[Piglit] [PATCH 6/7] arb_vertex_attrib_binding: Test instance-divisor

[Eric Anholt]

Fredrik Höglund <fredrik at kde.org> writes:
> diff --git a/tests/spec/arb_vertex_attrib_binding/instance-divisor.c b/tests/spec/arb_vertex_attrib_binding/instance-divisor.c
> new file mode 100644
> index 0000000..88ae454
> --- /dev/null
> +++ b/tests/spec/arb_vertex_attrib_binding/instance-divisor.c

> +const char *vs_source =
> +	"attribute vec4 pos;\n"
> +	"attribute vec2 offset;\n"
> +	"attribute vec4 color;\n"
> +	"uniform vec2 global_offset;\n"
> +	"varying vec4 col;\n"
> +	"void main() {\n"
> +	"    col = color;\n"
> +	"    gl_Position = pos + vec4(global_offset + offset, vec2(0, 0));\n"
> +	"}";

> +enum piglit_result
> +piglit_display(void)
> +{
> +	const struct vec2 quad[] = {
> +		{ -0.125,  0.125 }, { 0.125,  0.125 },
> +		{ -0.125, -0.125 }, { 0.125, -0.125 }
> +	};
> +
> +	const struct vec2 offsets[] = {
> +		{ -.75, 0 }, { -.25, 0 }, { .25, 0 }, { .75, 0 }
> +	};
> +
> +	const struct vec4 colors[] = {
> +		{ 1.0, 0.0, 0.0, 1.0 },
> +		{ 0.0, 1.0, 0.0, 1.0 },
> +		{ 0.0, 0.0, 1.0, 1.0 },
> +		{ 1.0, 1.0, 1.0, 1.0 }
> +	};
> +
> +	GLuint vbo1, vbo2, vbo3, vao;
> +	bool pass = true;
> +
> +	glGenVertexArrays(1, &vao);
> +	glBindVertexArray(vao);
> +
> +	glGenBuffers(1, &vbo1);
> +	glGenBuffers(1, &vbo2);
> +	glGenBuffers(1, &vbo3);
> +
> +	glBindBuffer(GL_ARRAY_BUFFER, vbo1);
> +	glBufferData(GL_ARRAY_BUFFER, sizeof(quad), (const GLvoid *) quad, GL_STATIC_DRAW);
> +
> +	glBindBuffer(GL_ARRAY_BUFFER, vbo2);
> +	glBufferData(GL_ARRAY_BUFFER, sizeof(offsets), (const GLvoid *) offsets, GL_STATIC_DRAW);

I'm confused why there's both pos/quad (with two names) and offset.
Could you just have a single pre-baked pos vec2?

> +	pass = piglit_probe_pixel_rgba(piglit_width * .125, piglit_height * .75, (const float *) &colors[0]);
> +	pass = piglit_probe_pixel_rgba(piglit_width * .375, piglit_height * .75, (const float *) &colors[1]);
> +	pass = piglit_probe_pixel_rgba(piglit_width * .625, piglit_height * .75, (const float *) &colors[2]);
> +	pass = piglit_probe_pixel_rgba(piglit_width * .875, piglit_height * .75, (const float *) &colors[3]);
> +
> +	pass = piglit_probe_pixel_rgba(piglit_width * .125, piglit_height * .25, (const float *) &colors[0]);
> +	pass = piglit_probe_pixel_rgba(piglit_width * .375, piglit_height * .25, (const float *) &colors[0]);
> +	pass = piglit_probe_pixel_rgba(piglit_width * .625, piglit_height * .25, (const float *) &colors[1]);
> +	pass = piglit_probe_pixel_rgba(piglit_width * .875, piglit_height * .25, (const float *) &colors[1]);

Again, not required, but I like probe_rect (when the HW craps out and
only draws some of the pixels, you get fewer false positives).

> +void
> +piglit_init(int argc, char **argv)
> +{
> +	GLuint vs, fs;
> +
> +	piglit_require_extension("GL_ARB_vertex_attrib_binding");

Since I think we're enabling this extension on all Mesa drivers
regardless of HW support for instancing, I think this should also depend
on GL_ARB_instanced_arrays.  (It's not called out in the spec because
they wrote it against 4.2).

> +	vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vs_source);
> +	fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fs_source);
> +	program = piglit_link_simple_program(vs, fs);

piglit_build_simple_program().

> +	pos           = glGetAttribLocation(program, "pos");
> +	offset        = glGetAttribLocation(program, "offset");
> +	color         = glGetAttribLocation(program, "color");
> +	global_offset = glGetUniformLocation(program, "global_offset");
> +}
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 835 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/piglit/attachments/20131030/5fcb4e11/attachment-0001.pgp>