@ -37,6 +37,7 @@
# include <stdlib.h>
# include <string.h>
# include <unistd.h>
# include <sys/time.h>
# include <drm_fourcc.h>
# include <xf86drm.h>
@ -125,6 +126,12 @@ struct window {
struct wl_callback * callback ;
bool initialized ;
bool wait_for_configure ;
struct {
GLuint program ;
GLuint pos ;
GLuint color ;
GLuint offset_uniform ;
} gl ;
} ;
static sig_atomic_t running = 1 ;
@ -426,6 +433,117 @@ static const struct zxdg_toplevel_v6_listener xdg_toplevel_listener = {
xdg_toplevel_handle_close ,
} ;
static const char * vert_shader_text =
" uniform float offset; \n "
" attribute vec4 pos; \n "
" attribute vec4 color; \n "
" varying vec4 v_color; \n "
" void main() { \n "
" gl_Position = pos + vec4(offset, offset, 0.0, 0.0); \n "
" v_color = color; \n "
" } \n " ;
static const char * frag_shader_text =
" precision mediump float; \n "
" varying vec4 v_color; \n "
" void main() { \n "
" gl_FragColor = v_color; \n "
" } \n " ;
static GLuint
create_shader ( const char * source , GLenum shader_type )
{
GLuint shader ;
GLint status ;
shader = glCreateShader ( shader_type ) ;
assert ( shader ! = 0 ) ;
glShaderSource ( shader , 1 , ( const char * * ) & source , NULL ) ;
glCompileShader ( shader ) ;
glGetShaderiv ( shader , GL_COMPILE_STATUS , & status ) ;
if ( ! status ) {
char log [ 1000 ] ;
GLsizei len ;
glGetShaderInfoLog ( shader , 1000 , & len , log ) ;
fprintf ( stderr , " Error: compiling %s: %*s \n " ,
shader_type = = GL_VERTEX_SHADER ? " vertex " : " fragment " ,
len , log ) ;
return 0 ;
}
return shader ;
}
static GLuint
create_and_link_program ( GLuint vert , GLuint frag )
{
GLint status ;
GLuint program = glCreateProgram ( ) ;
glAttachShader ( program , vert ) ;
glAttachShader ( program , frag ) ;
glLinkProgram ( program ) ;
glGetProgramiv ( program , GL_LINK_STATUS , & status ) ;
if ( ! status ) {
char log [ 1000 ] ;
GLsizei len ;
glGetProgramInfoLog ( program , 1000 , & len , log ) ;
fprintf ( stderr , " Error: linking: \n %*s \n " , len , log ) ;
return 0 ;
}
return program ;
}
static bool
window_set_up_gl ( struct window * window )
{
GLuint vert = create_shader ( vert_shader_text , GL_VERTEX_SHADER ) ;
GLuint frag = create_shader ( frag_shader_text , GL_FRAGMENT_SHADER ) ;
window - > gl . program = create_and_link_program ( vert , frag ) ;
glDeleteShader ( vert ) ;
glDeleteShader ( frag ) ;
window - > gl . pos = glGetAttribLocation ( window - > gl . program , " pos " ) ;
window - > gl . color = glGetAttribLocation ( window - > gl . program , " color " ) ;
glUseProgram ( window - > gl . program ) ;
window - > gl . offset_uniform =
glGetUniformLocation ( window - > gl . program , " offset " ) ;
return window - > gl . program ! = 0 ;
}
static void
destroy_window ( struct window * window )
{
int i ;
if ( window - > gl . program )
glDeleteProgram ( window - > gl . program ) ;
if ( window - > callback )
wl_callback_destroy ( window - > callback ) ;
for ( i = 0 ; i < NUM_BUFFERS ; i + + ) {
if ( window - > buffers [ i ] . buffer )
buffer_free ( & window - > buffers [ i ] ) ;
}
if ( window - > xdg_toplevel )
zxdg_toplevel_v6_destroy ( window - > xdg_toplevel ) ;
if ( window - > xdg_surface )
zxdg_surface_v6_destroy ( window - > xdg_surface ) ;
wl_surface_destroy ( window - > surface ) ;
free ( window ) ;
}
static struct window *
create_window ( struct display * display , int width , int height )
{
@ -486,31 +604,19 @@ create_window(struct display *display, int width, int height)
width , height ) ;
if ( ret < 0 )
return NULL ;
}
return window ;
goto error ;
}
static void
destroy_window ( struct window * window )
{
int i ;
if ( ! window_set_up_gl ( window ) )
goto error ;
if ( window - > callback )
wl_callback_destroy ( window - > callback ) ;
return window ;
for ( i = 0 ; i < NUM_BUFFERS ; i + + ) {
if ( window - > buffers [ i ] . buffer )
buffer_free ( & window - > buffers [ i ] ) ;
}
error :
if ( window )
destroy_window ( window ) ;
if ( window - > xdg_toplevel )
zxdg_toplevel_v6_destroy ( window - > xdg_toplevel ) ;
if ( window - > xdg_surface )
zxdg_surface_v6_destroy ( window - > xdg_surface ) ;
wl_surface_destroy ( window - > surface ) ;
free ( window ) ;
return NULL ;
}
static struct buffer *
@ -527,13 +633,67 @@ window_next_buffer(struct window *window)
static const struct wl_callback_listener frame_listener ;
/* Renders a square moving from the lower left corner to the
* upper right corner of the window . The square ' s vertices have
* the following colors :
*
* green + - - - - - + yellow
* | |
* | |
* red + - - - - - + blue
*/
static void
render ( struct window * window , struct buffer * buffer )
{
/* Complete a movement iteration in 5000 ms. */
static const uint64_t iteration_ms = 5000 ;
static const GLfloat verts [ 4 ] [ 2 ] = {
{ - 0.5 , - 0.5 } ,
{ - 0.5 , 0.5 } ,
{ 0.5 , - 0.5 } ,
{ 0.5 , 0.5 }
} ;
static const GLfloat colors [ 4 ] [ 3 ] = {
{ 1 , 0 , 0 } ,
{ 0 , 1 , 0 } ,
{ 0 , 0 , 1 } ,
{ 1 , 1 , 0 }
} ;
GLfloat offset ;
struct timeval tv ;
uint64_t time_ms ;
gettimeofday ( & tv , NULL ) ;
time_ms = tv . tv_sec * 1000 + tv . tv_usec / 1000 ;
/* Split time_ms in repeating windows of [0, iteration_ms) and map them
* to offsets in the [ - 0.5 , 0.5 ) range . */
offset = ( time_ms % iteration_ms ) / ( float ) iteration_ms - 0.5 ;
/* Direct all GL draws to the buffer through the FBO */
glBindFramebuffer ( GL_FRAMEBUFFER , buffer - > gl_fbo ) ;
glViewport ( 0 , 0 , window - > width , window - > height ) ;
glUniform1f ( window - > gl . offset_uniform , offset ) ;
glClearColor ( 0.0 , 0.0 , 0.0 , 1.0 ) ;
glClear ( GL_COLOR_BUFFER_BIT ) ;
glVertexAttribPointer ( window - > gl . pos , 2 , GL_FLOAT , GL_FALSE , 0 , verts ) ;
glVertexAttribPointer ( window - > gl . color , 3 , GL_FLOAT , GL_FALSE , 0 , colors ) ;
glEnableVertexAttribArray ( window - > gl . pos ) ;
glEnableVertexAttribArray ( window - > gl . color ) ;
glDrawArrays ( GL_TRIANGLE_STRIP , 0 , 4 ) ;
glDisableVertexAttribArray ( window - > gl . pos ) ;
glDisableVertexAttribArray ( window - > gl . color ) ;
}
static void
redraw ( void * data , struct wl_callback * callback , uint32_t time )
{
/* With a 60Hz redraw rate this completes a cycle in 3 seconds */
static const int MAX_STEP = 180 ;
static int step = 0 ;
static int step_dir = 1 ;
struct window * window = data ;
struct buffer * buffer ;
@ -545,19 +705,7 @@ redraw(void *data, struct wl_callback *callback, uint32_t time)
abort ( ) ;
}
/* Direct all GL draws to the buffer through the FBO */
glBindFramebuffer ( GL_FRAMEBUFFER , buffer - > gl_fbo ) ;
/* Cycle between 0 and MAX_STEP */
step + = step_dir ;
if ( step = = 0 | | step = = MAX_STEP )
step_dir = - step_dir ;
glClearColor ( 0.0 ,
( float ) step / MAX_STEP ,
1.0 - ( float ) step / MAX_STEP ,
1.0 ) ;
glClear ( GL_COLOR_BUFFER_BIT ) ;
render ( window , buffer ) ;
glFinish ( ) ;
wl_surface_attach ( window - > surface , buffer - > buffer , 0 , 0 ) ;