mutter/cogl/driver/gl/cogl-pipeline-vertend-glsl.c
Neil Roberts 956d39ac30 Add fragment and vertex snippet hooks for global declarations
This adds hook points to add global function and variable declarations
to either the fragment or vertex shader. The declarations can then be
used by subsequent snippets. Only the ‘declarations’ string of the
snippet is used and the code is directly put in the global scope near
the top of the shader.

The reason this is necessary rather than just adding a normal snippet
with the declarations is that for the other hooks Cogl assumes that
the snippets are independent of each other. That means if a snippet
has a replace string then it will assume that it doesn't even need to
generate the code for earlier hooks which means the global
declarations would be lost.

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

(cherry picked from commit ebb82d5b0bc30487b7101dc66b769160b40f92ca)
2013-02-27 14:43:55 +00:00

521 lines
17 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2010,2013 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:
* Neil Roberts <neil@linux.intel.com>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "cogl-context-private.h"
#include "cogl-util-gl-private.h"
#include "cogl-pipeline-private.h"
#include "cogl-pipeline-opengl-private.h"
#ifdef COGL_PIPELINE_VERTEND_GLSL
#include "cogl-context-private.h"
#include "cogl-object-private.h"
#include "cogl-program-private.h"
#include "cogl-pipeline-vertend-glsl-private.h"
#include "cogl-pipeline-state-private.h"
#include "cogl-glsl-shader-private.h"
const CoglPipelineVertend _cogl_pipeline_glsl_vertend;
typedef struct
{
unsigned int ref_count;
GLuint gl_shader;
GString *header, *source;
} CoglPipelineShaderState;
static CoglUserDataKey shader_state_key;
static CoglPipelineShaderState *
shader_state_new (void)
{
CoglPipelineShaderState *shader_state;
shader_state = g_slice_new0 (CoglPipelineShaderState);
shader_state->ref_count = 1;
return shader_state;
}
static CoglPipelineShaderState *
get_shader_state (CoglPipeline *pipeline)
{
return cogl_object_get_user_data (COGL_OBJECT (pipeline), &shader_state_key);
}
static void
destroy_shader_state (void *user_data)
{
CoglPipelineShaderState *shader_state = user_data;
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
if (--shader_state->ref_count == 0)
{
if (shader_state->gl_shader)
GE( ctx, glDeleteShader (shader_state->gl_shader) );
g_slice_free (CoglPipelineShaderState, shader_state);
}
}
static void
set_shader_state (CoglPipeline *pipeline,
CoglPipelineShaderState *shader_state)
{
cogl_object_set_user_data (COGL_OBJECT (pipeline),
&shader_state_key,
shader_state,
destroy_shader_state);
}
static void
dirty_shader_state (CoglPipeline *pipeline)
{
cogl_object_set_user_data (COGL_OBJECT (pipeline),
&shader_state_key,
NULL,
NULL);
}
GLuint
_cogl_pipeline_vertend_glsl_get_shader (CoglPipeline *pipeline)
{
CoglPipelineShaderState *shader_state = get_shader_state (pipeline);
if (shader_state)
return shader_state->gl_shader;
else
return 0;
}
static CoglPipelineSnippetList *
get_vertex_snippets (CoglPipeline *pipeline)
{
pipeline =
_cogl_pipeline_get_authority (pipeline,
COGL_PIPELINE_STATE_VERTEX_SNIPPETS);
return &pipeline->big_state->vertex_snippets;
}
static CoglPipelineSnippetList *
get_layer_vertex_snippets (CoglPipelineLayer *layer)
{
unsigned long state = COGL_PIPELINE_LAYER_STATE_VERTEX_SNIPPETS;
layer = _cogl_pipeline_layer_get_authority (layer, state);
return &layer->big_state->vertex_snippets;
}
static void
add_global_declarations (CoglPipeline *pipeline,
CoglPipelineShaderState *shader_state)
{
CoglSnippetHook hook = COGL_SNIPPET_HOOK_VERTEX_GLOBALS;
CoglPipelineSnippetList *snippets = get_vertex_snippets (pipeline);
/* Add the global data hooks. All of the code in these snippets is
* always added and only the declarations data is used */
_cogl_pipeline_snippet_generate_declarations (shader_state->header,
hook,
snippets);
}
static void
_cogl_pipeline_vertend_glsl_start (CoglPipeline *pipeline,
int n_layers,
unsigned long pipelines_difference)
{
CoglPipelineShaderState *shader_state;
CoglPipeline *template_pipeline = NULL;
CoglProgram *user_program = cogl_pipeline_get_user_program (pipeline);
_COGL_GET_CONTEXT (ctx, NO_RETVAL);
/* Now lookup our glsl backend private state (allocating if
* necessary) */
shader_state = get_shader_state (pipeline);
if (shader_state == NULL)
{
CoglPipeline *authority;
/* Get the authority for anything affecting vertex shader
state */
authority = _cogl_pipeline_find_equivalent_parent
(pipeline,
COGL_PIPELINE_STATE_AFFECTS_VERTEX_CODEGEN &
~COGL_PIPELINE_STATE_LAYERS,
COGL_PIPELINE_LAYER_STATE_AFFECTS_VERTEX_CODEGEN);
shader_state = get_shader_state (authority);
if (shader_state == NULL)
{
/* Check if there is already a similar cached pipeline whose
shader state we can share */
if (G_LIKELY (!(COGL_DEBUG_ENABLED
(COGL_DEBUG_DISABLE_PROGRAM_CACHES))))
{
template_pipeline =
_cogl_pipeline_cache_get_vertex_template (ctx->pipeline_cache,
authority);
shader_state = get_shader_state (template_pipeline);
}
if (shader_state)
shader_state->ref_count++;
else
shader_state = shader_state_new ();
set_shader_state (authority, shader_state);
if (template_pipeline)
{
shader_state->ref_count++;
set_shader_state (template_pipeline, shader_state);
}
}
if (authority != pipeline)
{
shader_state->ref_count++;
set_shader_state (pipeline, shader_state);
}
}
if (user_program)
{
/* If the user program contains a vertex shader then we don't need
to generate one */
if (_cogl_program_has_vertex_shader (user_program))
{
if (shader_state->gl_shader)
{
GE( ctx, glDeleteShader (shader_state->gl_shader) );
shader_state->gl_shader = 0;
}
return;
}
}
if (shader_state->gl_shader)
return;
/* If we make it here then we have a shader_state struct without a gl_shader
either because this is the first time we've encountered it or
because the user program has changed */
/* We reuse two grow-only GStrings for code-gen. One string
contains the uniform and attribute declarations while the
other contains the main function. We need two strings
because we need to dynamically declare attributes as the
add_layer callback is invoked */
g_string_set_size (ctx->codegen_header_buffer, 0);
g_string_set_size (ctx->codegen_source_buffer, 0);
shader_state->header = ctx->codegen_header_buffer;
shader_state->source = ctx->codegen_source_buffer;
add_global_declarations (pipeline, shader_state);
g_string_append (shader_state->source,
"void\n"
"cogl_generated_source ()\n"
"{\n");
if (!(ctx->private_feature_flags &
COGL_PRIVATE_FEATURE_BUILTIN_POINT_SIZE_UNIFORM))
/* There is no builtin uniform for the pointsize on GLES2 so we need
to copy it from the custom uniform in the vertex shader */
g_string_append (shader_state->source,
" cogl_point_size_out = cogl_point_size_in;\n");
}
static CoglBool
_cogl_pipeline_vertend_glsl_add_layer (CoglPipeline *pipeline,
CoglPipelineLayer *layer,
unsigned long layers_difference,
CoglFramebuffer *framebuffer)
{
CoglPipelineShaderState *shader_state;
CoglPipelineSnippetData snippet_data;
int layer_index = layer->index;
_COGL_GET_CONTEXT (ctx, FALSE);
shader_state = get_shader_state (pipeline);
if (shader_state->source == NULL)
return TRUE;
/* Transform the texture coordinates by the layer's user matrix.
*
* FIXME: this should avoid doing the transform if there is no user
* matrix set. This might need a separate layer state flag for
* whether there is a user matrix
*
* FIXME: we could be more clever here and try to detect if the
* fragment program is going to use the texture coordinates and
* avoid setting them if not
*/
g_string_append_printf (shader_state->header,
"vec4\n"
"cogl_real_transform_layer%i (mat4 matrix, "
"vec4 tex_coord)\n"
"{\n"
" return matrix * tex_coord;\n"
"}\n",
layer_index);
/* Wrap the layer code in any snippets that have been hooked */
memset (&snippet_data, 0, sizeof (snippet_data));
snippet_data.snippets = get_layer_vertex_snippets (layer);
snippet_data.hook = COGL_SNIPPET_HOOK_TEXTURE_COORD_TRANSFORM;
snippet_data.chain_function = g_strdup_printf ("cogl_real_transform_layer%i",
layer_index);
snippet_data.final_name = g_strdup_printf ("cogl_transform_layer%i",
layer_index);
snippet_data.function_prefix = g_strdup_printf ("cogl_transform_layer%i",
layer_index);
snippet_data.return_type = "vec4";
snippet_data.return_variable = "cogl_tex_coord";
snippet_data.return_variable_is_argument = TRUE;
snippet_data.arguments = "cogl_matrix, cogl_tex_coord";
snippet_data.argument_declarations = "mat4 cogl_matrix, vec4 cogl_tex_coord";
snippet_data.source_buf = shader_state->header;
_cogl_pipeline_snippet_generate_code (&snippet_data);
g_free ((char *) snippet_data.chain_function);
g_free ((char *) snippet_data.final_name);
g_free ((char *) snippet_data.function_prefix);
g_string_append_printf (shader_state->source,
" cogl_tex_coord%i_out = "
"cogl_transform_layer%i (cogl_texture_matrix%i,\n"
" "
" cogl_tex_coord%i_in);\n",
layer_index,
layer_index,
layer_index,
layer_index);
return TRUE;
}
static CoglBool
_cogl_pipeline_vertend_glsl_end (CoglPipeline *pipeline,
unsigned long pipelines_difference)
{
CoglPipelineShaderState *shader_state;
_COGL_GET_CONTEXT (ctx, FALSE);
shader_state = get_shader_state (pipeline);
if (shader_state->source)
{
const char *source_strings[2];
GLint lengths[2];
GLint compile_status;
GLuint shader;
CoglPipelineSnippetData snippet_data;
CoglPipelineSnippetList *vertex_snippets;
COGL_STATIC_COUNTER (vertend_glsl_compile_counter,
"glsl vertex compile counter",
"Increments each time a new GLSL "
"vertex shader is compiled",
0 /* no application private data */);
COGL_COUNTER_INC (_cogl_uprof_context, vertend_glsl_compile_counter);
g_string_append (shader_state->header,
"void\n"
"cogl_real_vertex_transform ()\n"
"{\n"
" cogl_position_out = "
"cogl_modelview_projection_matrix * "
"cogl_position_in;\n"
"}\n");
g_string_append (shader_state->source,
" cogl_vertex_transform ();\n"
" cogl_color_out = cogl_color_in;\n"
"}\n");
vertex_snippets = get_vertex_snippets (pipeline);
/* Add hooks for the vertex transform part */
memset (&snippet_data, 0, sizeof (snippet_data));
snippet_data.snippets = vertex_snippets;
snippet_data.hook = COGL_SNIPPET_HOOK_VERTEX_TRANSFORM;
snippet_data.chain_function = "cogl_real_vertex_transform";
snippet_data.final_name = "cogl_vertex_transform";
snippet_data.function_prefix = "cogl_vertex_transform";
snippet_data.source_buf = shader_state->header;
_cogl_pipeline_snippet_generate_code (&snippet_data);
/* Add all of the hooks for vertex processing */
memset (&snippet_data, 0, sizeof (snippet_data));
snippet_data.snippets = vertex_snippets;
snippet_data.hook = COGL_SNIPPET_HOOK_VERTEX;
snippet_data.chain_function = "cogl_generated_source";
snippet_data.final_name = "cogl_vertex_hook";
snippet_data.function_prefix = "cogl_vertex_hook";
snippet_data.source_buf = shader_state->source;
_cogl_pipeline_snippet_generate_code (&snippet_data);
g_string_append (shader_state->source,
"void\n"
"main ()\n"
"{\n"
" cogl_vertex_hook ();\n");
/* If there are any snippets then we can't rely on the
projection matrix to flip the rendering for offscreen buffers
so we'll need to flip it using an extra statement and a
uniform */
if (_cogl_pipeline_has_vertex_snippets (pipeline))
{
g_string_append (shader_state->header,
"uniform vec4 _cogl_flip_vector;\n");
g_string_append (shader_state->source,
" cogl_position_out *= _cogl_flip_vector;\n");
}
g_string_append (shader_state->source,
"}\n");
GE_RET( shader, ctx, glCreateShader (GL_VERTEX_SHADER) );
lengths[0] = shader_state->header->len;
source_strings[0] = shader_state->header->str;
lengths[1] = shader_state->source->len;
source_strings[1] = shader_state->source->str;
_cogl_glsl_shader_set_source_with_boilerplate (ctx,
NULL,
shader, GL_VERTEX_SHADER,
pipeline,
2, /* count */
source_strings, lengths);
GE( ctx, glCompileShader (shader) );
GE( ctx, glGetShaderiv (shader, GL_COMPILE_STATUS, &compile_status) );
if (!compile_status)
{
GLint len = 0;
char *shader_log;
GE( ctx, glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &len) );
shader_log = g_alloca (len);
GE( ctx, glGetShaderInfoLog (shader, len, &len, shader_log) );
g_warning ("Shader compilation failed:\n%s", shader_log);
}
shader_state->header = NULL;
shader_state->source = NULL;
shader_state->gl_shader = shader;
}
if ((ctx->private_feature_flags &
COGL_PRIVATE_FEATURE_BUILTIN_POINT_SIZE_UNIFORM) &&
(pipelines_difference & COGL_PIPELINE_STATE_POINT_SIZE))
{
CoglPipeline *authority =
_cogl_pipeline_get_authority (pipeline, COGL_PIPELINE_STATE_POINT_SIZE);
GE( ctx, glPointSize (authority->big_state->point_size) );
}
return TRUE;
}
static void
_cogl_pipeline_vertend_glsl_pre_change_notify (CoglPipeline *pipeline,
CoglPipelineState change,
const CoglColor *new_color)
{
if ((change & COGL_PIPELINE_STATE_AFFECTS_VERTEX_CODEGEN))
dirty_shader_state (pipeline);
}
/* NB: layers are considered immutable once they have any dependants
* so although multiple pipelines can end up depending on a single
* static layer, we can guarantee that if a layer is being *changed*
* then it can only have one pipeline depending on it.
*
* XXX: Don't forget this is *pre* change, we can't read the new value
* yet!
*/
static void
_cogl_pipeline_vertend_glsl_layer_pre_change_notify (
CoglPipeline *owner,
CoglPipelineLayer *layer,
CoglPipelineLayerState change)
{
CoglPipelineShaderState *shader_state;
shader_state = get_shader_state (owner);
if (!shader_state)
return;
if ((change & COGL_PIPELINE_LAYER_STATE_AFFECTS_VERTEX_CODEGEN))
{
dirty_shader_state (owner);
return;
}
/* TODO: we could be saving snippets of texture combine code along
* with each layer and then when a layer changes we would just free
* the snippet. */
}
const CoglPipelineVertend _cogl_pipeline_glsl_vertend =
{
_cogl_pipeline_vertend_glsl_start,
_cogl_pipeline_vertend_glsl_add_layer,
_cogl_pipeline_vertend_glsl_end,
_cogl_pipeline_vertend_glsl_pre_change_notify,
_cogl_pipeline_vertend_glsl_layer_pre_change_notify
};
#endif /* COGL_PIPELINE_VERTEND_GLSL */