X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=padding_effect.h;h=4925764eaa01e7596b35daed9d103c2d467ae0b4;hp=fdefbe0fe1a7b0fe329ed094bacaf3065b113697;hb=61f62ac697eaa44f6c51bf43793eb4dbdf7b9fce;hpb=e92a5ffa19eb67b4db5af1db8559630139073668

diff --git a/padding_effect.h b/padding_effect.h
index fdefbe0..4925764 100644
--- a/padding_effect.h
+++ b/padding_effect.h
@@ -5,18 +5,28 @@
 // (although the latter is implemented slightly less efficiently, and you cannot both
 // pad and crop in the same effect).
 //
-// The source image is cut off at the texel borders (so there is no interpolation
-// outside them), and then given a user-specific color; by default, full transparent.
+// The source image is cut off at the texture border, and then given a user-specific color;
+// by default, full transparent. You can give a fractional border size (non-integral
+// "top" or "left" offset) if you wish, which will give you linear interpolation of
+// both pixel data of and the border. Furthermore, you can offset where the border falls
+// by using the "border_offset_{top,bottom,left,right}" settings; this is particularly
+// useful if you use ResampleEffect earlier in the chain for high-quality fractional-pixel
+// translation and just want PaddingEffect to get the border right.
 //
 // The border color is taken to be in linear gamma, sRGB, with premultiplied alpha.
 // You may not change it after calling finalize(), since that could change the
 // graph (need_linear_light() etc. depend on the border color you choose).
 //
-// As a convenience, if the flag “pad_from_bottom” is nonzero, the “top” parameter
-// will mean pixels from the bottom (matching OpenGL's usual bottom-left convention),
-// instead of from the top as usual.
+// IntegralPaddingEffect is like PaddingEffect, except that "top" and "left" parameters
+// are int parameters instead of float. This allows it to guarantee one-to-one sampling,
+// which can speed up processing by allowing more effect passes to be collapsed.
+// border_offset_* are still allowed to be float, although you should beware that if
+// you set e.g. border_offset_top to a negative value, you will be sampling outside
+// the edge and will read data that is undefined in one-to-one-mode (could be
+// edge repeat, could be something else). With regular PaddingEffect, such samples
+// are guaranteed to be edge repeat.
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <string>
 
 #include "effect.h"
@@ -26,24 +36,38 @@ namespace movit {
 class PaddingEffect : public Effect {
 public:
 	PaddingEffect();
-	virtual std::string effect_type_id() const { return "PaddingEffect"; }
-	std::string output_fragment_shader();
-	void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
+	std::string effect_type_id() const override { return "PaddingEffect"; }
+	std::string output_fragment_shader() override;
+	void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num) override;
 
-	virtual bool needs_linear_light() const;
-	virtual bool needs_srgb_primaries() const;
-	virtual AlphaHandling alpha_handling() const;
+	bool needs_linear_light() const override;
+	bool needs_srgb_primaries() const override;
+	AlphaHandling alpha_handling() const override;
 	
-	virtual bool changes_output_size() const { return true; }
-	virtual void get_output_size(unsigned *width, unsigned *height, unsigned *virtual_width, unsigned *virtual_height) const;
-	virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height);
+	bool changes_output_size() const override { return true; }
+	bool sets_virtual_output_size() const override { return false; }
+	void get_output_size(unsigned *width, unsigned *height, unsigned *virtual_width, unsigned *virtual_height) const override;
+	void inform_input_size(unsigned input_num, unsigned width, unsigned height) override;
 
 private:
 	RGBATuple border_color;
 	int input_width, input_height;
 	int output_width, output_height;
 	float top, left;
-	int pad_from_bottom;
+	float border_offset_top, border_offset_left;
+	float border_offset_bottom, border_offset_right;
+	float uniform_offset[2], uniform_scale[2];
+	float uniform_normalized_coords_to_texels[2];
+	float uniform_offset_bottomleft[2], uniform_offset_topright[2];
+};
+
+class IntegralPaddingEffect : public PaddingEffect {
+public:
+	IntegralPaddingEffect();
+	std::string effect_type_id() const override { return "IntegralPaddingEffect"; }
+	bool one_to_one_sampling() const override { return true; }
+	bool set_int(const std::string&, int value) override;
+	bool set_float(const std::string &key, float value) override;
 };
 
 }  // namespace movit