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mutter/cogl/cogl-blend-string.c
Neil Roberts 2616ae0fa9 Add a GL 3 driver 
This adds a new CoglDriver for GL 3 called COGL_DRIVER_GL3. When
requested, the GLX, EGL and SDL2 winsyss will set the necessary
attributes to request a forward-compatible core profile 3.1 context.
That means it will have no deprecated features.

To simplify the explosion of checks for specific combinations of
context->driver, many of these conditionals have now been replaced
with private feature flags that are checked instead. The GL and GLES
drivers now initialise these private feature flags depending on which
driver is used.

The fixed function backends now explicitly check whether the fixed
function private feature is available which means the GL3 driver will
fall back to always using the GLSL progend. Since Rob's latest patches
the GLSL progend no longer uses any fixed function API anyway so it
should just work.

The driver is currently lower priority than COGL_DRIVER_GL so it will
not be used unless it is specificly requested. We may want to change
this priority at some point because apparently Mesa can make some
memory savings if a core profile context is used.

In GL 3, getting the combined extensions string with glGetString is
deprecated so this patch changes it to use glGetStringi to build up an
array of extensions instead. _cogl_context_get_gl_extensions now
returns this array instead of trying to return a const string. The
caller is expected to free the array.

Some issues with this patch:

• GL 3 does not support GL_ALPHA format textures. We should probably
  make this a feature flag or something. Cogl uses this to render text
  which currently just throws a GL error and breaks so it's pretty
  important to do something about this before considering the GL3
  driver to be stable.

• GL 3 doesn't support client side vertex buffers. This probably
  doesn't matter because CoglBuffer won't normally use malloc'd
  buffers if VBOs are available, but it might but worth making
  malloc'd buffers a private feature and forcing it not to use them.

• GL 3 doesn't support the default vertex array object. This patch
  just makes it create and bind a single non-default vertex array
  object which gets used just like the normal default object. Ideally
  it would be good to use vertex array objects properly and attach
  them to a CoglPrimitive to cache the state.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 66c9db993595b3a22e63f4c201ea468bc9b88cb6)
2013-01-22 17:48:01 +00:00

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2009 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include <glib.h>
#include "cogl-internal.h"
#include "cogl-context-private.h"
#include "cogl-debug.h"
#include "cogl-blend-string.h"
#include "cogl-error-private.h"
typedef enum _ParserState
{
PARSER_STATE_EXPECT_DEST_CHANNELS,
PARSER_STATE_SCRAPING_DEST_CHANNELS,
PARSER_STATE_EXPECT_FUNCTION_NAME,
PARSER_STATE_SCRAPING_FUNCTION_NAME,
PARSER_STATE_EXPECT_ARG_START,
PARSER_STATE_EXPECT_STATEMENT_END
} ParserState;
typedef enum _ParserArgState
{
PARSER_ARG_STATE_START,
PARSER_ARG_STATE_EXPECT_MINUS,
PARSER_ARG_STATE_EXPECT_COLOR_SRC_NAME,
PARSER_ARG_STATE_SCRAPING_COLOR_SRC_NAME,
PARSER_ARG_STATE_MAYBE_COLOR_MASK,
PARSER_ARG_STATE_SCRAPING_MASK,
PARSER_ARG_STATE_MAYBE_MULT,
PARSER_ARG_STATE_EXPECT_OPEN_PAREN,
PARSER_ARG_STATE_EXPECT_FACTOR,
PARSER_ARG_STATE_MAYBE_SRC_ALPHA_SATURATE,
PARSER_ARG_STATE_MAYBE_MINUS,
PARSER_ARG_STATE_EXPECT_CLOSE_PAREN,
PARSER_ARG_STATE_EXPECT_END
} ParserArgState;
#define DEFINE_COLOR_SOURCE(NAME, NAME_LEN) \
{/*.type = */COGL_BLEND_STRING_COLOR_SOURCE_ ## NAME, \
/*.name = */#NAME, \
/*.name_len = */NAME_LEN}
static CoglBlendStringColorSourceInfo blending_color_sources[] = {
DEFINE_COLOR_SOURCE (SRC_COLOR, 9),
DEFINE_COLOR_SOURCE (DST_COLOR, 9),
DEFINE_COLOR_SOURCE (CONSTANT, 8)
};
static CoglBlendStringColorSourceInfo tex_combine_color_sources[] = {
DEFINE_COLOR_SOURCE (TEXTURE, 7),
/* DEFINE_COLOR_SOURCE (TEXTURE_N, *) - handled manually */
DEFINE_COLOR_SOURCE (PRIMARY, 7),
DEFINE_COLOR_SOURCE (CONSTANT, 8),
DEFINE_COLOR_SOURCE (PREVIOUS, 8)
};
static CoglBlendStringColorSourceInfo tex_combine_texture_n_color_source = {
/*.type = */COGL_BLEND_STRING_COLOR_SOURCE_TEXTURE_N,
/*.name = */"TEXTURE_N",
/*.name_len = */0
};
#undef DEFINE_COLOR_SOURCE
#define DEFINE_FUNCTION(NAME, NAME_LEN, ARGC) \
{ /*.type = */COGL_BLEND_STRING_FUNCTION_ ## NAME, \
/*.name = */#NAME, \
/*.name_len = */NAME_LEN, \
/*.argc = */ARGC }
/* NB: These must be sorted so any name that's a subset of another
* comes later than the longer name. */
static CoglBlendStringFunctionInfo tex_combine_functions[] = {
DEFINE_FUNCTION (REPLACE, 7, 1),
DEFINE_FUNCTION (MODULATE, 8, 2),
DEFINE_FUNCTION (ADD_SIGNED, 10, 2),
DEFINE_FUNCTION (ADD, 3, 2),
DEFINE_FUNCTION (INTERPOLATE, 11, 3),
DEFINE_FUNCTION (SUBTRACT, 8, 2),
DEFINE_FUNCTION (DOT3_RGBA, 9, 2),
DEFINE_FUNCTION (DOT3_RGB, 8, 2)
};
static CoglBlendStringFunctionInfo blend_functions[] = {
DEFINE_FUNCTION (ADD, 3, 2)
};
#undef DEFINE_FUNCTION
uint32_t
cogl_blend_string_error_quark (void)
{
return g_quark_from_static_string ("cogl-blend-string-error-quark");
}
void
_cogl_blend_string_split_rgba_statement (CoglBlendStringStatement *statement,
CoglBlendStringStatement *rgb,
CoglBlendStringStatement *a)
{
int i;
memcpy (rgb, statement, sizeof (CoglBlendStringStatement));
memcpy (a, statement, sizeof (CoglBlendStringStatement));
rgb->mask = COGL_BLEND_STRING_CHANNEL_MASK_RGB;
a->mask = COGL_BLEND_STRING_CHANNEL_MASK_ALPHA;
for (i = 0; i < statement->function->argc; i++)
{
CoglBlendStringArgument *arg = &statement->args[i];
CoglBlendStringArgument *rgb_arg = &rgb->args[i];
CoglBlendStringArgument *a_arg = &a->args[i];
if (arg->source.mask == COGL_BLEND_STRING_CHANNEL_MASK_RGBA)
{
rgb_arg->source.mask = COGL_BLEND_STRING_CHANNEL_MASK_RGB;
a_arg->source.mask = COGL_BLEND_STRING_CHANNEL_MASK_ALPHA;
}
if (arg->factor.is_color &&
arg->factor.source.mask == COGL_BLEND_STRING_CHANNEL_MASK_RGBA)
{
rgb_arg->factor.source.mask = COGL_BLEND_STRING_CHANNEL_MASK_RGB;
a_arg->factor.source.mask = COGL_BLEND_STRING_CHANNEL_MASK_ALPHA;
}
}
}
static CoglBool
validate_tex_combine_statements (CoglBlendStringStatement *statements,
int n_statements,
CoglError **error)
{
int i, j;
const char *error_string;
CoglBlendStringError detail = COGL_BLEND_STRING_ERROR_INVALID_ERROR;
for (i = 0; i < n_statements; i++)
{
for (j = 0; j < statements[i].function->argc; j++)
{
CoglBlendStringArgument *arg = &statements[i].args[j];
if (arg->source.is_zero)
{
error_string = "You can't use the constant '0' as a texture "
"combine argument";
goto error;
}
if (!arg->factor.is_one)
{
error_string = "Argument factors are only relevant to blending "
"not texture combining";
goto error;
}
}
}
return TRUE;
error:
_cogl_set_error (error,
COGL_BLEND_STRING_ERROR,
detail,
"Invalid texture combine string: %s",
error_string);
if (COGL_DEBUG_ENABLED (COGL_DEBUG_BLEND_STRINGS))
{
g_debug ("Invalid texture combine string: %s",
error_string);
}
return FALSE;
}
static CoglBool
validate_blend_statements (CoglBlendStringStatement *statements,
int n_statements,
CoglError **error)
{
int i, j;
const char *error_string;
CoglBlendStringError detail = COGL_BLEND_STRING_ERROR_INVALID_ERROR;
_COGL_GET_CONTEXT (ctx, 0);
if (n_statements == 2 &&
!ctx->glBlendEquationSeparate &&
statements[0].function->type != statements[1].function->type)
{
error_string = "Separate blend functions for the RGB an A "
"channels isn't supported by the driver";
detail = COGL_BLEND_STRING_ERROR_GPU_UNSUPPORTED_ERROR;
goto error;
}
for (i = 0; i < n_statements; i++)
for (j = 0; j < statements[i].function->argc; j++)
{
CoglBlendStringArgument *arg = &statements[i].args[j];
if (arg->source.is_zero)
continue;
if ((j == 0 &&
arg->source.info->type !=
COGL_BLEND_STRING_COLOR_SOURCE_SRC_COLOR)
|| (j == 1 &&
arg->source.info->type !=
COGL_BLEND_STRING_COLOR_SOURCE_DST_COLOR))
{
error_string = "For blending you must always use SRC_COLOR "
"for arg0 and DST_COLOR for arg1";
goto error;
}
if (!(ctx->private_feature_flags &
COGL_PRIVATE_FEATURE_BLEND_CONSTANT) &&
arg->factor.is_color &&
(arg->factor.source.info->type ==
COGL_BLEND_STRING_COLOR_SOURCE_CONSTANT))
{
error_string = "Driver doesn't support constant blend factors";
detail = COGL_BLEND_STRING_ERROR_GPU_UNSUPPORTED_ERROR;
goto error;
}
}
return TRUE;
error:
_cogl_set_error (error,
COGL_BLEND_STRING_ERROR,
detail,
"Invalid blend string: %s",
error_string);
return FALSE;
}
static CoglBool
validate_statements_for_context (CoglBlendStringStatement *statements,
int n_statements,
CoglBlendStringContext context,
CoglError **error)
{
const char *error_string;
if (n_statements == 1)
{
if (statements[0].mask == COGL_BLEND_STRING_CHANNEL_MASK_ALPHA)
{
error_string = "You need to also give a blend statement for the RGB"
"channels";
goto error;
}
else if (statements[0].mask == COGL_BLEND_STRING_CHANNEL_MASK_RGB)
{
error_string = "You need to also give a blend statement for the "
"Alpha channel";
goto error;
}
}
if (context == COGL_BLEND_STRING_CONTEXT_BLENDING)
return validate_blend_statements (statements, n_statements, error);
else
return validate_tex_combine_statements (statements, n_statements, error);
error:
_cogl_set_error (error,
COGL_BLEND_STRING_ERROR,
COGL_BLEND_STRING_ERROR_INVALID_ERROR,
"Invalid %s string: %s",
context == COGL_BLEND_STRING_CONTEXT_BLENDING ?
"blend" : "texture combine",
error_string);
if (COGL_DEBUG_ENABLED (COGL_DEBUG_BLEND_STRINGS))
{
g_debug ("Invalid %s string: %s",
context == COGL_BLEND_STRING_CONTEXT_BLENDING ?
"blend" : "texture combine",
error_string);
}
return FALSE;
}
static void
print_argument (CoglBlendStringArgument *arg)
{
const char *mask_names[] = {
"RGB",
"A",
"RGBA"
};
g_print (" Arg:\n");
g_print (" is zero = %s\n", arg->source.is_zero ? "yes" : "no");
if (!arg->source.is_zero)
{
g_print (" color source = %s\n", arg->source.info->name);
g_print (" one minus = %s\n", arg->source.one_minus ? "yes" : "no");
g_print (" mask = %s\n", mask_names[arg->source.mask]);
g_print (" texture = %d\n", arg->source.texture);
g_print ("\n");
g_print (" factor is_one = %s\n", arg->factor.is_one ? "yes" : "no");
g_print (" factor is_src_alpha_saturate = %s\n",
arg->factor.is_src_alpha_saturate ? "yes" : "no");
g_print (" factor is_color = %s\n", arg->factor.is_color ? "yes" : "no");
if (arg->factor.is_color)
{
g_print (" factor color:is zero = %s\n",
arg->factor.source.is_zero ? "yes" : "no");
g_print (" factor color:color source = %s\n",
arg->factor.source.info->name);
g_print (" factor color:one minus = %s\n",
arg->factor.source.one_minus ? "yes" : "no");
g_print (" factor color:mask = %s\n",
mask_names[arg->factor.source.mask]);
g_print (" factor color:texture = %d\n",
arg->factor.source.texture);
}
}
}
static void
print_statement (int num, CoglBlendStringStatement *statement)
{
const char *mask_names[] = {
"RGB",
"A",
"RGBA"
};
int i;
g_print ("Statement %d:\n", num);
g_print (" Destination channel mask = %s\n",
mask_names[statement->mask]);
g_print (" Function = %s\n", statement->function->name);
for (i = 0; i < statement->function->argc; i++)
print_argument (&statement->args[i]);
}
static const CoglBlendStringFunctionInfo *
get_function_info (const char *mark,
const char *p,
CoglBlendStringContext context)
{
size_t len = p - mark;
CoglBlendStringFunctionInfo *functions;
size_t array_len;
int i;
if (context == COGL_BLEND_STRING_CONTEXT_BLENDING)
{
functions = blend_functions;
array_len = G_N_ELEMENTS (blend_functions);
}
else
{
functions = tex_combine_functions;
array_len = G_N_ELEMENTS (tex_combine_functions);
}
for (i = 0; i < array_len; i++)
{
if (len >= functions[i].name_len
&& strncmp (mark, functions[i].name, functions[i].name_len) == 0)
return &functions[i];
}
return NULL;
}
static const CoglBlendStringColorSourceInfo *
get_color_src_info (const char *mark,
const char *p,
CoglBlendStringContext context)
{
size_t len = p - mark;
CoglBlendStringColorSourceInfo *sources;
size_t array_len;
int i;
if (context == COGL_BLEND_STRING_CONTEXT_BLENDING)
{
sources = blending_color_sources;
array_len = G_N_ELEMENTS (blending_color_sources);
}
else
{
sources = tex_combine_color_sources;
array_len = G_N_ELEMENTS (tex_combine_color_sources);
}
if (len >= 8 &&
strncmp (mark, "TEXTURE_", 8) == 0 &&
g_ascii_isdigit (mark[8]))
{
return &tex_combine_texture_n_color_source;
}
for (i = 0; i < array_len; i++)
{
if (len >= sources[i].name_len
&& strncmp (mark, sources[i].name, sources[i].name_len) == 0)
return &sources[i];
}
return NULL;
}
static CoglBool
is_symbol_char (const char c)
{
return (g_ascii_isalpha (c) || c == '_') ? TRUE : FALSE;
}
static CoglBool
is_alphanum_char (const char c)
{
return (g_ascii_isalnum (c) || c == '_') ? TRUE : FALSE;
}
static CoglBool
parse_argument (const char *string, /* original user string */
const char **ret_p, /* start of argument IN:OUT */
const CoglBlendStringStatement *statement,
int current_arg,
CoglBlendStringArgument *arg, /* OUT */
CoglBlendStringContext context,
CoglError **error)
{
const char *p = *ret_p;
const char *mark = NULL;
const char *error_string = NULL;
ParserArgState state = PARSER_ARG_STATE_START;
CoglBool parsing_factor = FALSE;
CoglBool implicit_factor_brace;
arg->source.is_zero = FALSE;
arg->source.info = NULL;
arg->source.texture = 0;
arg->source.one_minus = FALSE;
arg->source.mask = statement->mask;
arg->factor.is_one = FALSE;
arg->factor.is_color = FALSE;
arg->factor.is_src_alpha_saturate = FALSE;
arg->factor.source.is_zero = FALSE;
arg->factor.source.info = NULL;
arg->factor.source.texture = 0;
arg->factor.source.one_minus = FALSE;
arg->factor.source.mask = statement->mask;
do
{
if (g_ascii_isspace (*p))
continue;
if (*p == '\0')
{
error_string = "Unexpected end of string while parsing argument";
goto error;
}
switch (state)
{
case PARSER_ARG_STATE_START:
if (*p == '1')
state = PARSER_ARG_STATE_EXPECT_MINUS;
else if (*p == '0')
{
arg->source.is_zero = TRUE;
state = PARSER_ARG_STATE_EXPECT_END;
}
else
{
p--; /* backtrack */
state = PARSER_ARG_STATE_EXPECT_COLOR_SRC_NAME;
}
continue;
case PARSER_ARG_STATE_EXPECT_MINUS:
if (*p != '-')
{
error_string = "expected a '-' following the 1";
goto error;
}
arg->source.one_minus = TRUE;
state = PARSER_ARG_STATE_EXPECT_COLOR_SRC_NAME;
continue;
case PARSER_ARG_STATE_EXPECT_COLOR_SRC_NAME:
if (!is_symbol_char (*p))
{
error_string = "expected a color source name";
goto error;
}
state = PARSER_ARG_STATE_SCRAPING_COLOR_SRC_NAME;
mark = p;
if (parsing_factor)
arg->factor.is_color = TRUE;
/* fall through */
case PARSER_ARG_STATE_SCRAPING_COLOR_SRC_NAME:
if (!is_symbol_char (*p))
{
CoglBlendStringColorSource *source =
parsing_factor ? &arg->factor.source : &arg->source;
source->info = get_color_src_info (mark, p, context);
if (!source->info)
{
error_string = "Unknown color source name";
goto error;
}
if (source->info->type ==
COGL_BLEND_STRING_COLOR_SOURCE_TEXTURE_N)
{
char *endp;
source->texture =
strtoul (&mark[strlen ("TEXTURE_")], &endp, 10);
if (mark == endp)
{
error_string = "invalid texture number given with "
"TEXTURE_N color source";
goto error;
}
p = endp;
}
state = PARSER_ARG_STATE_MAYBE_COLOR_MASK;
}
else
continue;
/* fall through */
case PARSER_ARG_STATE_MAYBE_COLOR_MASK:
if (*p != '[')
{
p--; /* backtrack */
if (!parsing_factor)
state = PARSER_ARG_STATE_MAYBE_MULT;
else
state = PARSER_ARG_STATE_EXPECT_END;
continue;
}
state = PARSER_ARG_STATE_SCRAPING_MASK;
mark = p;
/* fall through */
case PARSER_ARG_STATE_SCRAPING_MASK:
if (*p == ']')
{
size_t len = p - mark;
CoglBlendStringColorSource *source =
parsing_factor ? &arg->factor.source : &arg->source;
if (len == 5 && strncmp (mark, "[RGBA", len) == 0)
{
if (statement->mask != COGL_BLEND_STRING_CHANNEL_MASK_RGBA)
{
error_string = "You can't use an RGBA color mask if the "
"statement hasn't also got an RGBA= mask";
goto error;
}
source->mask = COGL_BLEND_STRING_CHANNEL_MASK_RGBA;
}
else if (len == 4 && strncmp (mark, "[RGB", len) == 0)
source->mask = COGL_BLEND_STRING_CHANNEL_MASK_RGB;
else if (len == 2 && strncmp (mark, "[A", len) == 0)
source->mask = COGL_BLEND_STRING_CHANNEL_MASK_ALPHA;
else
{
error_string = "Expected a channel mask of [RGBA]"
"[RGB] or [A]";
goto error;
}
if (parsing_factor)
state = PARSER_ARG_STATE_EXPECT_CLOSE_PAREN;
else
state = PARSER_ARG_STATE_MAYBE_MULT;
}
continue;
case PARSER_ARG_STATE_EXPECT_OPEN_PAREN:
if (*p != '(')
{
if (is_alphanum_char (*p))
{
p--; /* compensate for implicit brace and ensure this
* char gets considered part of the blend factor */
implicit_factor_brace = TRUE;
}
else
{
error_string = "Expected '(' around blend factor or alpha "
"numeric character for blend factor name";
goto error;
}
}
else
implicit_factor_brace = FALSE;
parsing_factor = TRUE;
state = PARSER_ARG_STATE_EXPECT_FACTOR;
continue;
case PARSER_ARG_STATE_EXPECT_FACTOR:
if (*p == '1')
state = PARSER_ARG_STATE_MAYBE_MINUS;
else if (*p == '0')
{
arg->source.is_zero = TRUE;
state = PARSER_ARG_STATE_EXPECT_CLOSE_PAREN;
}
else
{
state = PARSER_ARG_STATE_MAYBE_SRC_ALPHA_SATURATE;
mark = p;
}
continue;
case PARSER_ARG_STATE_MAYBE_SRC_ALPHA_SATURATE:
if (!is_symbol_char (*p))
{
size_t len = p - mark;
if (len >= strlen ("SRC_ALPHA_SATURATE") &&
strncmp (mark, "SRC_ALPHA_SATURATE", len) == 0)
{
arg->factor.is_src_alpha_saturate = TRUE;
state = PARSER_ARG_STATE_EXPECT_CLOSE_PAREN;
}
else
{
state = PARSER_ARG_STATE_EXPECT_COLOR_SRC_NAME;
p = mark - 1; /* backtrack */
}
}
continue;
case PARSER_ARG_STATE_MAYBE_MINUS:
if (*p == '-')
{
if (implicit_factor_brace)
{
error_string = "Expected ( ) braces around blend factor with "
"a subtraction";
goto error;
}
arg->factor.source.one_minus = TRUE;
state = PARSER_ARG_STATE_EXPECT_COLOR_SRC_NAME;
}
else
{
arg->factor.is_one = TRUE;
state = PARSER_ARG_STATE_EXPECT_CLOSE_PAREN;
}
continue;
case PARSER_ARG_STATE_EXPECT_CLOSE_PAREN:
if (implicit_factor_brace)
{
p--;
state = PARSER_ARG_STATE_EXPECT_END;
continue;
}
if (*p != ')')
{
error_string = "Expected closing parenthesis after blend factor";
goto error;
}
state = PARSER_ARG_STATE_EXPECT_END;
continue;
case PARSER_ARG_STATE_MAYBE_MULT:
if (*p == '*')
{
state = PARSER_ARG_STATE_EXPECT_OPEN_PAREN;
continue;
}
arg->factor.is_one = TRUE;
state = PARSER_ARG_STATE_EXPECT_END;
/* fall through */
case PARSER_ARG_STATE_EXPECT_END:
if (*p != ',' && *p != ')')
{
error_string = "expected , or )";
goto error;
}
*ret_p = p - 1;
return TRUE;
}
}
while (p++);
error:
{
int offset = p - string;
_cogl_set_error (error,
COGL_BLEND_STRING_ERROR,
COGL_BLEND_STRING_ERROR_ARGUMENT_PARSE_ERROR,
"Syntax error for argument %d at offset %d: %s",
current_arg,
offset,
error_string);
if (COGL_DEBUG_ENABLED (COGL_DEBUG_BLEND_STRINGS))
{
g_debug ("Syntax error for argument %d at offset %d: %s",
current_arg, offset, error_string);
}
return FALSE;
}
}
int
_cogl_blend_string_compile (const char *string,
CoglBlendStringContext context,
CoglBlendStringStatement *statements,
CoglError **error)
{
const char *p = string;
const char *mark = NULL;
const char *error_string;
ParserState state = PARSER_STATE_EXPECT_DEST_CHANNELS;
CoglBlendStringStatement *statement = statements;
int current_statement = 0;
int current_arg = 0;
int remaining_argc = 0;
#if 0
COGL_DEBUG_SET_FLAG (COGL_DEBUG_BLEND_STRINGS);
#endif
if (COGL_DEBUG_ENABLED (COGL_DEBUG_BLEND_STRINGS))
{
COGL_NOTE (BLEND_STRINGS, "Compiling %s string:\n%s\n",
context == COGL_BLEND_STRING_CONTEXT_BLENDING ?
"blend" : "texture combine",
string);
}
do
{
if (g_ascii_isspace (*p))
continue;
if (*p == '\0')
{
switch (state)
{
case PARSER_STATE_EXPECT_DEST_CHANNELS:
if (current_statement != 0)
goto finished;
error_string = "Empty statement";
goto error;
case PARSER_STATE_SCRAPING_DEST_CHANNELS:
error_string = "Expected an '=' following the destination "
"channel mask";
goto error;
case PARSER_STATE_EXPECT_FUNCTION_NAME:
error_string = "Expected a function name";
goto error;
case PARSER_STATE_SCRAPING_FUNCTION_NAME:
error_string = "Expected parenthesis after the function name";
goto error;
case PARSER_STATE_EXPECT_ARG_START:
error_string = "Expected to find the start of an argument";
goto error;
case PARSER_STATE_EXPECT_STATEMENT_END:
error_string = "Expected closing parenthesis for statement";
goto error;
}
}
switch (state)
{
case PARSER_STATE_EXPECT_DEST_CHANNELS:
mark = p;
state = PARSER_STATE_SCRAPING_DEST_CHANNELS;
/* fall through */
case PARSER_STATE_SCRAPING_DEST_CHANNELS:
if (*p != '=')
continue;
if (strncmp (mark, "RGBA", 4) == 0)
statement->mask = COGL_BLEND_STRING_CHANNEL_MASK_RGBA;
else if (strncmp (mark, "RGB", 3) == 0)
statement->mask = COGL_BLEND_STRING_CHANNEL_MASK_RGB;
else if (strncmp (mark, "A", 1) == 0)
statement->mask = COGL_BLEND_STRING_CHANNEL_MASK_ALPHA;
else
{
error_string = "Unknown destination channel mask; "
"expected RGBA=, RGB= or A=";
goto error;
}
state = PARSER_STATE_EXPECT_FUNCTION_NAME;
continue;
case PARSER_STATE_EXPECT_FUNCTION_NAME:
mark = p;
state = PARSER_STATE_SCRAPING_FUNCTION_NAME;
/* fall through */
case PARSER_STATE_SCRAPING_FUNCTION_NAME:
if (*p != '(')
{
if (!is_alphanum_char (*p))
{
error_string = "non alpha numeric character in function"
"name";
goto error;
}
continue;
}
statement->function = get_function_info (mark, p, context);
if (!statement->function)
{
error_string = "Unknown function name";
goto error;
}
remaining_argc = statement->function->argc;
current_arg = 0;
state = PARSER_STATE_EXPECT_ARG_START;
/* fall through */
case PARSER_STATE_EXPECT_ARG_START:
if (*p != '(' && *p != ',')
continue;
if (remaining_argc)
{
p++; /* parse_argument expects to see the first char of the arg */
if (!parse_argument (string, &p, statement,
current_arg, &statement->args[current_arg],
context, error))
return 0;
current_arg++;
remaining_argc--;
}
if (!remaining_argc)
state = PARSER_STATE_EXPECT_STATEMENT_END;
continue;
case PARSER_STATE_EXPECT_STATEMENT_END:
if (*p != ')')
{
error_string = "Expected end of statement";
goto error;
}
state = PARSER_STATE_EXPECT_DEST_CHANNELS;
if (current_statement++ == 1)
goto finished;
statement = &statements[current_statement];
}
}
while (p++);
finished:
if (COGL_DEBUG_ENABLED (COGL_DEBUG_BLEND_STRINGS))
{
if (current_statement > 0)
print_statement (0, &statements[0]);
if (current_statement > 1)
print_statement (1, &statements[1]);
}
if (!validate_statements_for_context (statements,
current_statement,
context,
error))
return 0;
return current_statement;
error:
{
int offset = p - string;
_cogl_set_error (error,
COGL_BLEND_STRING_ERROR,
COGL_BLEND_STRING_ERROR_PARSE_ERROR,
"Syntax error at offset %d: %s",
offset,
error_string);
if (COGL_DEBUG_ENABLED (COGL_DEBUG_BLEND_STRINGS))
{
g_debug ("Syntax error at offset %d: %s",
offset, error_string);
}
return 0;
}
}
/*
* INTERNAL TESTING CODE ...
*/
struct _TestString
{
const char *string;
CoglBlendStringContext context;
};
/* FIXME: this should probably be moved to a unit test */
int
_cogl_blend_string_test (void);
int
_cogl_blend_string_test (void)
{
struct _TestString strings[] = {
{" A = MODULATE ( TEXTURE[RGB], PREVIOUS[A], PREVIOUS[A] ) ",
COGL_BLEND_STRING_CONTEXT_TEXTURE_COMBINE },
{" RGB = MODULATE ( TEXTURE[RGB], PREVIOUS[A] ) ",
COGL_BLEND_STRING_CONTEXT_TEXTURE_COMBINE },
{"A=ADD(TEXTURE[A],PREVIOUS[RGB])",
COGL_BLEND_STRING_CONTEXT_TEXTURE_COMBINE },
{"A=ADD(TEXTURE[A],PREVIOUS[RGB])",
COGL_BLEND_STRING_CONTEXT_TEXTURE_COMBINE },
{"RGBA = ADD(SRC_COLOR*(SRC_COLOR[A]), DST_COLOR*(1-SRC_COLOR[A]))",
COGL_BLEND_STRING_CONTEXT_BLENDING },
{"RGB = ADD(SRC_COLOR, DST_COLOR*(0))",
COGL_BLEND_STRING_CONTEXT_BLENDING },
{"RGB = ADD(SRC_COLOR, 0)",
COGL_BLEND_STRING_CONTEXT_BLENDING },
{"RGB = ADD()",
COGL_BLEND_STRING_CONTEXT_BLENDING },
{"RGB = ADD(SRC_COLOR, 0, DST_COLOR)",
COGL_BLEND_STRING_CONTEXT_BLENDING },
{NULL}
};
int i;
CoglError *error = NULL;
for (i = 0; strings[i].string; i++)
{
CoglBlendStringStatement statements[2];
int count = _cogl_blend_string_compile (strings[i].string,
strings[i].context,
statements,
&error);
if (!count)
{
g_print ("Failed to parse string:\n%s\n%s\n",
strings[i].string,
error->message);
cogl_error_free (error);
error = NULL;
continue;
}
g_print ("Original:\n");
g_print ("%s\n", strings[i].string);
if (count > 0)
print_statement (0, &statements[0]);
if (count > 1)
print_statement (1, &statements[1]);
}
return 0;
}
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