Adds another example that draws a 3D crate

Based on the Cogl example we had on wiki.clutter-project.org this shows
how to use the primitive API to draw a simple spinning crate.

Signed-off-by: Neil Roberts <neil@linux.intel.com>
This commit is contained in:
Robert Bragg 2011-05-11 16:37:09 +01:00
parent a1234ee8d1
commit 716b88b0c8
3 changed files with 285 additions and 1 deletions

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@ -8,7 +8,8 @@ INCLUDES = \
AM_CFLAGS = \ AM_CFLAGS = \
$(COGL_DEP_CFLAGS) \ $(COGL_DEP_CFLAGS) \
$(COGL_EXTRA_CFLAGS) \ $(COGL_EXTRA_CFLAGS) \
-DCOGL_ENABLE_EXPERIMENTAL_2_0_API -DCOGL_ENABLE_EXPERIMENTAL_2_0_API \
-DCOGL_EXAMPLES_DATA=\""$(abs_top_srcdir)/examples/"\"
AM_CPPFLAGS = \ AM_CPPFLAGS = \
-DG_DISABLE_SINGLE_INCLUDES \ -DG_DISABLE_SINGLE_INCLUDES \
@ -24,6 +25,12 @@ noinst_PROGRAMS = hello
hello_SOURCES = hello.c hello_SOURCES = hello.c
hello_LDADD = $(common_ldadd) hello_LDADD = $(common_ldadd)
if BUILD_COGL_PANGO
noinst_PROGRAMS += crate
crate_SOURCES = crate.c
crate_LDADD = $(common_ldadd) $(top_builddir)/cogl-pango/libcogl-pango.la
endif
if X11_TESTS if X11_TESTS
noinst_PROGRAMS += x11-foreign noinst_PROGRAMS += x11-foreign
x11_foreign_SOURCES = x11-foreign.c x11_foreign_SOURCES = x11-foreign.c
@ -35,3 +42,5 @@ noinst_PROGRAMS += cogland
cogland_SOURCES = cogland.c cogland_SOURCES = cogland.c
cogland_LDADD = $(common_ldadd) cogland_LDADD = $(common_ldadd)
endif endif
EXTRA_DIST = crate.jpg

275
examples/crate.c Normal file
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@ -0,0 +1,275 @@
#include <cogl/cogl.h>
#include <cogl-pango/cogl-pango.h>
/* The state for this example... */
typedef struct _Data
{
int framebuffer_width;
int framebuffer_height;
CoglMatrix view;
CoglPrimitive *prim;
CoglHandle texture;
CoglPipeline *crate_pipeline;
/* The cube continually rotates around each axis. */
float rotate_x;
float rotate_y;
float rotate_z;
CoglPangoFontMap *pango_font_map;
PangoContext *pango_context;
PangoFontDescription *pango_font_desc;
PangoLayout *hello_label;
int hello_label_width;
int hello_label_height;
} Data;
/* A static identity matrix initialized for convenience. */
static CoglMatrix identity;
/* static colors initialized for convenience. */
static CoglColor black;
static CoglColor white;
/* A cube modelled as a list of triangles. Potentially this could be
* done more efficiently as a triangle strip or using a separate index
* array, but this way is pretty simple, if a little verbose. */
CoglVertexP3T2 vertices[] =
{
/* Front face */
{ /* pos = */ -1.0f, -1.0f, 1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, 1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ 1.0f, 1.0f, 1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ -1.0f, -1.0f, 1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, 1.0f, 1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ -1.0f, 1.0f, 1.0f, /* tex coords = */ 0.0f, 0.0f},
/* Back face */
{ /* pos = */ -1.0f, -1.0f, -1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ -1.0f, 1.0f, -1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ 1.0f, 1.0f, -1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ -1.0f, -1.0f, -1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ 1.0f, 1.0f, -1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, -1.0f, /* tex coords = */ 0.0f, 0.0f},
/* Top face */
{ /* pos = */ -1.0f, 1.0f, -1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ -1.0f, 1.0f, 1.0f, /* tex coords = */ 0.0f, 0.0f},
{ /* pos = */ 1.0f, 1.0f, 1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ -1.0f, 1.0f, -1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, 1.0f, 1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ 1.0f, 1.0f, -1.0f, /* tex coords = */ 1.0f, 1.0f},
/* Bottom face */
{ /* pos = */ -1.0f, -1.0f, -1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, -1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, 1.0f, /* tex coords = */ 0.0f, 0.0f},
{ /* pos = */ -1.0f, -1.0f, -1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, 1.0f, /* tex coords = */ 0.0f, 0.0f},
{ /* pos = */ -1.0f, -1.0f, 1.0f, /* tex coords = */ 1.0f, 0.0f},
/* Right face */
{ /* pos = */ 1.0f, -1.0f, -1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ 1.0f, 1.0f, -1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ 1.0f, 1.0f, 1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, -1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ 1.0f, 1.0f, 1.0f, /* tex coords = */ 0.0f, 1.0f},
{ /* pos = */ 1.0f, -1.0f, 1.0f, /* tex coords = */ 0.0f, 0.0f},
/* Left face */
{ /* pos = */ -1.0f, -1.0f, -1.0f, /* tex coords = */ 0.0f, 0.0f},
{ /* pos = */ -1.0f, -1.0f, 1.0f, /* tex coords = */ 1.0f, 0.0f},
{ /* pos = */ -1.0f, 1.0f, 1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ -1.0f, -1.0f, -1.0f, /* tex coords = */ 0.0f, 0.0f},
{ /* pos = */ -1.0f, 1.0f, 1.0f, /* tex coords = */ 1.0f, 1.0f},
{ /* pos = */ -1.0f, 1.0f, -1.0f, /* tex coords = */ 0.0f, 1.0f}
};
static void
paint (Data *data)
{
cogl_clear (&black, COGL_BUFFER_BIT_COLOR|COGL_BUFFER_BIT_DEPTH);
cogl_push_matrix ();
cogl_translate (data->framebuffer_width / 2, data->framebuffer_height / 2, 0);
cogl_scale (75, 75, 75);
/* Rotate the cube separately around each axis.
*
* Note: Cogl matrix manipulation follows the same rules as for
* OpenGL. We use column-major matrices and - if you consider the
* transformations happening to the model - then they are combined
* in reverse order which is why the rotation is done last, since
* we want it to be a rotation around the origin, before it is
* scaled and translated.
*/
cogl_rotate (data->rotate_x++, 0, 0, 1);
cogl_rotate (data->rotate_y++, 0, 1, 0);
cogl_rotate (data->rotate_z++, 1, 0, 0);
/* Whenever you draw something with Cogl using geometry defined by
* one of cogl_rectangle, cogl_polygon, cogl_path or
* cogl_vertex_buffer then you have a current pipeline that defines
* how that geometry should be processed.
*
* Here we are making our crate pipeline current which will sample
* the crate texture when fragment processing. */
cogl_set_source (data->crate_pipeline);
/* Give Cogl some geometry to draw. */
cogl_primitive_draw (data->prim);
cogl_set_depth_test_enabled (FALSE);
cogl_pop_matrix ();
/* And finally render our Pango layouts... */
cogl_pango_render_layout (data->hello_label,
(data->framebuffer_width / 2) -
(data->hello_label_width / 2),
(data->framebuffer_height / 2) -
(data->hello_label_height / 2),
&white, 0);
}
int
main (int argc, char **argv)
{
CoglContext *ctx;
CoglOnscreen *onscreen;
CoglFramebuffer *fb;
GError *error = NULL;
Data data;
PangoRectangle hello_label_size;
float fovy, aspect, z_near, z_2d, z_far;
CoglDepthState depth_state;
g_type_init ();
ctx = cogl_context_new (NULL, &error);
if (!ctx) {
fprintf (stderr, "Failed to create context: %s\n", error->message);
return 1;
}
data.framebuffer_width = 640;
data.framebuffer_height = 480;
onscreen = cogl_onscreen_new (ctx, data.framebuffer_width, data.framebuffer_height);
/* Eventually there will be an implicit allocate on first use so this
* will become optional... */
fb = COGL_FRAMEBUFFER (onscreen);
if (!cogl_framebuffer_allocate (fb, &error)) {
fprintf (stderr, "Failed to allocate framebuffer: %s\n", error->message);
return 1;
}
cogl_onscreen_show (onscreen);
cogl_push_framebuffer (fb);
cogl_set_viewport (0, 0, data.framebuffer_width, data.framebuffer_height);
fovy = 60; /* y-axis field of view */
aspect = (float)data.framebuffer_width/(float)data.framebuffer_height;
z_near = 0.1; /* distance to near clipping plane */
z_2d = 1000; /* position to 2d plane */
z_far = 2000; /* distance to far clipping plane */
cogl_perspective (fovy, aspect, z_near, z_far);
/* Since the pango renderer emits geometry in pixel/device coordinates
* and the anti aliasing is implemented with the assumption that the
* geometry *really* does end up pixel aligned, we setup a modelview
* matrix so that for geometry in the plane z = 0 we exactly map x
* coordinates in the range [0,stage_width] and y coordinates in the
* range [0,stage_height] to the framebuffer extents with (0,0) being
* the top left.
*
* This is roughly what Clutter does for a ClutterStage, but this
* demonstrates how it is done manually using Cogl.
*/
cogl_matrix_init_identity (&data.view);
cogl_matrix_view_2d_in_perspective (&data.view, fovy, aspect, z_near, z_2d,
data.framebuffer_width,
data.framebuffer_height);
cogl_set_modelview_matrix (&data.view);
cogl_pop_framebuffer ();
/* Initialize some convenient constants */
cogl_matrix_init_identity (&identity);
cogl_color_set_from_4ub (&black, 0x00, 0x00, 0x00, 0xff);
cogl_color_set_from_4ub (&white, 0xff, 0xff, 0xff, 0xff);
data.prim = cogl_primitive_new_p3t2 (COGL_VERTICES_MODE_TRIANGLES,
G_N_ELEMENTS (vertices),
vertices);
/* Load a jpeg crate texture from a file */
printf ("crate.jpg (CC by-nc-nd http://bit.ly/9kP45T) ShadowRunner27 http://bit.ly/m1YXLh\n");
data.texture = cogl_texture_new_from_file (COGL_EXAMPLES_DATA "crate.jpg",
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_ANY,
NULL);
if (!data.texture)
g_error ("Failed to load texture");
/* a CoglPipeline conceptually describes all the state for vertex
* processing, fragment processing and blending geometry. When
* drawing the geometry for the crate this pipeline says to sample a
* single texture during fragment processing... */
data.crate_pipeline = cogl_pipeline_new ();
cogl_pipeline_set_layer_texture (data.crate_pipeline, 0, data.texture);
/* Since the box is made of multiple triangles that will overlap
* when drawn and we don't control the order they are drawn in, we
* enable depth testing to make sure that triangles that shouldn't
* be visible get culled by the GPU. */
cogl_depth_state_init (&depth_state);
cogl_depth_state_set_test_enabled (&depth_state, TRUE);
cogl_pipeline_set_depth_state (data.crate_pipeline, &depth_state, NULL);
/* Setup a Pango font map and context */
data.pango_font_map = COGL_PANGO_FONT_MAP (cogl_pango_font_map_new());
cogl_pango_font_map_set_use_mipmapping (data.pango_font_map, TRUE);
data.pango_context = cogl_pango_font_map_create_context (data.pango_font_map);
data.pango_font_desc = pango_font_description_new ();
pango_font_description_set_family (data.pango_font_desc, "Sans");
pango_font_description_set_size (data.pango_font_desc, 30 * PANGO_SCALE);
/* Setup the "Hello Cogl" text */
data.hello_label = pango_layout_new (data.pango_context);
pango_layout_set_font_description (data.hello_label, data.pango_font_desc);
pango_layout_set_text (data.hello_label, "Hello Cogl", -1);
pango_layout_get_extents (data.hello_label, NULL, &hello_label_size);
data.hello_label_width = PANGO_PIXELS (hello_label_size.width);
data.hello_label_height = PANGO_PIXELS (hello_label_size.height);
cogl_push_framebuffer (fb);
while (1)
{
paint (&data);
cogl_framebuffer_swap_buffers (fb);
}
return 0;
}

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