X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=padding_effect.cpp;h=a70025d015475f885a9841d96e40c08fe3ac762e;hp=40876b89e9a6edca0cf2c89146894c1d72f15070;hb=7dca345804c7851ff09edcc7198c5def94b9c4b1;hpb=ad66f9714e4a36008c341355700272a52484a785

diff --git a/padding_effect.cpp b/padding_effect.cpp
index 40876b8..a70025d 100644
--- a/padding_effect.cpp
+++ b/padding_effect.cpp
@@ -5,33 +5,42 @@
 #include "padding_effect.h"
 #include "util.h"
 
+using namespace std;
+
+namespace movit {
+
 PaddingEffect::PaddingEffect()
 	: border_color(0.0f, 0.0f, 0.0f, 0.0f),
 	  output_width(1280),
 	  output_height(720),
 	  top(0),
-	  left(0)
+	  left(0),
+	  pad_from_bottom(0)
 {
 	register_vec4("border_color", (float *)&border_color);
 	register_int("width", &output_width);
 	register_int("height", &output_height);
 	register_float("top", &top);
 	register_float("left", &left);
+	register_int("pad_from_bottom", &pad_from_bottom);
 }
 
-std::string PaddingEffect::output_fragment_shader()
+string PaddingEffect::output_fragment_shader()
 {
 	return read_file("padding_effect.frag");
 }
 
-void PaddingEffect::set_gl_state(GLuint glsl_program_num, const std::string &prefix, unsigned *sampler_num)
+void PaddingEffect::set_gl_state(GLuint glsl_program_num, const string &prefix, unsigned *sampler_num)
 {
 	Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
 
-	float offset[2] = {
-		left / output_width,
-		(output_height - input_height - top) / output_height
-	};
+	float offset[2];
+	offset[0] = left / output_width;
+	if (pad_from_bottom) {
+		offset[1] = top / output_height;
+	} else {
+		offset[1] = (output_height - input_height - top) / output_height;
+	}
 	set_uniform_vec2(glsl_program_num, prefix, "offset", offset);
 
 	float scale[2] = {
@@ -64,12 +73,16 @@ void PaddingEffect::set_gl_state(GLuint glsl_program_num, const std::string &pre
 // differently in different modes.
 
 // 0.0 and 1.0 are interpreted the same, no matter the gamma ramp.
-// Alpha is not affected by gamma.
+// Alpha is not affected by gamma per se, but the combination of
+// premultiplied alpha and non-linear gamma curve does not make sense,
+// so if could possibly be converting blank alpha to non-blank
+// (ie., premultiplied), we need our output to be in linear light.
 bool PaddingEffect::needs_linear_light() const
 {
 	if ((border_color.r == 0.0 || border_color.r == 1.0) &&
 	    (border_color.g == 0.0 || border_color.g == 1.0) &&
-	    (border_color.b == 0.0 || border_color.b == 1.0)) {
+	    (border_color.b == 0.0 || border_color.b == 1.0) &&
+	    border_color.a == 1.0) {
 		return false;
 	}
 	return true;
@@ -124,3 +137,5 @@ void PaddingEffect::inform_input_size(unsigned input_num, unsigned width, unsign
 	input_width = width;
 	input_height = height;
 }
+
+}  // namespace movit