src/vg/vg_loader.h

   1 /*
   2  * Copyright 2021-2022 (C) Mount0 Software, Harry Godden - All Rights Reserved
   3  * -----------------------------------------------------------------------------
   4  *
   5  * Splash / load screen
   6  *
   7  * -----------------------------------------------------------------------------
   8  */
   9
  10 #ifndef VG_LOADER_H
  11 #define VG_LOADER_H
  12
  13 #include "common.h"
  14
  15 static struct vg_shader _shader_loader =
  16 {
  17    .name = "[vg] loader",
  18    .link = NULL,
  19    .vs =
  20    {
  21       .orig_file = NULL,
  22       .static_src = ""
  23       "layout (location=0) in vec2 a_co;"
  24       "out vec2 aUv;"
  25       "void main()"
  26       "{"
  27          "gl_Position = vec4(a_co*2.0-1.0,0.0,1.0);"
  28          "aUv = a_co;"
  29       "}"
  30    },
  31    .fs =
  32    {
  33       .orig_file = NULL,
  34       .static_src =
  35
  36       "out vec4 FragColor;"
  37       "uniform float uTime;"
  38       "in vec2 aUv;"
  39
  40       "void main()"
  41       "{"
  42          "float dither=fract(dot(vec2(171.0,231.0),gl_FragCoord.xy)/71.0)-0.5;"
  43          "float grad = 1.0-(aUv.y*0.5+0.5);"
  44          "float fmt1 = step( 0.5, grad+dither );"
  45
  46          "vec3 col = 0.5+0.5*sin( uTime + aUv.xyx + vec3(0.0,2.0,4.0) );"
  47
  48          "FragColor = vec4(col*grad*fmt1,1.0);"
  49       "}"
  50    }
  51 };
  52
  53 static struct vg_loader
  54 {
  55    /* Shutdown steps */
  56    struct loader_free_step
  57    {
  58       void (*fn_free)(void *);
  59       void *data;
  60    }
  61    step_buffer[16];
  62    u32 step_count, step_action;
  63
  64    GLuint vao, vbo;
  65 }
  66 vg_loader;
  67
  68 VG_STATIC void vg_loader_init(void)
  69 {
  70    float quad[] = { 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,
  71                     0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f };
  72
  73    glGenVertexArrays( 1, &vg_loader.vao );
  74    glGenBuffers( 1, &vg_loader.vbo );
  75    glBindVertexArray( vg_loader.vao );
  76    glBindBuffer( GL_ARRAY_BUFFER, vg_loader.vbo );
  77    glBufferData( GL_ARRAY_BUFFER, sizeof(quad), quad, GL_STATIC_DRAW );
  78    glBindVertexArray( vg_loader.vao );
  79    glVertexAttribPointer( 0, 2, GL_FLOAT, GL_FALSE, sizeof(float)*2, (void*)0 );
  80    glEnableVertexAttribArray( 0 );
  81
  82    VG_CHECK_GL_ERR();
  83
  84    if( !vg_shader_compile( &_shader_loader ) )
  85       vg_fatal_exit_loop( "failed to compile shader" );
  86 }
  87
  88 VG_STATIC void vg_loader_free(void)
  89 {
  90    vg_info( "vg_loader_free\n" );
  91    glDeleteVertexArrays( 1, &vg_loader.vao );
  92    glDeleteBuffers( 1, &vg_loader.vbo );
  93
  94    for( int i=0; i<vg_loader.step_count; i++ )
  95    {
  96       struct loader_free_step *step =
  97          &vg_loader.step_buffer[vg_loader.step_count -1 -i];
  98
  99       vg_info( " -> %p\n", step->fn_free );
 100       step->fn_free( step->data );
 101    }
 102
 103    vg_info( "done\n" );
 104 }
 105
 106 VG_STATIC float hue_to_rgb( float p, float q, float t )
 107 {
 108    if(t < 0.0f) t += 1.0f;
 109    if(t > 1.0f) t -= 1.0f;
 110    if(t < 1.0f/6.0f) return p + (q - p) * 6.0f * t;
 111    if(t < 1.0f/2.0f) return q;
 112    if(t < 2.0f/3.0f) return p + (q - p) * (2.0f/3.0f - t) * 6.0f;
 113    return p;
 114 }
 115
 116 VG_STATIC void vg_render_log(void)
 117 {
 118    ui_begin( vg.window_x, vg.window_y );
 119
 120    int const fh = 14;
 121    int lines_screen_max = ((vg.window_y/fh)-2),
 122        lines_max_draw = VG_MIN( lines_screen_max, vg_list_size(vg_log.buffer) ),
 123        lines_to_draw  = VG_MIN( lines_max_draw, vg_log.buffer_line_count );
 124
 125         int ptr = vg_log.buffer_line_current;
 126
 127         vg_uictx.cursor[0] = 0;
 128         vg_uictx.cursor[1] = lines_to_draw*fh;
 129    vg_uictx.cursor[3] = fh;
 130         ui_fill_x();
 131
 132    for( int i=0; i<lines_to_draw; i ++ )
 133    {
 134       ptr --;
 135
 136       if( ptr < 0 )
 137          ptr = vg_list_size( vg_log.buffer )-1;
 138
 139       ui_text( vg_uictx.cursor, vg_log.buffer[ptr], 1, 0 );
 140       vg_uictx.cursor[1] -= fh;
 141    }
 142
 143    ui_resolve();
 144    ui_draw( NULL );
 145 }
 146
 147 VG_STATIC void vg_loader_render(void)
 148 {
 149    glViewport( 0,0, vg.window_x, vg.window_y );
 150    glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 151    glClearColor( 0.0f, 0.0f, 0.0f, 1.0f );
 152    glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 153
 154    glUseProgram( _shader_loader.id );
 155         glUniform1f( glGetUniformLocation( _shader_loader.id, "uTime" ), vg.time );
 156
 157    glBindVertexArray( vg_loader.vao );
 158    glDrawArrays( GL_TRIANGLES, 0, 6 );
 159
 160    vg_render_log();
 161 }
 162
 163
 164 VG_STATIC void vg_load_full(void);
 165
 166 VG_STATIC void vg_loader_thread(void * nothing)
 167 {
 168    vg_thread_info.gl_context_level = 0;
 169    vg_thread_info.purpose = k_thread_purpose_loader;
 170    vg_set_thread_name( "[vg] Loader" );
 171
 172    /* Run client loader */
 173    vg_load_full();
 174    vg_semaphore_post( &vg.sem_loader );
 175 }
 176
 177 VG_STATIC void vg_loader_start(void)
 178 {
 179    vg_semaphore_wait( &vg.sem_loader );
 180    vg_thread_run( vg_loader_thread, NULL );
 181 }
 182
 183 /* this is maybe probably unused now */
 184 VG_STATIC void vg_free_libc_malloced( void *data )
 185 {
 186    free( data );
 187 }
 188
 189 VG_STATIC void vg_loader_push_free_step( struct loader_free_step step )
 190 {
 191    if( vg_loader.step_count == vg_list_size(vg_loader.step_buffer) )
 192       vg_fatal_exit_loop( "Too many free steps" );
 193
 194    vg_loader.step_buffer[ vg_loader.step_count ++ ] = step;
 195 }
 196
 197 /*
 198  * Schedule something to be ran now, freed later. Checks in with engine status
 199  */
 200 VG_STATIC void vg_loader_highwater( void( *fn_load )(void),
 201                                  void( *fn_free )(void *), void *data )
 202 {
 203    if( fn_load )
 204       fn_load();
 205
 206    if( fn_free )
 207    {
 208       struct loader_free_step step;
 209       step.data = data;
 210       step.fn_free = fn_free;
 211
 212       vg_loader_push_free_step( step );
 213    }
 214    else
 215    {
 216       if( data )
 217       {
 218          struct loader_free_step step;
 219          step.data = data;
 220          step.fn_free = vg_free_libc_malloced;
 221
 222          vg_loader_push_free_step( step );
 223       }
 224    }
 225
 226    vg_ensure_engine_running();
 227 }
 228
 229 #endif /* VG_LOADER_H */