X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect.h;h=9d95705f6a66ce344a54bd18eb83154018d85c35;hp=397d3643975545b94fca94aa5eed58aff8ee4c85;hb=56ff92c5828a143595eeb7a1906418cc30668f9d;hpb=879854382e1f6db14812cd6bd5390ca01f4b1d5a diff --git a/effect.h b/effect.h index 397d364..9d95705 100644 --- a/effect.h +++ b/effect.h @@ -1,5 +1,5 @@ -#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. @@ -10,13 +10,18 @@ // effect instance; use the macro PREFIX() around your identifiers to // automatically prepend that prefix. +#include +#include +#include #include #include -#include -#include +#include "defs.h" + +namespace movit { class EffectChain; +class Node; // Can alias on a float[2]. struct Point2D { @@ -34,17 +39,23 @@ struct RGBTriplet { float r, g, b; }; -// 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_float_array(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values, size_t num_values); -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_array(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const float *values, size_t num_values); +// Can alias on a float[4]. +struct RGBATuple { + RGBATuple(float r, float g, float b, float a) + : r(r), g(g), b(b), a(a) {} + + float r, g, b, a; +}; class Effect { -public: +public: + virtual ~Effect() {} + + // An identifier for this type of effect, mostly used for debug output + // (but some special names, like "ColorspaceConversionEffect", holds special + // meaning). Same as the class name is fine. + virtual std::string effect_type_id() const = 0; + // Whether this effects expects its input (and output) to be in // linear gamma, ie. without an applied gamma curve. Most effects // will want this, although the ones that never actually look at @@ -60,9 +71,65 @@ public: // set of RGB primaries; you would currently not get YCbCr // or something similar). // - // Again, most effects will want this. + // Again, most effects will want this, but you can set it to false + // if you process each channel independently, equally _and_ + // in a linear fashion. virtual bool needs_srgb_primaries() const { return true; } + // How this effect handles alpha, ie. what it outputs in its + // alpha channel. The choices are basically blank (alpha is always 1.0), + // premultiplied and postmultiplied. + // + // Premultiplied alpha is when the alpha value has been be multiplied + // into the three color components, so e.g. 100% red at 50% alpha + // would be (0.5, 0.0, 0.0, 0.5) instead of (1.0, 0.0, 0.0, 0.5) + // as it is stored in most image formats (postmultiplied alpha). + // The multiplication is taken to have happened in linear light. + // 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_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- or postmultiplied) for all inputs, although most likely, + // you will want to combine them in a premultiplied fashion anyway + // in that case. + enum AlphaHandling { + // Always outputs blank alpha (ie. alpha=1.0). Only appropriate + // for inputs that do not output an alpha channel. + // Blank alpha is special in that it can be treated as both + // 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_PREMULTIPLIED_ALPHA, + + // 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 (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 thare have alpha != 1.0. + // + // Does not make sense for inputs. + DONT_CARE_ALPHA_TYPE, + }; + 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 // input from other effects, but will store the results of the @@ -77,7 +144,7 @@ public: // 2. You rely on previous effects, possibly including gamma // expansion, to happen pre-filtering instead of post-filtering. // (This is only relevant if you actually need the filtering; if - // you sample on whole input pixels only, it makes no difference.) + // you sample 1:1 between pixels and texels, it makes no difference.) // // Note that in some cases, you might get post-filtered gamma expansion // even when setting this option. More specifically, if you are the @@ -94,11 +161,71 @@ public: // needs mipmaps, you will also get them). virtual bool needs_mipmaps() const { return false; } - // Requests that this effect adds itself to the given effect chain. - // For most effects, the default will be fine, but for effects that - // consist of multiple passes, it is often useful to replace this - // with something that adds completely different things to the chain. - virtual void add_self_to_effect_chain(EffectChain *graph, Effect *input); + // 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()). + virtual bool changes_output_size() const { return false; } + + // 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 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) + // will _think_ your data is in. This is primarily useful if you are + // relying on getting OpenGL's bilinear resizing for free; otherwise, + // your virtual_width/virtual_height should be the same as width/height. + // + // Note that it is explicitly allowed to change width and height + // from frame to frame; EffectChain will reallocate textures as needed. + virtual void get_output_size(unsigned *width, unsigned *height, + unsigned *virtual_width, unsigned *virtual_height) const { + assert(false); + } + + // 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. + // + // Note that in some cases, an input might not have a single well-defined + // resolution (for instance if you fade between two inputs with + // different resolutions). In this case, you will get width=0 and height=0 + // for that input. If you cannot handle that, you will need to set + // needs_texture_bounce() to true, which will force a render to a single + // given resolution before you get the input. + virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height) {} + + // How many inputs this effect will take (a fixed number). + // If you have only one input, it will be called INPUT() in GLSL; + // 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 + // (for instance, two passes). The effect is given to its own + // pointer, and it can add new ones (by using add_node() + // and connect_node()) as it sees fit. This is called at + // EffectChain::finalize() time, when the entire graph is known, + // in the order that the effects were originally added. + // + // Note that if the effect wants to take itself entirely out + // of the chain, it must set “disabled” to true and then disconnect + // 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. @@ -108,24 +235,27 @@ public: // Returns the GLSL fragment shader string for this effect. virtual std::string output_fragment_shader() = 0; - // Set all uniforms the shader needs in the current GL context. - // The default implementation sets one uniform per registered parameter. + // Set all OpenGL state that this effect needs before rendering. + // The default implementation sets one uniform per registered parameter, + // but no other state. // // is the first free texture sampler. If you want to use // textures, you can bind a texture to GL_TEXTURE0 + , // and then increment the number (so that the next effect in the chain // will use a different sampler). - // - // NOTE: Currently this is also abused a bit to set other GL state - // the effect might need. - virtual void set_uniforms(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num); + virtual void set_gl_state(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num); + + // If you set any special OpenGL state in set_gl_state(), you can clear it + // after rendering here. The default implementation does nothing. + virtual void clear_gl_state(); // Set a parameter; intended to be called from user code. // Neither of these take ownership of the pointer. - virtual bool set_int(const std::string&, int value); - virtual bool set_float(const std::string &key, float value); - virtual bool set_vec2(const std::string &key, const float *values); - virtual bool set_vec3(const std::string &key, const float *values); + virtual bool set_int(const std::string&, int value) MUST_CHECK_RESULT; + virtual bool set_float(const std::string &key, float value) MUST_CHECK_RESULT; + virtual bool set_vec2(const std::string &key, const float *values) MUST_CHECK_RESULT; + virtual bool set_vec3(const std::string &key, const float *values) MUST_CHECK_RESULT; + virtual bool set_vec4(const std::string &key, const float *values) MUST_CHECK_RESULT; protected: // Register a parameter. Whenever set_*() is called with the same key, @@ -138,35 +268,20 @@ protected: // Thus, ints that you register will _not_ be converted to GLSL uniforms. void register_int(const std::string &key, int *value); - // These correspond directly to float/vec2/vec3 in GLSL. + // 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). - // - // Note that if you change the contents of , 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; - }; - std::map params_int; std::map params_float; std::map params_vec2; std::map params_vec3; - std::map params_tex_1d; + std::map params_vec4; }; -#endif // !defined(_EFFECT_H) +} // namespace movit + +#endif // !defined(_MOVIT_EFFECT_H)