cogl-pipeline: Add support for setting uniform values

This adds the following new public experimental functions to set
uniform values on a CoglPipeline:

void
cogl_pipeline_set_uniform_1f (CoglPipeline *pipeline,
                              int uniform_location,
                              float value);
void
cogl_pipeline_set_uniform_1i (CoglPipeline *pipeline,
                              int uniform_location,
                              int value);
void
cogl_pipeline_set_uniform_float (CoglPipeline *pipeline,
                                 int uniform_location,
                                 int n_components,
                                 int count,
                                 const float *value);
void
cogl_pipeline_set_uniform_int (CoglPipeline *pipeline,
                               int uniform_location,
                               int n_components,
                               int count,
                               const int *value);
void
cogl_pipeline_set_uniform_matrix (CoglPipeline *pipeline,
                                  int uniform_location,
                                  int dimensions,
                                  int count,
                                  gboolean transpose,
                                  const float *value);

These are similar to the old functions used to set uniforms on a
CoglProgram. To get a value to pass in as the uniform_location there
is also:

int
cogl_pipeline_get_uniform_location (CoglPipeline *pipeline,
                                    const char *uniform_name);

Conceptually the uniform locations are tied to the pipeline so that
whenever setting a value for a new pipeline the application is
expected to call this function. However in practice the uniform
locations are global to the CoglContext. The names are stored in a
linked list where the position in the list is the uniform location.

The global indices are used so that each pipeline can store a mask of
which uniforms it overrides. That way it is quicker to detect which
uniforms are different from the last pipeline that used the same
CoglProgramState so it can avoid flushing uniforms that haven't
changed. Currently the values are not actually compared which means
that it will only avoid flushing a uniform if there is a common
ancestor that sets the value (or if the same pipeline is being flushed
again - in which case the pipeline and its common ancestor are the
same thing).

The uniform values are stored in the big state of the pipeline as a
sparse linked list. A bitmask stores which values have been overridden
and only overridden values are stored in the linked list.

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

1 files changed, 160 insertions, 0 deletions

diff --git a/cogl/cogl-pipeline-state.h b/cogl/cogl-pipeline-state.h
index 5dfd21a1..cd6a22b7 100644
--- a/cogl/cogl-pipeline-state.h
+++ b/cogl/cogl-pipeline-state.h
@@ -777,6 +777,166 @@ cogl_pipeline_set_front_face_winding (CoglPipeline *pipeline,
 CoglWinding
 cogl_pipeline_get_front_face_winding (CoglPipeline *pipeline);
 
+#define cogl_pipeline_set_uniform_1f \
+        cogl_pipeline_set_uniform_1f_EXP
+/**
+ * cogl_pipeline_set_uniform_1f:
+ * @pipeline: A #CoglPipeline object
+ * @uniform_location: The uniform's location identifier
+ * @value: The new value for the uniform
+ *
+ * Sets a new value for the uniform at @uniform_location. If this
+ * pipeline has a user program attached and is later used as a source
+ * for drawing, the given value will be assigned to the uniform which
+ * can be accessed from the shader's source. The value for
+ * @uniform_location should be retrieved from the string name of the
+ * uniform by calling cogl_pipeline_get_uniform_location().
+ *
+ * This function should be used to set uniforms that are of type
+ * float. It can also be used to set a single member of a float array
+ * uniform.
+ *
+ * Since: 2.0
+ * Stability: Unstable
+ */
+void
+cogl_pipeline_set_uniform_1f (CoglPipeline *pipeline,
+                              int uniform_location,
+                              float value);
+
+#define cogl_pipeline_set_uniform_1i \
+        cogl_pipeline_set_uniform_1i_EXP
+/**
+ * cogl_pipeline_set_uniform_1i:
+ * @pipeline: A #CoglPipeline object
+ * @uniform_location: The uniform's location identifier
+ * @value: The new value for the uniform
+ *
+ * Sets a new value for the uniform at @uniform_location. If this
+ * pipeline has a user program attached and is later used as a source
+ * for drawing, the given value will be assigned to the uniform which
+ * can be accessed from the shader's source. The value for
+ * @uniform_location should be retrieved from the string name of the
+ * uniform by calling cogl_pipeline_get_uniform_location().
+ *
+ * This function should be used to set uniforms that are of type
+ * int. It can also be used to set a single member of a int array
+ * uniform or a sampler uniform.
+ *
+ * Since: 2.0
+ * Stability: Unstable
+ */
+void
+cogl_pipeline_set_uniform_1i (CoglPipeline *pipeline,
+                              int uniform_location,
+                              int value);
+
+#define cogl_pipeline_set_uniform_float \
+        cogl_pipeline_set_uniform_float_EXP
+/**
+ * cogl_pipeline_set_uniform_float:
+ * @pipeline: A #CoglPipeline object
+ * @uniform_location: The uniform's location identifier
+ * @n_components: The number of components in the corresponding uniform's type
+ * @count: The number of values to set
+ * @value: Pointer to the new values to set
+ *
+ * Sets new values for the uniform at @uniform_location. If this
+ * pipeline has a user program attached and is later used as a source
+ * for drawing, the given values will be assigned to the uniform which
+ * can be accessed from the shader's source. The value for
+ * @uniform_location should be retrieved from the string name of the
+ * uniform by calling cogl_pipeline_get_uniform_location().
+ *
+ * This function can be used to set any floating point type uniform,
+ * including float arrays and float vectors. For example, to set a
+ * single vec4 uniform you would use 4 for @n_components and 1 for
+ * @count. To set an array of 8 float values, you could use 1 for
+ * @n_components and 8 for @count.
+ *
+ * Since: 2.0
+ * Stability: Unstable
+ */
+void
+cogl_pipeline_set_uniform_float (CoglPipeline *pipeline,
+                                 int uniform_location,
+                                 int n_components,
+                                 int count,
+                                 const float *value);
+
+#define cogl_pipeline_set_uniform_int \
+        cogl_pipeline_set_uniform_int_EXP
+/**
+ * cogl_pipeline_set_uniform_int:
+ * @pipeline: A #CoglPipeline object
+ * @uniform_location: The uniform's location identifier
+ * @n_components: The number of components in the corresponding uniform's type
+ * @count: The number of values to set
+ * @value: Pointer to the new values to set
+ *
+ * Sets new values for the uniform at @uniform_location. If this
+ * pipeline has a user program attached and is later used as a source
+ * for drawing, the given values will be assigned to the uniform which
+ * can be accessed from the shader's source. The value for
+ * @uniform_location should be retrieved from the string name of the
+ * uniform by calling cogl_pipeline_get_uniform_location().
+ *
+ * This function can be used to set any integer type uniform,
+ * including int arrays and int vectors. For example, to set a single
+ * ivec4 uniform you would use 4 for @n_components and 1 for
+ * @count. To set an array of 8 int values, you could use 1 for
+ * @n_components and 8 for @count.
+ *
+ * Since: 2.0
+ * Stability: Unstable
+ */
+void
+cogl_pipeline_set_uniform_int (CoglPipeline *pipeline,
+                               int uniform_location,
+                               int n_components,
+                               int count,
+                               const int *value);
+
+#define cogl_pipeline_set_uniform_matrix \
+        cogl_pipeline_set_uniform_matrix_EXP
+/**
+ * cogl_pipeline_set_uniform_matrix:
+ * @pipeline: A #CoglPipeline object
+ * @uniform_location: The uniform's location identifier
+ * @dimensions: The size of the matrix
+ * @count: The number of values to set
+ * @transpose: Whether to transpose the matrix
+ * @value: Pointer to the new values to set
+ *
+ * Sets new values for the uniform at @uniform_location. If this
+ * pipeline has a user program attached and is later used as a source
+ * for drawing, the given values will be assigned to the uniform which
+ * can be accessed from the shader's source. The value for
+ * @uniform_location should be retrieved from the string name of the
+ * uniform by calling cogl_pipeline_get_uniform_location().
+ *
+ * This function can be used to set any matrix type uniform, including
+ * matrix arrays. For example, to set a single mat4 uniform you would
+ * use 4 for @dimensions and 1 for @count. To set an array of 8
+ * mat3 values, you could use 3 for @dimensions and 8 for @count.
+ *
+ * If @transpose is %FALSE then the matrix is expected to be in
+ * column-major order or if it is %TRUE then the matrix is in
+ * row-major order. You can pass a #CoglMatrix by calling by passing
+ * the result of cogl_matrix_get_array() in @value and setting
+ * @transpose to %FALSE.
+ *
+ * Since: 2.0
+ * Stability: Unstable
+ */
+void
+cogl_pipeline_set_uniform_matrix (CoglPipeline *pipeline,
+                                  int uniform_location,
+                                  int dimensions,
+                                  int count,
+                                  gboolean transpose,
+                                  const float *value);
+
 #endif /* COGL_ENABLE_EXPERIMENTAL_API */
 
 G_END_DECLS