output_width(1280),
output_height(720),
top(0),
- left(0)
+ left(0),
+ border_offset_top(0.0f),
+ border_offset_left(0.0f),
+ border_offset_bottom(0.0f),
+ border_offset_right(0.0f)
{
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_float("border_offset_top", &border_offset_top);
+ register_float("border_offset_left", &border_offset_left);
+ register_float("border_offset_bottom", &border_offset_bottom);
+ register_float("border_offset_right", &border_offset_right);
+ register_uniform_vec2("offset", uniform_offset);
+ register_uniform_vec2("scale", uniform_scale);
+ register_uniform_vec2("normalized_coords_to_texels", uniform_normalized_coords_to_texels);
+ register_uniform_vec2("offset_bottomleft", uniform_offset_bottomleft);
+ register_uniform_vec2("offset_topright", uniform_offset_topright);
}
string PaddingEffect::output_fragment_shader()
{
Effect::set_gl_state(glsl_program_num, prefix, sampler_num);
- float offset[2] = {
- left / output_width,
- (output_height - input_height - top) / output_height
- };
- set_uniform_vec2(glsl_program_num, prefix, "offset", offset);
-
- float scale[2] = {
- float(output_width) / input_width,
- float(output_height) / input_height
- };
- set_uniform_vec2(glsl_program_num, prefix, "scale", scale);
-
- // Due to roundoff errors, the test against 0.5 is seldom exact,
- // even though we test for less than and not less-than-or-equal.
- // We'd rather keep an extra border pixel in those very rare cases
- // (where the image is shifted pretty much exactly a half-pixel)
- // than losing a pixel in the common cases of integer shift.
- // Thus the 1e-3 fudge factors.
- float texcoord_min[2] = {
- float((0.5f - 1e-3) / input_width),
- float((0.5f - 1e-3) / input_height)
- };
- set_uniform_vec2(glsl_program_num, prefix, "texcoord_min", texcoord_min);
-
- float texcoord_max[2] = {
- float(1.0f - (0.5f - 1e-3) / input_width),
- float(1.0f - (0.5f - 1e-3) / input_height)
- };
- set_uniform_vec2(glsl_program_num, prefix, "texcoord_max", texcoord_max);
+ uniform_offset[0] = left / output_width;
+ uniform_offset[1] = (output_height - input_height - top) / output_height;
+
+ uniform_scale[0] = float(output_width) / input_width;
+ uniform_scale[1] = float(output_height) / input_height;
+
+ uniform_normalized_coords_to_texels[0] = float(input_width);
+ uniform_normalized_coords_to_texels[1] = float(input_height);
+
+ // Texels -0.5..0.5 should map to light level 0..1 (and then we
+ // clamp the rest).
+ uniform_offset_bottomleft[0] = 0.5f - border_offset_left;
+ uniform_offset_bottomleft[1] = 0.5f + border_offset_bottom;
+
+ // Texels size-0.5..size+0.5 should map to light level 1..0 (and then clamp).
+ uniform_offset_topright[0] = input_width + 0.5f + border_offset_right;
+ uniform_offset_topright[1] = input_height + 0.5f - border_offset_top;
}
// We don't change the pixels of the image itself, so the only thing that
Effect::AlphaHandling PaddingEffect::alpha_handling() const
{
- // If the border color is black, it doesn't matter if we're pre- or postmultiplied.
- // Note that for non-solid black (i.e. alpha < 1.0), we're equally fine with
- // pre- and postmultiplied, but later effects might change this status
- // (consider e.g. blur), so setting DONT_CARE_ALPHA_TYPE is inappropriate,
- // as it propagate blank alpha through this effect.
- if (border_color.r == 0.0 && border_color.g == 0.0 && border_color.b == 0.0 && border_color.a == 1.0) {
- return DONT_CARE_ALPHA_TYPE;
- }
-
- // If the border color is solid, we preserve blank alpha, as we never output any
- // new non-solid pixels.
+ // If the border color is solid, it doesn't matter if we're pre- or postmultiplied.
if (border_color.a == 1.0) {
- return INPUT_PREMULTIPLIED_ALPHA_KEEP_BLANK;
+ return DONT_CARE_ALPHA_TYPE;
}
// Otherwise, we're going to output our border color in premultiplied alpha,
// so the other pixels better be premultiplied as well.
+ // Note that for non-solid black (i.e. alpha < 1.0), we're equally fine with
+ // pre- and postmultiplied, but we are _not_ fine with blank being passed through,
+ // and we don't have a way to specify that.
return INPUT_AND_OUTPUT_PREMULTIPLIED_ALPHA;
}
input_height = height;
}
+IntegralPaddingEffect::IntegralPaddingEffect() {}
+
+bool IntegralPaddingEffect::set_int(const std::string &key, int value)
+{
+ if (key == "top" || key == "left") {
+ return PaddingEffect::set_float(key, value);
+ } else {
+ return PaddingEffect::set_int(key, value);
+ }
+}
+
+bool IntegralPaddingEffect::set_float(const std::string &key, float value)
+{
+ if (key == "top" || key == "left") {
+ // These are removed as float parameters from this version.
+ return false;
+ } else {
+ return PaddingEffect::set_float(key, value);
+ }
+}
+
} // namespace movit
projects / movit / blobdiff