[tests] Adds an interactive cogl vertex buffer unit test

The test is a sanity check that dynamic updating of vertex data via the cogl
vertex buffer api works and has reasonable performance. (though it can't be
considered a well designed benchmark since it wastes casual amounts of CPU
time simply choosing pretty colors.)

The code also aims to demonstrate one way of creating, updating and efficiently
drawing a quad mesh structure via the vertex buffer api which could be applied
to lots of different use cases.
This commit is contained in:
Robert Bragg 2009-03-16 12:47:45 +00:00
parent 71d65b629b
commit c5bd63648d
2 changed files with 430 additions and 1 deletions

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@ -42,7 +42,8 @@ UNIT_TESTS = \
test-binding-pool.c \ test-binding-pool.c \
test-text.c \ test-text.c \
test-text-field.c \ test-text-field.c \
test-clutter-cairo-flowers.c test-clutter-cairo-flowers.c \
test-cogl-vertex-buffer.c
if X11_TESTS if X11_TESTS
UNIT_TESTS += test-pixmap.c UNIT_TESTS += test-pixmap.c

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@ -0,0 +1,428 @@
#include <config.h>
#include <glib.h>
#include <gmodule.h>
#include <stdlib.h>
#include <clutter/clutter.h>
#include <cogl/cogl.h>
#include <math.h>
/* Defines the size and resolution of the quad mesh we morph:
*/
#define MESH_WIDTH 100.0 /* number of quads along x axis */
#define MESH_HEIGHT 100.0 /* number of quads along y axis */
#define QUAD_WIDTH 5.0 /* width in pixels of a single quad */
#define QUAD_HEIGHT 5.0 /* height in pixels of a single quad */
/* Defines a sine wave that sweeps across the mesh:
*/
#define WAVE_DEPTH ((MESH_WIDTH * QUAD_WIDTH) / 16.0) /* peak amplitude */
#define WAVE_PERIODS 4.0
#define WAVE_SPEED 10.0
/* Defines a rippling sine wave emitted from a point:
*/
#define RIPPLE_CENTER_X ((MESH_WIDTH / 2.0) * QUAD_WIDTH)
#define RIPPLE_CENTER_Y ((MESH_HEIGHT / 2.0) * QUAD_HEIGHT)
#define RIPPLE_RADIUS (MESH_WIDTH * QUAD_WIDTH)
#define RIPPLE_DEPTH ((MESH_WIDTH * QUAD_WIDTH) / 16.0) /* peak amplitude */
#define RIPPLE_PERIODS 4.0
#define RIPPLE_SPEED -10.0
/* Defines the width of the gaussian bell used to fade out the alpha
* towards the edges of the mesh (starting from the ripple center):
*/
#define GAUSSIAN_RADIUS ((MESH_WIDTH * QUAD_WIDTH) / 6.0)
/* Our hues lie in the range [0, 1], and this defines how we map amplitude
* to hues (before scaling by {WAVE,RIPPLE}_DEPTH)
* As we are interferring two sine waves together; amplitudes lie in the
* range [-2, 2]
*/
#define HSL_OFFSET 0.5 /* the hue that we map an amplitude of 0 too */
#define HSL_SCALE 0.25
typedef struct _TestState
{
ClutterActor *dummy;
CoglHandle buffer;
float *quad_mesh_verts;
GLubyte *quad_mesh_colors;
GLushort *static_indices;
guint n_static_indices;
ClutterTimeline *timeline;
} TestState;
/* This algorithm is adapted from the book:
* Fundamentals of Interactive Computer Graphics by Foley and van Dam
*/
static void
hsl_to_rgb (float h, float s, float l,
GLubyte *r, GLubyte *g, GLubyte *b)
{
float tmp1, tmp2;
float tmp3[3];
float clr[3];
int i;
if (l == 0)
{
*r = *g = *b = 0;
return;
}
if (s == 0)
{
*r = *g = *b = l;
return;
}
tmp2 = ((l <= 0.5) ? l * (1.0 + s) : l + s - (l * s));
tmp1 = 2.0 * l - tmp2;
tmp3[0] = h + 1.0 / 3.0;
tmp3[1] = h;
tmp3[2] = h - 1.0 / 3.0;
for (i = 0; i < 3; i++)
{
if (tmp3[i] < 0)
tmp3[i] += 1.0;
if (tmp3[i] > 1)
tmp3[i] -= 1.0;
if (6.0 * tmp3[i] < 1.0)
clr[i] = tmp1 + (tmp2 - tmp1) * tmp3[i] * 6.0;
else if (2.0 * tmp3[i] < 1.0)
clr[i] = tmp2;
else if (3.0 * tmp3[i] < 2.0)
clr[i] = (tmp1 + (tmp2 - tmp1) * ((2.0 / 3.0) - tmp3[i]) * 6.0);
else
clr[i] = tmp1;
}
*r = clr[0] * 255.0;
*g = clr[1] * 255.0;
*b = clr[2] * 255.0;
}
static void
frame_cb (ClutterTimeline *timeline,
gint frame_num,
TestState *state)
{
guint x, y;
guint n_frames = clutter_timeline_get_n_frames (timeline);
float period_progress = ((float)frame_num / (float)n_frames) * 2.0 * G_PI;
float period_progress_sin = sinf (period_progress);
float wave_shift = period_progress * WAVE_SPEED;
float ripple_shift = period_progress * RIPPLE_SPEED;
for (y = 0; y <= MESH_HEIGHT; y++)
for (x = 0; x <= MESH_WIDTH; x++)
{
guint vert_index = (MESH_WIDTH + 1) * y + x;
float *vert = &state->quad_mesh_verts[3 * vert_index];
float real_x = x * QUAD_WIDTH;
float real_y = y * QUAD_HEIGHT;
float wave_offset = (float)x / (MESH_WIDTH + 1);
float wave_angle =
(WAVE_PERIODS * 2 * G_PI * wave_offset) + wave_shift;
float wave_sin = sinf (wave_angle);
float a_sqr = (RIPPLE_CENTER_X - real_x) * (RIPPLE_CENTER_X - real_x);
float b_sqr = (RIPPLE_CENTER_Y - real_y) * (RIPPLE_CENTER_Y - real_y);
float ripple_offset = sqrtf (a_sqr + b_sqr) / RIPPLE_RADIUS;
float ripple_angle =
(RIPPLE_PERIODS * 2 * G_PI * ripple_offset) + ripple_shift;
float ripple_sin = sinf (ripple_angle);
float h, s, l;
GLubyte *color;
vert[2] = (wave_sin * WAVE_DEPTH) + (ripple_sin * RIPPLE_DEPTH);
/* Burn some CPU time picking a pretty color... */
h = (HSL_OFFSET
+ wave_sin
+ ripple_sin
+ period_progress_sin) * HSL_SCALE;
s = 0.5;
l = 0.25 + (period_progress_sin + 1.0) / 4.0;
color = &state->quad_mesh_colors[4 * vert_index];
hsl_to_rgb (h, s, l, &color[0], &color[1], &color[2]);
}
cogl_vertex_buffer_add (state->buffer,
"gl_Vertex",
3, /* n components */
GL_FLOAT,
FALSE, /* normalized */
0, /* stride */
state->quad_mesh_verts);
cogl_vertex_buffer_add (state->buffer,
"gl_Color",
4, /* n components */
GL_UNSIGNED_BYTE,
FALSE, /* normalized */
0, /* stride */
state->quad_mesh_colors);
cogl_vertex_buffer_submit (state->buffer);
clutter_actor_set_rotation (state->dummy,
CLUTTER_Z_AXIS,
frame_num,
(MESH_WIDTH * QUAD_WIDTH) / 2,
(MESH_HEIGHT * QUAD_HEIGHT) / 2,
0);
clutter_actor_set_rotation (state->dummy,
CLUTTER_X_AXIS,
frame_num,
(MESH_WIDTH * QUAD_WIDTH) / 2,
(MESH_HEIGHT * QUAD_HEIGHT) / 2,
0);
}
static void
on_paint (ClutterActor *actor, TestState *state)
{
cogl_set_source_color4ub (0xff, 0x00, 0x00, 0xff);
cogl_vertex_buffer_draw_elements (state->buffer,
GL_TRIANGLE_STRIP,
0,
(MESH_WIDTH + 1) * (MESH_HEIGHT + 1),
state->n_static_indices,
GL_UNSIGNED_SHORT,
state->static_indices);
}
static void
init_static_index_arrays (TestState *state)
{
guint n_indices;
int x, y;
GLushort *i;
guint dir;
/* - Each row takes (2 + 2 * MESH_WIDTH indices)
* - Thats 2 to start the triangle strip then 2 indices to add 2 triangles
* per mesh quad.
* - We have MESH_HEIGHT rows
* - It takes one extra index for linking between rows (MESH_HEIGHT - 1)
* - A 2 x 3 mesh == 20 indices... */
n_indices = (2 + 2 * MESH_WIDTH) * MESH_HEIGHT + (MESH_HEIGHT - 1);
state->static_indices = g_malloc (sizeof (GLushort) * n_indices);
state->n_static_indices = n_indices;
#define MESH_INDEX(X, Y) (Y) * (MESH_WIDTH + 1) + (X)
i = state->static_indices;
/* NB: front facing == anti-clockwise winding */
i[0] = MESH_INDEX (0, 0);
i[1] = MESH_INDEX (0, 1);
i += 2;
#define LEFT 0
#define RIGHT 1
dir = RIGHT;
for (y = 0; y < MESH_HEIGHT; y++)
{
for (x = 0; x < MESH_WIDTH; x++)
{
/* Add 2 triangles per mesh quad... */
if (dir == RIGHT)
{
i[0] = MESH_INDEX (x + 1, y);
i[1] = MESH_INDEX (x + 1, y + 1);
}
else
{
i[0] = MESH_INDEX (MESH_WIDTH - x - 1, y);
i[1] = MESH_INDEX (MESH_WIDTH - x - 1, y + 1);
}
i += 2;
}
/* Link rows... */
if (y == (MESH_HEIGHT - 1))
break;
if (dir == RIGHT)
{
i[0] = MESH_INDEX (MESH_WIDTH, y + 1);
i[1] = MESH_INDEX (MESH_WIDTH, y + 1);
i[2] = MESH_INDEX (MESH_WIDTH, y + 2);
}
else
{
i[0] = MESH_INDEX (0, y + 1);
i[1] = MESH_INDEX (0, y + 1);
i[2] = MESH_INDEX (0, y + 2);
}
i += 3;
dir = !dir;
}
#undef MESH_INDEX
}
static float
gaussian (float x, float y)
{
/* Bell width */
float c = GAUSSIAN_RADIUS;
/* Peak amplitude */
float a = 1.0;
/* float a = 1.0 / (c * sqrtf (2.0 * G_PI)); */
/* Center offset */
float b = 0.0;
x = x - RIPPLE_CENTER_X;
y = y - RIPPLE_CENTER_Y;
float dist = sqrtf (x*x + y*y);
return a * exp ((- ((dist - b) * (dist - b))) / (2.0 * c * c));
}
static void
init_quad_mesh (TestState *state)
{
int x, y;
float *vert;
GLubyte *color;
/* Note: we maintain the minimum number of vertices possible. This minimizes
* the work required when we come to morph the geometry.
*
* We use static indices into our mesh so that we can treat the data like a
* single triangle list and drawing can be done in one operation (Note: We
* are using degenerate triangles at the edges to link to the next row)
*/
state->quad_mesh_verts =
g_malloc0 (sizeof (float) * 3 * (MESH_WIDTH + 1) * (MESH_HEIGHT + 1));
state->quad_mesh_colors =
g_malloc0 (sizeof (GLubyte) * 4 * (MESH_WIDTH + 1) * (MESH_HEIGHT + 1));
vert = state->quad_mesh_verts;
color = state->quad_mesh_colors;
for (y = 0; y <= MESH_HEIGHT; y++)
for (x = 0; x <= MESH_WIDTH; x++)
{
vert[0] = x * QUAD_WIDTH;
vert[1] = y * QUAD_HEIGHT;
vert += 3;
color[3] = gaussian (x * QUAD_WIDTH,
y * QUAD_HEIGHT) * 255.0;
color += 4;
}
state->buffer = cogl_vertex_buffer_new ((MESH_WIDTH + 1)*(MESH_HEIGHT + 1));
cogl_vertex_buffer_add (state->buffer,
"gl_Vertex",
3, /* n components */
GL_FLOAT,
FALSE, /* normalized */
0, /* stride */
state->quad_mesh_verts);
cogl_vertex_buffer_add (state->buffer,
"gl_Color",
4, /* n components */
GL_UNSIGNED_BYTE,
FALSE, /* normalized */
0, /* stride */
state->quad_mesh_colors);
cogl_vertex_buffer_submit (state->buffer);
init_static_index_arrays (state);
}
/* This creates an actor that has a specific size but that does not result
* in any drawing so we can do our own drawing using Cogl... */
static ClutterActor *
create_dummy_actor (guint width, guint height)
{
ClutterActor *group, *rect;
ClutterColor clr = { 0xff, 0xff, 0xff, 0xff};
group = clutter_group_new ();
rect = clutter_rectangle_new_with_color (&clr);
clutter_actor_set_size (rect, width, height);
clutter_actor_hide (rect);
clutter_container_add_actor (CLUTTER_CONTAINER (group), rect);
return group;
}
static gboolean
queue_redraw (gpointer stage)
{
clutter_actor_queue_redraw (CLUTTER_ACTOR (stage));
return TRUE;
}
G_MODULE_EXPORT int
test_cogl_vertex_buffer_main (int argc, char *argv[])
{
TestState state;
ClutterActor *stage;
ClutterColor stage_clr = {0x0, 0x0, 0x0, 0xff};
ClutterGeometry stage_geom;
gint dummy_width, dummy_height;
guint idle_source;
clutter_init (&argc, &argv);
stage = clutter_stage_get_default ();
clutter_stage_set_color (CLUTTER_STAGE (stage), &stage_clr);
clutter_actor_get_geometry (stage, &stage_geom);
dummy_width = MESH_WIDTH * QUAD_WIDTH;
dummy_height = MESH_HEIGHT * QUAD_HEIGHT;
state.dummy = create_dummy_actor (dummy_width, dummy_height);
clutter_container_add_actor (CLUTTER_CONTAINER (stage), state.dummy);
clutter_actor_set_position (state.dummy,
(stage_geom.width / 2.0) - (dummy_width / 2.0),
(stage_geom.height / 2.0) - (dummy_height / 2.0));
state.timeline = clutter_timeline_new (360, 60);
clutter_timeline_set_loop (state.timeline, TRUE);
g_signal_connect (state.timeline,
"new-frame",
G_CALLBACK (frame_cb),
&state);
/* We want continuous redrawing of the stage... */
idle_source = g_idle_add (queue_redraw, stage);
g_signal_connect (state.dummy, "paint", G_CALLBACK (on_paint), &state);
init_quad_mesh (&state);
clutter_actor_show_all (stage);
clutter_timeline_start (state.timeline);
clutter_main ();
cogl_vertex_buffer_unref (state.buffer);
g_source_remove (idle_source);
return 0;
}