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# From the GLSL 4.40 spec, section 6.4 (Jumps):
#
# The continue jump is used only in loops. It skips the remainder
# of the body of the inner most loop of which it is inside. For
# while and do-while loops, this jump is to the next evaluation of
# the loop condition-expression from which the loop continues as
# previously defined.
#
# One way that do-while loops might be implemented is to convert them
# to infinite loops that terminate in a conditional break (this is
# what Mesa does). In such an implementation, an easy way to
# implement the proper behaviour of "continue" in a do-while loop is
# to replicate the conditional break at the site of the "continue".
# For example, this code:
#
# do {
# ...
# if (...) {
# ...
# continue;
# }
# ...
# } while (condition);
#
# would get translated to:
#
# loop {
# ...
# if (...) {
# ...
# if (!condition)
# break;
# continue;
# }
# ...
# if (!condition)
# break;
# }
#
# However, we must be careful in making this transformation if the
# "continue" occurs inside a switch statement, since "break" inside a
# switch statement normally exits the switch statement, not the
# surrounding loop.
#
# This test verifies that "continue" behaves properly when invoked
# inside a switch statement which is itself inside a do-while loop.
[require]
GLSL >= 1.30
[vertex shader]
#version 130
void main()
{
gl_Position = gl_Vertex;
int w = 0;
int x = 0;
int y = 0;
int z = 0;
do { // 1st iteration 2nd iteration
++w; // w <- 1 w <- 2
switch (w) { // Jump to case 1 Jump to case 2
case 1:
++x; // x <- 1
break; // Jump to ++z
case 2:
continue; // Jump to (w < 2)
case 3:
++y; // (this case is never executed)
break;
}
++z; // z <- 1 skipped
} while (w < 2); // true false
// The loop should execute for two iterations, so w should be 2. X
// should be incremented on the first iteration only, so it should
// be 1. Y should never be incremented (since w never reaches 3),
// so it should be 0. The "continue" should skip ++z on the second
// iteration, so z should be 1.
if (w == 2 && x == 1 && y == 0 && z == 1)
gl_FrontColor = vec4(0.0, 1.0, 0.0, 1.0);
else
gl_FrontColor = vec4(1.0, 0.0, 0.0, 1.0);
}
[fragment shader]
#version 130
void main()
{
gl_FragColor = gl_Color;
}
[test]
draw rect -1 -1 2 2
probe all rgba 0.0 1.0 0.0 1.0
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