1 #ifndef _MOVIT_PADDING_EFFECT_H
2 #define _MOVIT_PADDING_EFFECT_H 1
4 // Takes an image and pads it to fit a larger image, or crops it to fit a smaller one
5 // (although the latter is implemented slightly less efficiently, and you cannot both
6 // pad and crop in the same effect).
8 // The source image is cut off at the texture border, and then given a user-specific color;
9 // by default, full transparent. You can give a fractional border size (non-integral
10 // "top" or "left" offset) if you wish, which will give you linear interpolation of
11 // both pixel data of and the border. Furthermore, you can offset where the border falls
12 // by using the "border_offset_{top,bottom,left,right}" settings; this is particularly
13 // useful if you use ResampleEffect earlier in the chain for high-quality fractional-pixel
14 // translation and just want PaddingEffect to get the border right.
16 // The border color is taken to be in linear gamma, sRGB, with premultiplied alpha.
17 // You may not change it after calling finalize(), since that could change the
18 // graph (need_linear_light() etc. depend on the border color you choose).
20 // IntegralPaddingEffect is like PaddingEffect, except that "top" and "left" parameters
21 // are int parameters instead of float. This allows it to guarantee one-to-one sampling,
22 // which can speed up processing by allowing more effect passes to be collapsed.
23 // border_offset_* are still allowed to be float, although you should beware that if
24 // you set e.g. border_offset_top to a negative value, you will be sampling outside
25 // the edge and will read data that is undefined in one-to-one-mode (could be
26 // edge repeat, could be something else). With regular PaddingEffect, such samples
27 // are guaranteed to be edge repeat.
36 class PaddingEffect : public Effect {
39 virtual std::string effect_type_id() const { return "PaddingEffect"; }
40 std::string output_fragment_shader();
41 void set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num);
43 virtual bool needs_linear_light() const;
44 virtual bool needs_srgb_primaries() const;
45 virtual AlphaHandling alpha_handling() const;
47 virtual bool changes_output_size() const { return true; }
48 virtual bool sets_virtual_output_size() const { return false; }
49 virtual void get_output_size(unsigned *width, unsigned *height, unsigned *virtual_width, unsigned *virtual_height) const;
50 virtual void inform_input_size(unsigned input_num, unsigned width, unsigned height);
53 RGBATuple border_color;
54 int input_width, input_height;
55 int output_width, output_height;
57 float border_offset_top, border_offset_left;
58 float border_offset_bottom, border_offset_right;
59 float uniform_offset[2], uniform_scale[2];
60 float uniform_normalized_coords_to_texels[2];
61 float uniform_offset_bottomleft[2], uniform_offset_topright[2];
64 class IntegralPaddingEffect : public PaddingEffect {
66 IntegralPaddingEffect();
67 virtual std::string effect_type_id() const { return "IntegralPaddingEffect"; }
68 virtual bool one_to_one_sampling() const { return true; }
69 virtual bool set_int(const std::string&, int value);
70 virtual bool set_float(const std::string &key, float value);
75 #endif // !defined(_MOVIT_PADDING_EFFECT_H)