X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect.h;h=c016a55070c2fb63585cd381c46c9e69a4de77a4;hp=f495867a42029128eaa7140747508fa76ebce696;hb=3d1f6c11c53cd9d3d5c1fb60f4accf050b7f135e;hpb=b77dca09201f3373c5466d695338e1e29406072b diff --git a/effect.h b/effect.h index f495867..c016a55 100644 --- a/effect.h +++ b/effect.h @@ -14,7 +14,11 @@ #include #include -#include +#include + +#include "opengl.h" + +class EffectChain; // Can alias on a float[2]. struct Point2D { @@ -49,7 +53,7 @@ public: // 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_many_samples(), below. + // 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 @@ -58,22 +62,34 @@ 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; } - // Whether this effect expects to be sampling many times from - // its input. If this is true, the framework will not chain the + // 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. // - // Note that if you do _not_ set this, and do not sample on - // whole pixels (ie. you request linear filtering), it is undefined - // whether that filtering happen in linear gamma or not. - // It _could_ be (for instance in the case where the input is sRGB - // and your GPU applies gamma expansion before filtering), but you - // have no such guarantee. For most uses, however, this will be fine. - virtual bool needs_many_samples() const { return false; } + // 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, @@ -82,13 +98,31 @@ public: // needs mipmaps, you will also get them). virtual bool needs_mipmaps() const { return false; } + // Whether this effect wants to output to a different size than + // its input(s). 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; } + + // If changes_output_size() is true, you must implement this to tell + // the framework what output size you want. + // + // 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) const { + assert(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(std::vector *chain) { - chain->push_back(this); - } + virtual void add_self_to_effect_chain(EffectChain *graph, const std::vector &inputs); // Outputs one GLSL uniform declaration for each registered parameter // (see below), with the right prefix prepended to each uniform name. @@ -98,17 +132,19 @@ 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.