef COGL_GL_DEBUG
GLenum gl_error;
#endif
if (shader->gl_handle)
return;
GE (glGenPrograms (1, &shader->gl_handle));
if (shader->gl_handle == 0)
GE (glGenPrograms (1, &shader->gl_handle));
GE (glBindProgram (GL_FRAGMENT_PROGRAM_ARB, shader->gl_handle));
@ -275,8 +205,8 @@ _cogl_shader_compile_real (CoglHandle handle,
#endif
glProgramString (GL_FRAGMENT_PROGRAM_ARB,
GL_PROGRAM_FORMAT_ASCII_ARB,
strlen (shader->source),
shader->source);
strlen (source),
source);
#ifdef COGL_GL_DEBUG
gl_error = glGetError ();
if (gl_error != GL_NO_ERROR)
@ -284,7 +214,7 @@ _cogl_shader_compile_real (CoglHandle handle,
g_warning ("%s: GL error (%d): Failed to compile ARBfp:\n%s\n%s",
G_STRLOC,
gl_error,
shader->source,
source,
glGetString (GL_PROGRAM_ERROR_STRING_ARB));
}
#endif
@ -294,16 +224,6 @@ _cogl_shader_compile_real (CoglHandle handle,
{
GLenum gl_type;
if (shader->gl_handle
#ifdef HAVE_COGL_GLES2
&& shader->n_tex_coord_attribs >= n_tex_coord_attribs
#endif
)
return;
if (shader->gl_handle)
delete_shader (shader);
switch (shader->type)
{
case COGL_SHADER_TYPE_VERTEX:
@ -317,31 +237,30 @@ _cogl_shader_compile_real (CoglHandle handle,
break;
}
shader->gl_handle = glCreateShader (gl_type);
if (!shader->gl_handle)
shader->gl_handle = glCreateShader (gl_type);
_cogl_shader_set_source_with_boilerplate (shader->gl_handle,
gl_type,
n_tex_coord_attribs,
1,
(const char **) &shader->source,
NULL);
GE (glCompileShader (shader->gl_handle));
#ifdef HAVE_COGL_GLES2
shader->n_tex_coord_attribs = n_tex_coord_attribs;
#endif
#ifdef COGL_GL_DEBUG
if (!cogl_shader_is_compiled (handle))
{
char *log = cogl_shader_get_info_log (handle);
g_warning ("Failed to compile GLSL program:\nsrc:\n%s\nerror:\n%s\n",
shader->source,
log);
}
#endif
1, &source, NULL);
}
shader->language = language;
}
void
cogl_shader_compile (CoglHandle handle)
{
CoglShader *shader;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
if (!cogl_is_shader (handle))
return;
shader = _cogl_shader_pointer_from_handle (handle);
if (shader->language == COGL_SHADER_LANGUAGE_GLSL)
GE (glCompileShader (shader->gl_handle));
}
char *
@ -369,21 +288,6 @@ cogl_shader_get_info_log (CoglHandle handle)
{
char buffer[512];
int len = 0;
/* We don't normally compile the shader when the user calls
* cogl_shader_compile() because we want to be able to add
* boilerplate code that depends on how it ends up finally being
* used.
*
* Here we force an early compile if the user is interested in
* log information to increase the chance that the log will be
* useful! We have to guess the number of texture coordinate
* attributes that may be used (normally less than 4) since that
* affects the boilerplate.
*/
if (!shader->gl_handle)
_cogl_shader_compile_real (handle, 4);
glGetShaderInfoLog (shader->gl_handle, 511, &len, buffer);
buffer[len] = '\0';
return g_strdup (buffer);
@ -426,24 +330,6 @@ cogl_shader_is_compiled (CoglHandle handle)
else
#endif
{
/* FIXME: We currently have an arbitrary limit of 4 texture
* coordinate attributes since our API means we have to add
* some boilerplate to the users GLSL program (for GLES2)
* before we actually know how many attributes are in use.
*
* 4 will probably be enough (or at least that limitation should
* be enough until we can replace this API with the pipeline
* snippets API) but if it isn't then the shader won't compile,
* through no fault of the user.
*
* To some extent this is just a symptom of bad API design; it
* was a mistake for Cogl to so thinly wrap the OpenGL shader
* API. Eventually we plan for this whole API will be deprecated
* by the pipeline snippets framework.
*/
if (!shader->gl_handle)
_cogl_shader_compile_real (handle, 4);
GE (glGetShaderiv (shader->gl_handle, GL_COMPILE_STATUS, &status));
if (status == GL_TRUE)
return TRUE;
@ -509,4 +395,3 @@ cogl_shader_is_compiled (CoglHandle handle)
}
#endif /* HAVE_COGL_GLES */

4
cogl/cogl-vertex-attribute.c
View File

@ -435,7 +435,6 @@ enable_gl_state (CoglVertexAttribute **attributes,
gboolean skip_gl_color = FALSE;
CoglPipeline *source;
CoglPipeline *copy = NULL;
int n_tex_coord_attribs = 0;
_COGL_GET_CONTEXT (ctx, COGL_INVALID_HANDLE);
@ -491,7 +490,6 @@ enable_gl_state (CoglVertexAttribute **attributes,
base + attribute->offset));
_cogl_bitmask_set (&ctx->temp_bitmask,
attribute->texture_unit, TRUE);
n_tex_coord_attribs++;
break;
case COGL_VERTEX_ATTRIBUTE_NAME_ID_POSITION_ARRAY:
enable_flags |= COGL_ENABLE_VERTEX_ARRAY;
@ -580,7 +578,7 @@ enable_gl_state (CoglVertexAttribute **attributes,
_cogl_pipeline_apply_legacy_state (source);
}
_cogl_pipeline_flush_gl_state (source, skip_gl_color, n_tex_coord_attribs);
_cogl_pipeline_flush_gl_state (source, skip_gl_color);
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;

9
cogl/cogl.c
View File

@ -770,20 +770,13 @@ cogl_begin_gl (void)
* A user should instead call cogl_set_source_color4ub() before
* cogl_begin_gl() to simplify the state flushed.
*
* XXX: note defining n_tex_coord_attribs using
* cogl_pipeline_get_n_layers is a hack, but the problem is that
* n_tex_coord_attribs is usually defined when drawing a primitive
* which isn't happening here.
*
* Maybe it would be more useful if this code did flush the
* opaque_color_pipeline and then call into cogl-pipeline-opengl.c to then
* restore all state for the material's backend back to default OpenGL
* values.
*/
pipeline = cogl_get_source ();
_cogl_pipeline_flush_gl_state (pipeline,
FALSE,
cogl_pipeline_get_n_layers (pipeline));
_cogl_pipeline_flush_gl_state (pipeline, FALSE);
if (ctx->enable_backface_culling)
enable_flags |= COGL_ENABLE_BACKFACE_CULLING;

4
cogl/cogl2-path.c
View File

@ -221,7 +221,7 @@ _cogl_path_stroke_nodes (CoglPath *path)
cogl_push_source (source);
_cogl_pipeline_flush_gl_state (source, FALSE, 0);
_cogl_pipeline_flush_gl_state (source, FALSE);
/* Disable all client texture coordinate arrays */
_cogl_bitmask_clear_all (&ctx->temp_bitmask);
@ -365,7 +365,7 @@ _cogl_add_path_to_stencil_buffer (CoglPath *path,
/* Just setup a simple pipeline that doesn't use texturing... */
cogl_push_source (ctx->stencil_pipeline);
_cogl_pipeline_flush_gl_state (ctx->stencil_pipeline, FALSE, 0);
_cogl_pipeline_flush_gl_state (ctx->stencil_pipeline, FALSE);
_cogl_enable (enable_flags);