X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=effect_chain.h;h=c292b38b4a0b85642d8d5b7970117a5ae64b11c3;hp=22f0b96c6e4eabc807c8bf57a75b70516c3a8cda;hb=65c6584f77bff0af0c8e38d1ac90298bcd55e9ac;hpb=88003f99c7ef12ed895e504d41c6d528c3fda78d diff --git a/effect_chain.h b/effect_chain.h index 22f0b96..c292b38 100644 --- a/effect_chain.h +++ b/effect_chain.h @@ -99,6 +99,19 @@ enum OutputOrigin { 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: @@ -165,11 +178,24 @@ struct Phase { std::vector effects; // In order. unsigned output_width, output_height, virtual_output_width, virtual_output_height; + // Whether this phase is compiled as a compute shader, ie., the last effect is + // marked as one. + bool is_compute_shader; + + // If , which image unit the output buffer is bound to. + // This is used as source for a Uniform below. + int outbuf_image_unit; + + // These are used in transforming from unnormalized to normalized coordinates + // in compute shaders. + Point2D inv_output_size, output_texcoord_adjust; + // 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_image2d; std::vector > uniforms_sampler2d; std::vector > uniforms_bool; std::vector > uniforms_int; @@ -246,23 +272,46 @@ public: } 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). + // Adds an RGBA output. Note that you can have at most one RGBA output and two + // Y'CbCr outputs (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). + // Adds an YCbCr output. Note that you can only have at most two Y'CbCr + // outputs, and they must have the same and . + // (This limitation may be lifted in the future, to allow e.g. simultaneous + // 8- and 10-bit output. Currently, multiple Y'CbCr outputs are only + // useful in some very limited circumstances, like if one texture goes + // to some place you cannot easily read from later.) + // + // Only 4:4:4 output is supported due to fragment shader limitations, + // so chroma_subsampling_x and chroma_subsampling_y must both be 1. + // should match the data type of the FBO you are rendering to, + // so that if you use 16-bit output (GL_UNSIGNED_SHORT), you will get + // 8-, 10- or 12-bit output correctly as determined by . + // Using e.g. ycbcr_format.num_levels == 1024 with GL_UNSIGNED_BYTE is + // nonsensical and invokes undefined behavior. // - // If you have both RGBA and Y'CbCr output, the RGBA output will come + // If you have both RGBA and Y'CbCr output(s), 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); + YCbCrOutputSplitting output_splitting = YCBCR_OUTPUT_INTERLEAVED, + GLenum output_type = GL_UNSIGNED_BYTE); + + // Change Y'CbCr output format. (This can be done also after finalize()). + // Note that you are not allowed to change subsampling parameters; + // however, you can change the color space parameters, ie., + // luma_coefficients, full_range and num_levels. + void change_ycbcr_output_format(const YCbCrFormat &ycbcr_format); // Set number of output bits, to scale the dither. // 8 is the right value for most outputs. + // + // Special note for 10- and 12-bit Y'CbCr packed into GL_UNSIGNED_SHORT: + // This is relative to the actual output, not the logical one, so you should + // specify 16 here, not 10 or 12. + // // The default, 0, is a special value that means no dither. void set_dither_bits(unsigned num_bits) { @@ -277,6 +326,46 @@ public: 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 of 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. @@ -288,7 +377,9 @@ public: void reset_phase_timing(); void print_phase_timing(); - //void render(unsigned char *src, unsigned char *dst); + // Note: If you already know the width and height of the viewport, + // calling render_to_fbo() directly will be slightly more efficient, + // as it saves it from getting it from OpenGL. void render_to_screen() { render_to_fbo(0, 0, 0); @@ -368,7 +459,6 @@ private: // 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); @@ -422,22 +512,28 @@ private: void fix_output_gamma(); void add_ycbcr_conversion_if_needed(); void add_dither_if_needed(); + void add_dummy_effect_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. + bool output_color_rgba; + int num_output_color_ycbcr; // Max 2. + YCbCrFormat output_ycbcr_format; // If num_output_color_ycbcr is > 0. + GLenum output_ycbcr_type; // If num_output_color_ycbcr is > 0. + YCbCrOutputSplitting output_ycbcr_splitting[2]; // If num_output_color_ycbcr is > N. std::vector nodes; std::map node_map; Effect *dither_effect; + Node *ycbcr_conversion_effect_node; 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;