X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect_chain.h;h=918769b3872451576f329a5252568fc214889a03;hp=02906fe0b9885b0263db412a16b3b4d0fd540031;hb=dd74f9c467529f2bf68c97c1b8f2336f7abd7ff6;hpb=9e219b96e914b2e5709ba3c3345afdc3cf13a78d diff --git a/effect_chain.h b/effect_chain.h index 02906fe..918769b 100644 --- a/effect_chain.h +++ b/effect_chain.h @@ -16,15 +16,23 @@ // but if so, the threads' contexts need to be set up to share resources, since // the EffectChain holds textures and other OpenGL objects that are tied to the // context. +// +// Memory management (only relevant if you use multiple contexts): +// See corresponding comment in resource_pool.h. This holds even if you don't +// allocate your own ResourcePool, but let EffectChain hold its own. #include #include +#include #include #include #include #include +#include +#include "effect.h" #include "image_format.h" +#include "ycbcr.h" namespace movit { @@ -48,6 +56,62 @@ enum OutputAlphaFormat { OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED, }; +// RGBA output is nearly always packed; Y'CbCr, however, is often planar +// due to chroma subsampling. This enum controls how add_ycbcr_output() +// distributes the color channels between the fragment shader outputs. +// Obviously, anything except YCBCR_OUTPUT_INTERLEAVED will be meaningless +// unless you use render_to_fbo() and have an FBO with multiple render +// targets attached (the other outputs will be discarded). +enum YCbCrOutputSplitting { + // Only one output: Store Y'CbCr into the first three output channels, + // respectively, plus alpha. This is also called “chunked” or + // ”packed” mode. + YCBCR_OUTPUT_INTERLEAVED, + + // Store Y' and alpha into the first output (in the red and alpha + // channels; effect to the others is undefined), and Cb and Cr into + // the first two channels of the second output. This is particularly + // useful if you want to end up in a format like NV12, where all the + // Y' samples come first and then Cb and Cr come interlevaed afterwards. + // You will still need to do the chroma subsampling yourself to actually + // get down to NV12, though. + YCBCR_OUTPUT_SPLIT_Y_AND_CBCR, + + // Store Y' and alpha into the first output, Cb into the first channel + // of the second output and Cr into the first channel of the third output. + // (Effect on the other channels is undefined.) Essentially gives you + // 4:4:4 planar, or ”yuv444p”. + YCBCR_OUTPUT_PLANAR, +}; + +// Where (0,0) is taken to be in the output. If you want to render to an +// OpenGL screen, you should keep the default of bottom-left, as that is +// OpenGL's natural coordinate system. However, there are cases, such as if you +// render to an FBO and read the pixels back into some other system, where +// you'd want a top-left origin; if so, an additional flip step will be added +// at the very end (but done in a vertex shader, so it will have zero extra +// cost). +// +// Note that Movit's coordinate system in general consistently puts (0,0) in +// the top left for _input_, no matter what you set as output origin. +enum OutputOrigin { + OUTPUT_ORIGIN_BOTTOM_LEFT, + OUTPUT_ORIGIN_TOP_LEFT, +}; + +// Transformation to apply (if any) to pixel data in temporary buffers. +// See set_intermediate_format() below for more information. +enum FramebufferTransformation { + // The default; just store the value. This is what you usually want. + NO_FRAMEBUFFER_TRANSFORMATION, + + // If the values are in linear light, store sqrt(x) to the framebuffer + // instead of x itself, of course undoing it with x² on read. Useful as + // a rough approximation to the sRGB curve. (If the values are not in + // linear light, just store them as-is.) + SQUARE_ROOT_FRAMEBUFFER_TRANSFORMATION, +}; + // A node in the graph; basically an effect and some associated information. class Node { public: @@ -58,6 +122,10 @@ public: std::vector outgoing_links; std::vector incoming_links; + // For unit tests only. Do not use from other code. + // Will contain an arbitrary choice if the node is in multiple phases. + Phase *containing_phase; + private: // Logical size of the output of this effect, ie. the resolution // you would get if you sampled it as a texture. If it is undefined @@ -66,11 +134,6 @@ private: // they will be equal. unsigned output_width, output_height; - // If output goes to RTT, which phase it is in (otherwise unset). - // This is a bit ugly; we should probably fix so that Phase takes other - // phases as inputs, instead of Node. - Phase *phase; - // If the effect has is_single_texture(), or if the output went to RTT // and that texture has been bound to a sampler, the sampler number // will be stored here. @@ -84,25 +147,56 @@ private: Colorspace output_color_space; GammaCurve output_gamma_curve; AlphaType output_alpha_type; + bool needs_mipmaps; // Directly or indirectly. + + // Set if this effect, and all effects consuming output from this node + // (in the same phase) have one_to_one_sampling() set. + bool one_to_one_sampling; friend class EffectChain; }; // A rendering phase; a single GLSL program rendering a single quad. struct Phase { + Node *output_node; + GLuint glsl_program_num; // Owned by the resource_pool. + + // Position and texcoord attribute indexes, although it doesn't matter + // which is which, because they contain the same data. + std::set attribute_indexes; + bool input_needs_mipmaps; // Inputs are only inputs from other phases (ie., those that come from RTT); - // input textures are not counted here. - std::vector inputs; - + // input textures are counted as part of . + std::vector inputs; + // Bound sampler numbers for each input. Redundant in a sense + // (it always corresponds to the index), but we need somewhere + // to hold the value for the uniform. + std::vector input_samplers; std::vector effects; // In order. unsigned output_width, output_height, virtual_output_width, virtual_output_height; // Identifier used to create unique variables in GLSL. // Unique per-phase to increase cacheability of compiled shaders. std::map effect_ids; + + // Uniforms for this phase; combined from all the effects. + std::vector > uniforms_sampler2d; + std::vector > uniforms_bool; + std::vector > uniforms_int; + std::vector > uniforms_float; + std::vector > uniforms_vec2; + std::vector > uniforms_vec3; + std::vector > uniforms_vec4; + std::vector > uniforms_mat3; + + // For measurement of GPU time used. + std::list timer_query_objects_running; + std::list timer_query_objects_free; + uint64_t time_elapsed_ns; + uint64_t num_measured_iterations; }; class EffectChain { @@ -146,10 +240,40 @@ public: inputs.push_back(input3); return add_effect(effect, inputs); } + Effect *add_effect(Effect *effect, Effect *input1, Effect *input2, Effect *input3, Effect *input4) { + std::vector inputs; + inputs.push_back(input1); + inputs.push_back(input2); + inputs.push_back(input3); + inputs.push_back(input4); + return add_effect(effect, inputs); + } + Effect *add_effect(Effect *effect, Effect *input1, Effect *input2, Effect *input3, Effect *input4, Effect *input5) { + std::vector inputs; + inputs.push_back(input1); + inputs.push_back(input2); + inputs.push_back(input3); + inputs.push_back(input4); + inputs.push_back(input5); + return add_effect(effect, inputs); + } Effect *add_effect(Effect *effect, const std::vector &inputs); + // Adds an RGBA output. Note that you can have at most one RGBA output and one + // Y'CbCr output (see below for details). void add_output(const ImageFormat &format, OutputAlphaFormat alpha_format); + // Adds an YCbCr output. Note that you can only have one output. + // Currently, only chunked packed output is supported, and only 4:4:4 + // (so chroma_subsampling_x and chroma_subsampling_y must both be 1). + // + // If you have both RGBA and Y'CbCr output, the RGBA output will come + // in the last draw buffer. Also, and must be + // identical between the two. + void add_ycbcr_output(const ImageFormat &format, OutputAlphaFormat alpha_format, + const YCbCrFormat &ycbcr_format, + YCbCrOutputSplitting output_splitting = YCBCR_OUTPUT_INTERLEAVED); + // Set number of output bits, to scale the dither. // 8 is the right value for most outputs. // The default, 0, is a special value that means no dither. @@ -158,10 +282,65 @@ public: this->num_dither_bits = num_bits; } + // Set where (0,0) is taken to be in the output. The default is + // OUTPUT_ORIGIN_BOTTOM_LEFT, which is usually what you want + // (see OutputOrigin above for more details). + void set_output_origin(OutputOrigin output_origin) + { + this->output_origin = output_origin; + } + + // Set intermediate format for framebuffers used when we need to bounce + // to a temporary texture. The default, GL_RGBA16F, is good for most uses; + // it is precise, has good range, and is relatively efficient. However, + // if you need even more speed and your chain can do with some loss of + // accuracy, you can change the format here (before calling finalize). + // Calculations between bounce buffers are still in 32-bit floating-point + // no matter what you specify. + // + // Of special interest is GL_SRGB8_ALPHA8, which stores sRGB-encoded RGB + // and linear alpha; this is half the memory bandwidth og GL_RGBA16F, + // while retaining reasonable precision for typical image data. It will, + // however, cause some gamut clipping if your colorspace is far from sRGB, + // as it cannot represent values outside [0,1]. NOTE: If you construct + // a chain where you end up bouncing pixels in non-linear light + // (gamma different from GAMMA_LINEAR), this will be the wrong thing. + // However, it's hard to see how this could happen in a non-contrived + // chain; few effects ever need texture bounce or resizing without also + // combining multiple pixels, which really needs linear light and thus + // triggers a conversion before the bounce. + // + // If you don't need alpha (or can do with very little of it), GL_RGB10_A2 + // is even better, as it has two more bits for each color component. There + // is no GL_SRGB10, unfortunately, so on its own, it is somewhat worse than + // GL_SRGB8, but you can set to SQUARE_ROOT_FRAMEBUFFER_TRANSFORMATION, + // and sqrt(x) will be stored instead of x. This is a rough approximation to + // the sRGB curve, and reduces maximum error (in sRGB distance) by almost an + // order of magnitude, well below what you can get from 8-bit true sRGB. + // (Note that this strategy avoids the problem with bounced non-linear data + // above, since the square root is turned off in that case.) However, texture + // filtering will happen on the transformed values, so if you have heavy + // downscaling or the likes (e.g. mipmaps), you could get subtly bad results. + // You'll need to see which of the two that works the best for you in practice. + void set_intermediate_format( + GLenum intermediate_format, + FramebufferTransformation transformation = NO_FRAMEBUFFER_TRANSFORMATION) + { + this->intermediate_format = intermediate_format; + this->intermediate_transformation = transformation; + } + void finalize(); + // Measure the GPU time used for each actual phase during rendering. + // Note that this is only available if GL_ARB_timer_query + // (or, equivalently, OpenGL 3.3) is available. Also note that measurement + // will incur a performance cost, as we wait for the measurements to + // complete at the end of rendering. + void enable_phase_timing(bool enable); + void reset_phase_timing(); + void print_phase_timing(); - //void render(unsigned char *src, unsigned char *dst); void render_to_screen() { render_to_fbo(0, 0, 0); @@ -200,6 +379,13 @@ public: // single-sampler input, or from an RTT texture. GLenum get_input_sampler(Node *node, unsigned input_num) const; + // Whether input of corresponds to a single sampler + // (see get_input_sampler()). Normally, you should not need to call this; + // however, if the input Effect has set override_texture_bounce(), + // this will return false, and you could be flexible and check it first + // if you want. + GLenum has_input_sampler(Node *node, unsigned input_num) const; + // Get the current resource pool assigned to this EffectChain. // Primarily to let effects allocate textures as needed. // Any resources you get from the pool must be returned to the pool @@ -224,13 +410,25 @@ private: // output gamma different from GAMMA_LINEAR. void find_all_nonlinear_inputs(Node *effect, std::vector *nonlinear_inputs); - // Create a GLSL program computing the given effects in order. - Phase *compile_glsl_program(const std::vector &inputs, - const std::vector &effects); + // Create a GLSL program computing the effects for this phase in order. + void compile_glsl_program(Phase *phase); // Create all GLSL programs needed to compute the given effect, and all outputs - // that depends on it (whenever possible). - void construct_glsl_programs(Node *output); + // that depend on it (whenever possible). Returns the phase that has + // as the last effect. Also pushes all phases in order onto . + Phase *construct_phase(Node *output, std::map *completed_effects); + + // Execute one phase, ie. set up all inputs, effects and outputs, and render the quad. + void execute_phase(Phase *phase, bool last_phase, + std::set *bound__attribute_indices, + std::map *output_textures, + std::set *generated_mipmaps); + + // Set up uniforms for one phase. The program must already be bound. + void setup_uniforms(Phase *phase); + + // Set up the given sampler number for sampling from an RTT texture. + void setup_rtt_sampler(int sampler_num, bool use_mipmaps); // Output the current graph to the given file in a Graphviz-compatible format; // only useful for debugging. @@ -274,12 +472,17 @@ private: void fix_internal_gamma_by_asking_inputs(unsigned step); void fix_internal_gamma_by_inserting_nodes(unsigned step); void fix_output_gamma(); + void add_ycbcr_conversion_if_needed(); void add_dither_if_needed(); float aspect_nom, aspect_denom; ImageFormat output_format; OutputAlphaFormat output_alpha_format; + bool output_color_rgba, output_color_ycbcr; + YCbCrFormat output_ycbcr_format; // If output_color_ycbcr is true. + YCbCrOutputSplitting output_ycbcr_splitting; // If output_color_ycbcr is true. + std::vector nodes; std::map node_map; Effect *dither_effect; @@ -287,11 +490,17 @@ private: std::vector inputs; // Also contained in nodes. std::vector phases; + GLenum intermediate_format; + FramebufferTransformation intermediate_transformation; unsigned num_dither_bits; + OutputOrigin output_origin; bool finalized; + GLuint vbo; // Contains vertex and texture coordinate data. ResourcePool *resource_pool; bool owns_resource_pool; + + bool do_phase_timing; }; } // namespace movit