#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 <map>
#include <string>
+#include <vector>
+
+#include <assert.h>
+
+#include <Eigen/Core>
-#include <GL/gl.h>
+#include <GL/glew.h>
+#include "util.h"
+
+class EffectChain;
+class Node;
// Can alias on a float[2].
struct Point2D {
};
// 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);
+void set_uniform_mat3(GLuint glsl_program_num, const std::string &prefix, const std::string &key, const Eigen::Matrix3d &matrix);
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
+ // 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; }
- virtual bool needs_many_samples() const { return false; }
+
+ // 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 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
+ // 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; }
+ // 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; }
+
+ // 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);
+ }
+
+ // 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; }
+
+ // 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.
+ // If you do not want this behavior, you can override this function.
virtual std::string output_convenience_uniforms() const;
+
+ // Returns the GLSL fragment shader string for this effect.
virtual std::string output_fragment_shader() = 0;
- virtual void set_uniforms(GLuint glsl_program_num, const std::string& prefix, unsigned *sampler_num);
+ // Set all OpenGL state that this effect needs before rendering.
+ // The default implementation sets one uniform per registered parameter,
+ // but no other state.
+ //
+ // <sampler_num> is the first free texture sampler. If you want to use
+ // textures, you can bind a texture to GL_TEXTURE0 + <sampler_num>,
+ // 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);
- // 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);
+ // 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) 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;
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 <values>, 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);
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