X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=effect.h;h=fbe39d7274a421fd9f906ae809fdace3df7a8bc2;hb=b564238fa1293c01c77bcabe7b2de267f146ab24;hp=4f740f3cec0015910b4977642b1467570751c5e6;hpb=6602e2b9d5e5a44c0f075fe083ecc26feb10c173;p=movit

diff --git a/effect.h b/effect.h
index 4f740f3..fbe39d7 100644
--- a/effect.h
+++ b/effect.h
@@ -10,7 +10,7 @@
 // effect instance; use the macro PREFIX() around your identifiers to
 // automatically prepend that prefix.
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <assert.h>
 #include <stddef.h>
 #include <map>
@@ -18,6 +18,8 @@
 
 #include "defs.h"
 
+namespace movit {
+
 class EffectChain;
 class Node;
 
@@ -159,12 +161,47 @@ public:
 	// needs mipmaps, you will also get them).
 	virtual bool needs_mipmaps() const { return false; }
 
+	// Whether there is a direct correspondence between input and output
+	// texels. Specifically, the effect must not:
+	//
+	//   1. Try to sample in the border (ie., outside the 0.0 to 1.0 area).
+	//   2. Try to sample between texels.
+	//   3. Sample with an x- or y-derivative different from -1 or 1.
+	//      (This also means needs_mipmaps() and one_to_one_sampling()
+	//      together would make no sense.)
+	//
+	// The most common case for this would be an effect that has an exact
+	// 1:1-correspondence between input and output texels, e.g. SaturationEffect.
+	// However, more creative things, like mirroring/flipping or padding,
+	// would also be allowed.
+	//
+	// The primary gain from setting this is that you can sample directly
+	// from an effect that changes output size (see changes_output_size() below),
+	// without going through a bounce texture. It won't work for effects that
+	// set sets_virtual_output_size(), though.
+	//
+	// Does not make a lot of sense together with needs_texture_bounce().
+	virtual bool one_to_one_sampling() 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()).
+	// its input(s) (see inform_input_size(), below). See also
+	// sets_virtual_output_size() below.
 	virtual bool changes_output_size() const { return false; }
 
+	// Whether your get_output_size() function (see below) intends to ever set
+	// virtual_width different from width, or similar for height.
+	// It does not make sense to set this to true if changes_output_size() is false.
+	virtual bool sets_virtual_output_size() const { return changes_output_size(); }
+
+	// Whether this effect is effectively sampling from a a single texture.
+	// If so, it will override needs_texture_bounce(); however, there are also
+	// two demands it needs to fulfill:
+	//
+	//  1. It needs to be an Input, ie. num_inputs() == 0.
+	//  2. It needs to allocate exactly one sampler in set_gl_state(),
+	//     and allow dependent effects to change that sampler state.
+	virtual bool is_single_texture() const { return false; }
+
 	// If changes_output_size() is true, you must implement this to tell
 	// the framework what output size you want. Also, you can set a
 	// virtual width/height, which is the size the next effect (if any)
@@ -196,6 +233,12 @@ public:
 	// if you have several, they will be INPUT1(), INPUT2(), and so on.
 	virtual unsigned num_inputs() const { return 1; }
 
+	// Inform the effect that it has been just added to the EffectChain.
+	// The primary use for this is to store the ResourcePool uesd by
+	// the chain; for modifications to it, rewrite_graph() below
+	// is probably a better fit.
+	virtual void inform_added(EffectChain *chain) {}
+
 	// 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
@@ -265,4 +308,6 @@ private:
 	std::map<std::string, float *> params_vec4;
 };
 
+}  // namespace movit
+
 #endif // !defined(_MOVIT_EFFECT_H)