-#ifndef _EFFECT_H
-#define _EFFECT_H 1
+#ifndef _MOVIT_EFFECT_H
+#define _MOVIT_EFFECT_H 1
// Effect is the base class for every effect. It basically represents a single
// GLSL function, with an optional set of user-settable parameters.
// effect instance; use the macro PREFIX() around your identifiers to
// automatically prepend that prefix.
+#include <epoxy/gl.h>
+#include <assert.h>
+#include <stddef.h>
#include <map>
#include <string>
#include <vector>
-
-#include <assert.h>
-
#include <Eigen/Core>
-#include <GL/glew.h>
-#include "util.h"
+#include "defs.h"
+
+namespace movit {
class EffectChain;
class Node;
// Can alias on a float[2].
struct Point2D {
+ Point2D() {}
Point2D(float x, float y)
: x(x), y(y) {}
// Can alias on a float[3].
struct RGBTriplet {
+ RGBTriplet() {}
RGBTriplet(float r, float g, float b)
: r(r), g(g), b(b) {}
};
// Can alias on a float[4].
-struct RGBATriplet {
- RGBATriplet(float r, float g, float b, float a)
+struct RGBATuple {
+ RGBATuple() {}
+ RGBATuple(float r, float g, float b, float a)
: r(r), g(g), b(b), a(a) {}
float r, g, b, a;
};
-// Convenience functions that deal with prepending the prefix.
-GLint get_uniform_location(GLuint glsl_program_num, const std::string &prefix, const std::string &key);
-void set_uniform_int(GLuint glsl_program_num, const std::string &prefix, const std::string &key, int value);
-void set_uniform_float(GLuint glsl_program_num, const std::string &prefix, const std::string &key, float value);
-void set_uniform_vec2(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values);
-void set_uniform_vec3(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values);
-void set_uniform_vec4(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values);
-void set_uniform_vec4_array(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values, size_t num_values);
-void set_uniform_mat3(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const Eigen::Matrix3d &matrix);
+// Represents a registered uniform.
+template<class T>
+struct Uniform {
+ std::string name; // Without prefix.
+ const T *value; // Owner by the effect.
+ size_t num_values; // Number of elements; for arrays only. _Not_ the vector length.
+ std::string prefix; // Filled in only after phases have been constructed.
+ GLint location; // Filled in only after phases have been constructed. -1 if no location.
+};
class Effect {
public:
// This is the most natural format for processing, and the default in
// most of Movit (just like linear light is).
//
- // If you set INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED, all of your inputs
+ // If you set INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA or
+ // INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK, all of your inputs
// (if any) are guaranteed to also be in premultiplied alpha.
// Otherwise, you can get postmultiplied or premultiplied alpha;
// you won't know. If you have multiple inputs, you will get the same
// pre- and postmultiplied.
OUTPUT_BLANK_ALPHA,
+ // Always outputs postmultiplied alpha. Only appropriate for inputs.
+ OUTPUT_POSTMULTIPLIED_ALPHA,
+
// Always outputs premultiplied alpha. As noted above,
// you will then also get all inputs in premultiplied alpha.
// If you set this, you should also set needs_linear_light().
- INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED,
+ INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA,
- // Always outputs postmultiplied alpha. Only appropriate for inputs.
- OUTPUT_ALPHA_POSTMULTIPLIED,
+ // Like INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA, but also guarantees
+ // that if you get blank alpha in, you also keep blank alpha out.
+ // This is a somewhat weaker guarantee than DONT_CARE_ALPHA_TYPE,
+ // but is still useful in many situations, and appropriate when
+ // e.g. you don't touch alpha at all.
+ //
+ // Does not make sense for inputs.
+ INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK,
- // Keeps the type of alpha unchanged from input to output.
- // Usually appropriate if you process all color channels
- // in a linear fashion, and do not change alpha.
+ // Keeps the type of alpha (premultiplied, postmultiplied, blank)
+ // unchanged from input to output. Usually appropriate if you
+ // process all color channels in a linear fashion, do not change
+ // alpha, and do not produce any new pixels that have alpha != 1.0.
//
// Does not make sense for inputs.
DONT_CARE_ALPHA_TYPE,
};
- virtual AlphaHandling alpha_handling() const { return INPUT_AND_OUTPUT_ALPHA_PREMULTIPLIED; }
+ virtual AlphaHandling alpha_handling() const { return INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA; }
// Whether this effect expects its input to come directly from
// a texture. If this is true, the framework will not chain the
// needs mipmaps, you will also get them).
virtual bool needs_mipmaps() const { return false; }
+ // Whether there is a direct correspondence between input and output
+ // texels. Specifically, the effect must not:
+ //
+ // 1. Try to sample in the border (ie., outside the 0.0 to 1.0 area).
+ // 2. Try to sample between texels.
+ // 3. Sample with an x- or y-derivative different from -1 or 1.
+ // (This also means needs_mipmaps() and one_to_one_sampling()
+ // together would make no sense.)
+ //
+ // The most common case for this would be an effect that has an exact
+ // 1:1-correspondence between input and output texels, e.g. SaturationEffect.
+ // However, more creative things, like mirroring/flipping or padding,
+ // would also be allowed.
+ //
+ // The primary gain from setting this is that you can sample directly
+ // from an effect that changes output size (see changes_output_size() below),
+ // without going through a bounce texture. It won't work for effects that
+ // set sets_virtual_output_size(), though.
+ //
+ // Does not make a lot of sense together with needs_texture_bounce().
+ virtual bool one_to_one_sampling() const { return false; }
+
// Whether this effect wants to output to a different size than
- // its input(s) (see inform_input_size(), below). If you set this to
- // true, the output will be bounced to a texture (similarly to if the
- // next effect set needs_texture_bounce()).
+ // its input(s) (see inform_input_size(), below). See also
+ // sets_virtual_output_size() below.
virtual bool changes_output_size() const { return false; }
+ // Whether your get_output_size() function (see below) intends to ever set
+ // virtual_width different from width, or similar for height.
+ // It does not make sense to set this to true if changes_output_size() is false.
+ virtual bool sets_virtual_output_size() const { return changes_output_size(); }
+
+ // Whether this effect is effectively sampling from a a single texture.
+ // If so, it will override needs_texture_bounce(); however, there are also
+ // two demands it needs to fulfill:
+ //
+ // 1. It needs to be an Input, ie. num_inputs() == 0.
+ // 2. It needs to allocate exactly one sampler in set_gl_state(),
+ // and allow dependent effects to change that sampler state.
+ virtual bool is_single_texture() const { return false; }
+
+ // If set, this effect should never be bounced to an output, even if a
+ // dependent effect demands texture bounce.
+ //
+ // Note that setting this can invoke undefined behavior, up to and including crashing,
+ // so you should only use it if you have deep understanding of your entire chain
+ // and Movit's processing of it. The most likely use case is if you have an input
+ // that's cheap to compute but not a single texture (e.g. YCbCrInput), and want
+ // to run a ResampleEffect directly from it. Normally, this would require a bounce,
+ // but it's faster not to. (However, also note that in this case, effective texel
+ // subpixel precision will be too optimistic, since chroma is already subsampled.)
+ //
+ // Has no effect if is_single_texture() is set.
+ virtual bool override_disable_bounce() const { return false; }
+
// If changes_output_size() is true, you must implement this to tell
// the framework what output size you want. Also, you can set a
// virtual width/height, which is the size the next effect (if any)
assert(false);
}
+ // Whether this effect uses a compute shader instead of a regular fragment shader.
+ // Compute shaders are more flexible in that they can have multiple outputs
+ // for each invocation and also communicate between instances (by using shared
+ // memory within each group), but are not universally supported. The typical
+ // pattern would be to check movit_compute_shaders_supported and rewrite the
+ // graph to use a compute shader effect instead of a regular effect if it is
+ // available, in order to get better performance. Since compute shaders can reuse
+ // loads (again typically through shared memory), using needs_texture_bounce()
+ // is usually not needed, although it is allowed; the best candidates for compute
+ // shaders are typically those that sample many times from their input
+ // but can reuse those loads across neighboring instances.
+ //
+ // Compute shaders commonly work with unnormalized texture coordinates
+ // (where coordinates are integers [0..W) and [0..H)), whereas the rest
+ // of Movit, including any inputs you may want to sample from, works
+ // with normalized coordinates ([0..1)). Movit gives you uniforms
+ // PREFIX(inv_output_size) and PREFIX(output_texcoord_adjust) that you
+ // can use to transform unnormalized to normalized, as well as a macro
+ // NORMALIZE_TEXTURE_COORDS(vec2) that does it for you.
+ //
+ // Since compute shaders have flexible output, it is difficult to chain other
+ // effects after them in the same phase, and thus, they will always be last.
+ // (This limitation may be lifted for the special case of one-to-one effects
+ // in the future.) Furthermore, they cannot write to the framebuffer, just to
+ // textures, so Movit may have to insert an extra phase just to do the output
+ // from a texture to the screen in some cases. However, this is transparent
+ // to both the effect and the user.
+ virtual bool is_compute_shader() const { return false; }
+
+ // For a compute shader (see the previous member function), what dimensions
+ // it should be invoked over. Called every frame, before uniforms are set
+ // (so you are allowed to update uniforms based from this call).
+ virtual void get_compute_dimensions(unsigned output_width, unsigned output_height,
+ unsigned *x, unsigned *y, unsigned *z) const {
+ *x = output_width;
+ *y = output_height;
+ *z = 1;
+ }
+
// Tells the effect the resolution of each of its input.
// This will be called every frame, and always before get_output_size(),
// so you can change your output size based on the input if so desired.
// if you have several, they will be INPUT1(), INPUT2(), and so on.
virtual unsigned num_inputs() const { return 1; }
+ // Inform the effect that it has been just added to the EffectChain.
+ // The primary use for this is to store the ResourcePool uesd by
+ // the chain; for modifications to it, rewrite_graph() below
+ // is probably a better fit.
+ virtual void inform_added(EffectChain *chain) {}
+
// Let the effect rewrite the effect chain as it sees fit.
// Most effects won't need to do this, but this is very useful
// if you have an effect that consists of multiple sub-effects
// itself from all other effects.
virtual void rewrite_graph(EffectChain *graph, Node *self) {}
- // Outputs one GLSL uniform declaration for each registered parameter
- // (see below), with the right prefix prepended to each uniform name.
- // If you do not want this behavior, you can override this function.
- virtual std::string output_convenience_uniforms() const;
-
// Returns the GLSL fragment shader string for this effect.
virtual std::string output_fragment_shader() = 0;
protected:
// Register a parameter. Whenever set_*() is called with the same key,
// it will update the value in the given pointer (typically a pointer
- // to some private member variable in your effect).
+ // to some private member variable in your effect). It will also
+ // register a uniform of the same name (plus an arbitrary prefix
+ // which you can access using the PREFIX macro) that you can access.
//
// Neither of these take ownership of the pointer.
- // int is special since GLSL pre-1.30 doesn't have integer uniforms.
- // Thus, ints that you register will _not_ be converted to GLSL uniforms.
+ // These correspond directly to int/float/vec2/vec3/vec4 in GLSL.
void register_int(const std::string &key, int *value);
-
- // These correspond directly to float/vec2/vec3/vec4 in GLSL.
void register_float(const std::string &key, float *value);
void register_vec2(const std::string &key, float *values);
void register_vec3(const std::string &key, float *values);
void register_vec4(const std::string &key, float *values);
- // This will register a 1D texture, which will be bound to a sampler
- // when your GLSL code runs (so it corresponds 1:1 to a sampler2D uniform
- // in GLSL).
+ // Register uniforms, such that they will automatically be set
+ // before the shader runs. This is more efficient than set_uniform_*
+ // in effect_util.h, because it doesn't need to do name lookups
+ // every time. Also, in the future, it will use uniform buffer objects
+ // (UBOs) if available to reduce the number of calls into the driver.
//
- // Note that if you change the contents of <values>, you will need to
- // call invalidate_1d_texture() to have the picture re-uploaded on the
- // next frame. This is in contrast to all the other parameters, which are
- // set anew every frame.
- void register_1d_texture(const std::string &key, float *values, size_t size);
- void invalidate_1d_texture(const std::string &key);
-
-private:
- struct Texture1D {
- float *values;
- size_t size;
- bool needs_update;
- GLuint texture_num;
- };
+ // May not be called after output_fragment_shader() has returned.
+ // The pointer must be valid for the entire lifetime of the Effect,
+ // since the value is pulled from it each execution. The value is
+ // guaranteed to be read after set_gl_state() for the effect has
+ // returned, so you can safely update its value from there.
+ //
+ // Note that this will also declare the uniform in the shader for you,
+ // so you should not do that yourself. (This is so it can be part of
+ // the right uniform block.) However, it is probably a good idea to
+ // have a commented-out declaration so that it is easier to see the
+ // type and thus understand the shader on its own.
+ //
+ // Calling register_* will automatically imply register_uniform_*,
+ // except for register_int as noted above.
+ void register_uniform_sampler2d(const std::string &key, const int *value);
+ void register_uniform_bool(const std::string &key, const bool *value);
+ void register_uniform_int(const std::string &key, const int *value); // Note: Requires GLSL 1.30 or newer.
+ void register_uniform_float(const std::string &key, const float *value);
+ void register_uniform_vec2(const std::string &key, const float *values);
+ void register_uniform_vec3(const std::string &key, const float *values);
+ void register_uniform_vec4(const std::string &key, const float *values);
+ void register_uniform_float_array(const std::string &key, const float *values, size_t num_values);
+ void register_uniform_vec2_array(const std::string &key, const float *values, size_t num_values);
+ void register_uniform_vec3_array(const std::string &key, const float *values, size_t num_values);
+ void register_uniform_vec4_array(const std::string &key, const float *values, size_t num_values);
+ void register_uniform_mat3(const std::string &key, const Eigen::Matrix3d *matrix);
+private:
std::map<std::string, int *> params_int;
std::map<std::string, float *> params_float;
std::map<std::string, float *> params_vec2;
std::map<std::string, float *> params_vec3;
std::map<std::string, float *> params_vec4;
- std::map<std::string, Texture1D> params_tex_1d;
+
+ // Picked out by EffectChain during finalization.
+ std::vector<Uniform<int>> uniforms_image2d;
+ std::vector<Uniform<int>> uniforms_sampler2d;
+ std::vector<Uniform<bool>> uniforms_bool;
+ std::vector<Uniform<int>> uniforms_int;
+ std::vector<Uniform<float>> uniforms_float;
+ std::vector<Uniform<float>> uniforms_vec2;
+ std::vector<Uniform<float>> uniforms_vec3;
+ std::vector<Uniform<float>> uniforms_vec4;
+ std::vector<Uniform<float>> uniforms_float_array;
+ std::vector<Uniform<float>> uniforms_vec2_array;
+ std::vector<Uniform<float>> uniforms_vec3_array;
+ std::vector<Uniform<float>> uniforms_vec4_array;
+ std::vector<Uniform<Eigen::Matrix3d>> uniforms_mat3;
+ friend class EffectChain;
};
-#endif // !defined(_EFFECT_H)
+} // namespace movit
+
+#endif // !defined(_MOVIT_EFFECT_H)