X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect.h;h=d14176b2b1f4dc5f74f56388766cdfb2d5d14362;hp=32d8f402f09598c88f2f4a989a9c70ecdead7206;hb=fe785e6f62ab58ef05972850d9275005794505b7;hpb=96a1cff51a8b7dc45ebe725e0d0685eecce31331 diff --git a/effect.h b/effect.h index 32d8f40..d14176b 100644 --- a/effect.h +++ b/effect.h @@ -1,11 +1,23 @@ #ifndef _EFFECT_H #define _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. +// +// A note on naming: Since all effects run in the same GLSL namespace, +// you can't use any name you want for global variables (e.g. uniforms). +// The framework assigns a prefix to you which will be unique for each +// effect instance; use the macro PREFIX() around your identifiers to +// automatically prepend that prefix. + #include #include +#include #include +class EffectChain; + // Can alias on a float[2]. struct Point2D { Point2D(float x, float y) @@ -23,40 +35,147 @@ struct RGBTriplet { }; // 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); class Effect { public: - virtual bool needs_linear_light() { return true; } - virtual bool needs_srgb_primaries() { return true; } - virtual bool needs_many_samples() { return false; } - virtual bool needs_mipmaps() { return false; } + // 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 + // the pixels, e.g. mirror, won't need to care, and can set this + // to false. If so, the input gamma will be undefined. + // + // Also see the note on needs_texture_bounce(), below. + virtual bool needs_linear_light() const { return true; } + + // Whether this effect expects its input to be in the sRGB + // color space, ie. use the sRGB/Rec. 709 RGB primaries. + // (If not, it would typically come in as some slightly different + // set of RGB primaries; you would currently not get YCbCr + // or something similar). + // + // 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; } + + // 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 + // chain to a temporary (RGBA fp16) texture and let this effect + // sample directly from that. + // + // There are two good reasons why you might want to set this: + // + // 1. You are sampling more than once from the input, + // in which case computing all the previous steps might + // be more expensive than going to a memory intermediate. + // 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.) + // + // Note that in some cases, you might get post-filtered gamma expansion + // even when setting this option. More specifically, if you are the + // first effect in the chain, and the GPU is doing sRGB gamma + // expansion, it is undefined (from OpenGL's side) whether expansion + // happens pre- or post-filtering. For most uses, however, + // either will be fine. + virtual bool needs_texture_bounce() const { return false; } + + // Whether this effect expects mipmaps or not. If you set this to + // true, you will be sampling with bilinear filtering; if not, + // you could be sampling with simple linear filtering and no mipmaps + // (although there is no guarantee; if a different effect in the chain + // needs mipmaps, you will also get them). + virtual bool needs_mipmaps() const { return false; } + + // 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; } + + // 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, const std::vector &inputs); - virtual std::string output_convenience_uniforms(); - virtual std::string output_glsl() = 0; + // 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; - virtual void set_uniforms(GLuint glsl_program_num, const std::string& prefix); + // Returns the GLSL fragment shader string for this effect. + virtual std::string output_fragment_shader() = 0; - // Neither of these take ownership. - bool set_int(const std::string&, int value); - bool set_float(const std::string &key, float value); - bool set_vec2(const std::string &key, const float *values); - bool set_vec3(const std::string &key, const float *values); + // 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). + 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); protected: - // Neither of these take ownership. + // 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). + // + // 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. void register_int(const std::string &key, int *value); + + // These correspond directly to float/vec2/vec3 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); + + // 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; }; #endif // !defined(_EFFECT_H)