mutter/cogl/cogl-pipeline-fragend-fixed.c
Neil Roberts e6b3bfa41a pipeline: Use layer numbers not unit numbers in the combine strings
In a combine string the application can specify TEXTURE_? as a source
to sample from the texture attached to a particular unit. The number
specified here was being interpreted as a unit index. This is not
helpful to applications because theoretically the unit index is an
internal implementation detail so they can't reliably determine what
it is. This patch changes them to be interpreted as layer indices
instead.

To make this work the enums in CoglPipelineCombineSource are no longer
directly mapped to GLenums. Otherwise it implies a low limit on the
number of layer indices because there are only 32 reserved numbers
between GL_TEXTURE0 and GL_ACTIVE_TEXTURE.

This also fixes a bug in the ARBfp fragend where it was generating
code using the texture type of the layer doing the referencing rather
than the layer that was being referenced.

Reviewed-by: Robert Bragg <robert@linux.intel.com>
2012-02-13 17:15:35 +00:00

453 lines
14 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2008,2009,2010 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 "cogl-context-private.h"
#include "cogl-pipeline-private.h"
#include "cogl-pipeline-state-private.h"
#include "cogl-pipeline-opengl-private.h"
#ifdef COGL_PIPELINE_FRAGEND_FIXED
#include "cogl.h"
#include "cogl-internal.h"
#include "cogl-context-private.h"
#include "cogl-handle.h"
#include "cogl-texture-private.h"
#include "cogl-blend-string.h"
#include "cogl-profile.h"
#include "cogl-program-private.h"
#include <glib.h>
#include <glib/gprintf.h>
#include <string.h>
#ifndef GL_TEXTURE_RECTANGLE_ARB
#define GL_TEXTURE_RECTANGLE_ARB 0x84F5
#endif
const CoglPipelineFragend _cogl_pipeline_fixed_fragend;
static void
_cogl_disable_texture_unit (int unit_index)
{
CoglTextureUnit *unit;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
unit = &g_array_index (ctx->texture_units, CoglTextureUnit, unit_index);
if (unit->enabled_gl_target)
{
_cogl_set_active_texture_unit (unit_index);
GE (ctx, glDisable (unit->enabled_gl_target));
unit->enabled_gl_target = 0;
}
}
static int
get_max_texture_units (void)
{
_COGL_GET_CONTEXT (ctx, 0);
/* This function is called quite often so we cache the value to
avoid too many GL calls */
if (ctx->max_texture_units == -1)
{
ctx->max_texture_units = 1;
GE (ctx, glGetIntegerv (GL_MAX_TEXTURE_UNITS,
&ctx->max_texture_units));
}
return ctx->max_texture_units;
}
static gboolean
_cogl_pipeline_fragend_fixed_start (CoglPipeline *pipeline,
int n_layers,
unsigned long pipelines_difference,
int n_tex_coord_attribs)
{
CoglHandle user_program;
_COGL_GET_CONTEXT (ctx, FALSE);
if (G_UNLIKELY (COGL_DEBUG_ENABLED (COGL_DEBUG_DISABLE_FIXED)))
return FALSE;
if (ctx->driver == COGL_DRIVER_GLES2)
return FALSE;
/* Fragment snippets are only supported in the GLSL fragend */
if (_cogl_pipeline_has_fragment_snippets (pipeline))
return FALSE;
/* If there is a user program with a fragment shader then the
appropriate backend for that language should handle it. We can
still use the fixed fragment backend if the program only contains
a vertex shader */
user_program = cogl_pipeline_get_user_program (pipeline);
if (user_program != COGL_INVALID_HANDLE &&
_cogl_program_has_fragment_shader (user_program))
return FALSE;
_cogl_use_fragment_program (0, COGL_PIPELINE_PROGRAM_TYPE_FIXED);
return TRUE;
}
static void
translate_sources (CoglPipeline *pipeline,
int n_sources,
CoglPipelineCombineSource *source_in,
GLenum *source_out)
{
int i;
/* The texture source numbers specified in the layer combine are the
layer numbers so we need to map these to unit indices */
for (i = 0; i < n_sources; i++)
switch (source_in[i])
{
case COGL_PIPELINE_COMBINE_SOURCE_TEXTURE:
source_out[i] = GL_TEXTURE;
break;
case COGL_PIPELINE_COMBINE_SOURCE_CONSTANT:
source_out[i] = GL_CONSTANT;
break;
case COGL_PIPELINE_COMBINE_SOURCE_PRIMARY_COLOR:
source_out[i] = GL_PRIMARY_COLOR;
break;
case COGL_PIPELINE_COMBINE_SOURCE_PREVIOUS:
source_out[i] = GL_PREVIOUS;
break;
default:
{
int layer_num = source_in[i] - COGL_PIPELINE_COMBINE_SOURCE_TEXTURE0;
CoglPipelineGetLayerFlags flags = COGL_PIPELINE_GET_LAYER_NO_CREATE;
CoglPipelineLayer *layer =
_cogl_pipeline_get_layer_with_flags (pipeline, layer_num, flags);
if (layer == NULL)
{
static gboolean warning_seen = FALSE;
if (!warning_seen)
{
g_warning ("The application is trying to use a texture "
"combine with a layer number that does not exist");
warning_seen = TRUE;
}
source_out[i] = GL_PREVIOUS;
}
else
source_out[i] = (_cogl_pipeline_layer_get_unit_index (layer) +
GL_TEXTURE0);
}
}
}
static gboolean
_cogl_pipeline_fragend_fixed_add_layer (CoglPipeline *pipeline,
CoglPipelineLayer *layer,
unsigned long layers_difference)
{
CoglTextureUnit *unit =
_cogl_get_texture_unit (_cogl_pipeline_layer_get_unit_index (layer));
int unit_index = unit->index;
int n_rgb_func_args;
int n_alpha_func_args;
_COGL_GET_CONTEXT (ctx, FALSE);
/* XXX: Beware that since we are changing the active texture unit we
* must make sure we don't call into other Cogl components that may
* temporarily bind texture objects to query/modify parameters since
* they will end up binding texture unit 1. See
* _cogl_bind_gl_texture_transient for more details.
*/
_cogl_set_active_texture_unit (unit_index);
if (G_UNLIKELY (unit_index >= get_max_texture_units ()))
{
_cogl_disable_texture_unit (unit_index);
/* TODO: although this isn't considered an error that
* warrants falling back to a different backend we
* should print a warning here. */
return TRUE;
}
/* Handle enabling or disabling the right texture type */
if (layers_difference & COGL_PIPELINE_LAYER_STATE_TEXTURE_TYPE)
{
CoglTextureType texture_type =
_cogl_pipeline_layer_get_texture_type (layer);
GLenum gl_target;
switch (texture_type)
{
case COGL_TEXTURE_TYPE_2D:
gl_target = GL_TEXTURE_2D;
break;
case COGL_TEXTURE_TYPE_3D:
gl_target = GL_TEXTURE_3D;
break;
case COGL_TEXTURE_TYPE_RECTANGLE:
gl_target = GL_TEXTURE_RECTANGLE_ARB;
break;
}
_cogl_set_active_texture_unit (unit_index);
/* The common GL code handles binding the right texture so we
just need to handle enabling and disabling it */
if (unit->enabled_gl_target != gl_target)
{
/* Disable the previous target if it's still enabled */
if (unit->enabled_gl_target)
GE (ctx, glDisable (unit->enabled_gl_target));
/* Enable the new target */
if (!G_UNLIKELY (COGL_DEBUG_ENABLED (COGL_DEBUG_DISABLE_TEXTURING)))
{
GE (ctx, glEnable (gl_target));
unit->enabled_gl_target = gl_target;
}
}
}
else
{
/* Even though there may be no difference between the last flushed
* texture state and the current layers texture state it may be that the
* texture unit has been disabled for some time so we need to assert that
* it's enabled now.
*/
if (!G_UNLIKELY (COGL_DEBUG_ENABLED (COGL_DEBUG_DISABLE_TEXTURING)) &&
unit->enabled_gl_target == 0)
{
_cogl_set_active_texture_unit (unit_index);
GE (ctx, glEnable (unit->gl_target));
unit->enabled_gl_target = unit->gl_target;
}
}
if (layers_difference & COGL_PIPELINE_LAYER_STATE_COMBINE)
{
CoglPipelineLayer *authority =
_cogl_pipeline_layer_get_authority (layer,
COGL_PIPELINE_LAYER_STATE_COMBINE);
CoglPipelineLayerBigState *big_state = authority->big_state;
GLenum sources[3];
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE));
/* Set the combiner functions... */
GE (ctx, glTexEnvi (GL_TEXTURE_ENV,
GL_COMBINE_RGB,
big_state->texture_combine_rgb_func));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV,
GL_COMBINE_ALPHA,
big_state->texture_combine_alpha_func));
/*
* Setup the function arguments...
*/
/* For the RGB components... */
n_rgb_func_args =
_cogl_get_n_args_for_combine_func (big_state->texture_combine_rgb_func);
translate_sources (pipeline,
n_rgb_func_args,
big_state->texture_combine_rgb_src,
sources);
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_RGB,
sources[0]));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_RGB,
big_state->texture_combine_rgb_op[0]));
if (n_rgb_func_args > 1)
{
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_SRC1_RGB,
sources[1]));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND1_RGB,
big_state->texture_combine_rgb_op[1]));
}
if (n_rgb_func_args > 2)
{
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_SRC2_RGB,
sources[2]));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND2_RGB,
big_state->texture_combine_rgb_op[2]));
}
/* For the Alpha component */
n_alpha_func_args =
_cogl_get_n_args_for_combine_func (big_state->texture_combine_alpha_func);
translate_sources (pipeline,
n_alpha_func_args,
big_state->texture_combine_alpha_src,
sources);
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_SRC0_ALPHA,
sources[0]));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_ALPHA,
big_state->texture_combine_alpha_op[0]));
if (n_alpha_func_args > 1)
{
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_SRC1_ALPHA,
sources[1]));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND1_ALPHA,
big_state->texture_combine_alpha_op[1]));
}
if (n_alpha_func_args > 2)
{
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_SRC2_ALPHA,
sources[2]));
GE (ctx, glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND2_ALPHA,
big_state->texture_combine_alpha_op[2]));
}
}
if (layers_difference & COGL_PIPELINE_LAYER_STATE_COMBINE_CONSTANT)
{
CoglPipelineLayer *authority =
_cogl_pipeline_layer_get_authority
(layer, COGL_PIPELINE_LAYER_STATE_COMBINE_CONSTANT);
CoglPipelineLayerBigState *big_state = authority->big_state;
GE (ctx, glTexEnvfv (GL_TEXTURE_ENV, GL_TEXTURE_ENV_COLOR,
big_state->texture_combine_constant));
}
return TRUE;
}
static gboolean
get_highest_unit_index_cb (CoglPipelineLayer *layer,
void *user_data)
{
int unit_index = _cogl_pipeline_layer_get_unit_index (layer);
int *highest_index = user_data;
*highest_index = unit_index;
return TRUE;
}
static gboolean
_cogl_pipeline_fragend_fixed_end (CoglPipeline *pipeline,
unsigned long pipelines_difference)
{
int highest_unit_index = -1;
int i;
_COGL_GET_CONTEXT (ctx, FALSE);
_cogl_pipeline_foreach_layer_internal (pipeline,
get_highest_unit_index_cb,
&highest_unit_index);
/* Disable additional texture units that may have previously been in use.. */
for (i = highest_unit_index + 1; i < ctx->texture_units->len; i++)
_cogl_disable_texture_unit (i);
if (pipelines_difference & COGL_PIPELINE_STATE_FOG)
{
CoglPipeline *authority =
_cogl_pipeline_get_authority (pipeline, COGL_PIPELINE_STATE_FOG);
CoglPipelineFogState *fog_state = &authority->big_state->fog_state;
if (fog_state->enabled)
{
GLfloat fogColor[4];
GLenum gl_mode = GL_LINEAR;
fogColor[0] = cogl_color_get_red_float (&fog_state->color);
fogColor[1] = cogl_color_get_green_float (&fog_state->color);
fogColor[2] = cogl_color_get_blue_float (&fog_state->color);
fogColor[3] = cogl_color_get_alpha_float (&fog_state->color);
GE (ctx, glEnable (GL_FOG));
GE (ctx, glFogfv (GL_FOG_COLOR, fogColor));
if (ctx->driver == COGL_DRIVER_GLES1)
switch (fog_state->mode)
{
case COGL_FOG_MODE_LINEAR:
gl_mode = GL_LINEAR;
break;
case COGL_FOG_MODE_EXPONENTIAL:
gl_mode = GL_EXP;
break;
case COGL_FOG_MODE_EXPONENTIAL_SQUARED:
gl_mode = GL_EXP2;
break;
}
/* TODO: support other modes for GLES2 */
/* NB: GLES doesn't have glFogi */
GE (ctx, glFogf (GL_FOG_MODE, gl_mode));
GE (ctx, glHint (GL_FOG_HINT, GL_NICEST));
GE (ctx, glFogf (GL_FOG_DENSITY, fog_state->density));
GE (ctx, glFogf (GL_FOG_START, fog_state->z_near));
GE (ctx, glFogf (GL_FOG_END, fog_state->z_far));
}
else
GE (ctx, glDisable (GL_FOG));
}
return TRUE;
}
const CoglPipelineFragend _cogl_pipeline_fixed_fragend =
{
_cogl_pipeline_fragend_fixed_start,
_cogl_pipeline_fragend_fixed_add_layer,
NULL, /* passthrough */
_cogl_pipeline_fragend_fixed_end,
NULL, /* pipeline_change_notify */
NULL, /* pipeline_set_parent_notify */
NULL, /* layer_change_notify */
};
#endif /* COGL_PIPELINE_FRAGEND_FIXED */