diff options
| -rw-r--r-- | tests/spec/ext_timer_query/time-elapsed.c | 57 |
1 files changed, 53 insertions, 4 deletions
diff --git a/tests/spec/ext_timer_query/time-elapsed.c b/tests/spec/ext_timer_query/time-elapsed.c index 8b93d890..942d7375 100644 --- a/tests/spec/ext_timer_query/time-elapsed.c +++ b/tests/spec/ext_timer_query/time-elapsed.c @@ -41,11 +41,51 @@ PIGLIT_GL_TEST_CONFIG_BEGIN PIGLIT_GL_TEST_CONFIG_END +static char *vs_text = + "#version 110\n" + "void main()\n" + "{\n" + " gl_Position = gl_Vertex;\n" + "}\n"; + +/** + * Time-wasting fragment shader. This fragment shader computes: + * + * x = (sum(i=0..(iters-1): 2*i) % iters) / iters + * + * This value should always work out to 0.0, but it's highly unlikely + * that an optimizer will figure this out. Hence we can use this + * shader to waste an arbitrary amount of time (by suitable choice of + * the value of iters). + * + * The shader outputs a color of (x, 1.0, 0.0, 0.0). + */ +static char *fs_text = + "#version 110\n" + "uniform int iters;\n" + "void main()\n" + "{\n" + " int cumulative_sum = 0;\n" + " for (int i = 0; i < iters; ++i) {\n" + " cumulative_sum += i;\n" + " if (cumulative_sum >= iters)\n" + " cumulative_sum -= iters;\n" + " cumulative_sum += i;\n" + " if (cumulative_sum >= iters)\n" + " cumulative_sum -= iters;\n" + " }\n" + " float x = float(cumulative_sum) / float(iters);\n" + " gl_FragColor = vec4(x, 1.0, 0.0, 0.0);\n" + "}\n"; + enum { TIME_ELAPSED, TIMESTAMP } test = TIME_ELAPSED; +GLuint prog; +GLint iters_loc; + static float get_time(void) { @@ -72,7 +112,9 @@ static float draw(GLuint *q, int iters) { float start_time, end_time; - int i; + + glUseProgram(prog); + glUniform1i(iters_loc, iters); start_time = get_time(); @@ -81,9 +123,7 @@ draw(GLuint *q, int iters) } else { glBeginQuery(GL_TIME_ELAPSED, q[0]); } - for (i = 0; i < iters; i++) { - piglit_draw_rect(-1, -1, 2, 2); - } + piglit_draw_rect(-1, -1, 2, 2); if (test == TIMESTAMP) { glQueryCounter(q[1], GL_TIMESTAMP); } else { @@ -270,8 +310,17 @@ retry: void piglit_init(int argc, char **argv) { + GLint vs, fs; + piglit_require_gl_version(20); + vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vs_text); + fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fs_text); + prog = piglit_link_simple_program(vs, fs); + glDeleteShader(vs); + glDeleteShader(fs); + iters_loc = glGetUniformLocation(prog, "iters"); + piglit_require_extension("GL_EXT_timer_query"); if (argc == 2 && strcmp(argv[1], "timestamp") == 0) { |