render.h

   1 /*
   2  * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
   3  */
   4
   5 #include "common.h"
   6 #include "model.h"
   7
   8 #include "shaders/blit.h"
   9 #include "shaders/standard.h"
  10 #include "shaders/vblend.h"
  11 #include "shaders/unlit.h"
  12
  13 static void render_water_texture( m4x3f camera );
  14 static void render_water_surface( m4x4f pv, m4x3f camera );
  15 static void render_world( m4x4f projection, m4x3f camera );
  16 static void shader_link_standard_ub( GLuint shader, int texture_id );
  17 static void render_world_depth( m4x4f projection, m4x3f camera );
  18
  19 #ifndef RENDER_H
  20 #define RENDER_H
  21
  22 struct framebuffer
  23 {
  24    GLuint fb, colour, rb;
  25    int div;
  26    GLuint format;
  27
  28    int allocated;
  29 };
  30
  31 static struct pipeline
  32 {
  33    float fov;
  34    glmesh fsquad;
  35
  36    GLuint fb_background,
  37           rgb_background;
  38
  39    /* STD140 */
  40    struct ub_world_lighting
  41    {
  42       /* v3f (padded) */
  43       v4f g_light_colours[3],
  44           g_light_directions[3],
  45           g_ambient_colour;
  46
  47       v4f g_water_plane,
  48           g_depth_bounds;
  49
  50       float g_water_fog;
  51       int g_light_count;
  52       int g_light_preview;
  53    }
  54    ub_world_lighting;
  55
  56    struct light_widget
  57    {
  58       int enabled;
  59       v2f dir;
  60       v3f colour;
  61    }
  62    widgets[3];
  63
  64    float shadow_spread, shadow_length;
  65
  66    GLuint fb_depthmap, rgb_depthmap;
  67    GLuint ubo_world_lighting,
  68           ubo_world;
  69
  70    int ready;
  71 }
  72 gpipeline =
  73 {
  74    .widgets =
  75    {
  76       {
  77          .enabled = 1,
  78          .colour = { 1.36f, 1.35f, 1.01f },
  79          .dir = { 0.63f, -0.08f }
  80       },
  81       {
  82          .enabled = 1,
  83          .colour = { 0.33f, 0.56f, 0.64f },
  84          .dir = { -2.60f, -0.13f }
  85       },
  86       {
  87          .enabled = 1,
  88          .colour = { 0.05f, 0.05f, 0.23f },
  89          .dir = { 2.60f, -0.84f }
  90       }
  91    },
  92    .shadow_spread = 0.65f,
  93    .shadow_length = 9.50f,
  94
  95    .ub_world_lighting =
  96    {
  97       .g_ambient_colour = { 0.09f, 0.03f, 0.07f }
  98    }
  99 };
 100
 101 /*
 102  * Matrix Projections
 103  */
 104 /*
 105  * http://www.terathon.com/lengyel/Lengyel-Oblique.pdf
 106  */
 107 static void plane_clip_projection( m4x4f mat, v4f plane )
 108 {
 109    v4f c =
 110    {
 111       (vg_signf(plane[0]) + mat[2][0]) / mat[0][0],
 112       (vg_signf(plane[1]) + mat[2][1]) / mat[1][1],
 113       -1.0f,
 114       (1.0f + mat[2][2]) / mat[3][2]
 115    };
 116
 117    v4_muls( plane, 2.0f / v4_dot(plane,c), c );
 118
 119    mat[0][2] = c[0];
 120    mat[1][2] = c[1];
 121    mat[2][2] = c[2] + 1.0f;
 122    mat[3][2] = c[3];
 123 }
 124
 125 static void pipeline_projection( m4x4f mat, float nearz, float farz )
 126 {
 127    m4x4_projection( mat,
 128          gpipeline.fov,
 129          (float)vg_window_x / (float)vg_window_y,
 130          nearz, farz );
 131 }
 132
 133 /*
 134  * Shaders
 135  */
 136 static void shader_link_standard_ub( GLuint shader, int texture_id )
 137 {
 138    GLuint idx = glGetUniformBlockIndex( shader, "ub_world_lighting" );
 139    glUniformBlockBinding( shader, idx, 0 );
 140
 141    glActiveTexture( GL_TEXTURE0 + texture_id );
 142    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_depthmap );
 143    glUniform1i( glGetUniformLocation( shader, "g_world_depth" ), texture_id );
 144 }
 145
 146 static void render_update_lighting_ub(void)
 147 {
 148    struct ub_world_lighting *winf = &gpipeline.ub_world_lighting;
 149    int c = 0;
 150
 151    for( int i=0; i<3; i++ )
 152    {
 153       struct light_widget *lw = &gpipeline.widgets[i];
 154
 155       if( lw->enabled )
 156       {
 157          float pitch = lw->dir[0],
 158                yaw = lw->dir[1],
 159                xz = cosf( pitch );
 160
 161          v3_copy( (v3f){ xz*cosf(yaw), sinf(pitch), xz*sinf(yaw) },
 162                winf->g_light_directions[c] );
 163          v3_copy( lw->colour, winf->g_light_colours[c] );
 164
 165          c ++;
 166       }
 167    }
 168
 169    winf->g_light_count = c;
 170    winf->g_light_directions[0][3] = gpipeline.shadow_length;
 171    winf->g_light_colours[0][3] = gpipeline.shadow_spread;
 172
 173    glBindBuffer( GL_UNIFORM_BUFFER, gpipeline.ubo_world_lighting );
 174    glBufferSubData( GL_UNIFORM_BUFFER, 0, sizeof(struct ub_world_lighting),
 175          &gpipeline.ub_world_lighting );
 176 }
 177
 178 /*
 179  * Framebuffers
 180  */
 181
 182 static void fb_use( struct framebuffer *fb )
 183 {
 184    if( !fb )
 185    {
 186       glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 187       glViewport( 0, 0, vg_window_x, vg_window_y );
 188    }
 189    else
 190    {
 191       glBindFramebuffer( GL_FRAMEBUFFER, fb->fb );
 192       glViewport( 0, 0, vg_window_x / fb->div, vg_window_y / fb->div );
 193    }
 194 }
 195
 196 static void fb_init( struct framebuffer *fb )
 197 {
 198    i32 ix = vg_window_x / fb->div,
 199        iy = vg_window_y / fb->div;
 200
 201    glGenFramebuffers( 1, &fb->fb );
 202    glBindFramebuffer( GL_FRAMEBUFFER, fb->fb );
 203
 204    glGenTextures( 1, &fb->colour );
 205    glBindTexture( GL_TEXTURE_2D, fb->colour );
 206    glTexImage2D( GL_TEXTURE_2D, 0, fb->format, ix, iy,
 207          0, fb->format, GL_UNSIGNED_BYTE, NULL);
 208
 209    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 210    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 211    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 212          GL_TEXTURE_2D, fb->colour, 0);
 213
 214    glGenRenderbuffers( 1, &fb->rb );
 215    glBindRenderbuffer( GL_RENDERBUFFER, fb->rb );
 216    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, ix, iy );
 217
 218    glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
 219          GL_RENDERBUFFER, fb->rb );
 220    glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 221
 222    VG_CHECK_GL_ERR();
 223    fb->allocated = 1;
 224 }
 225
 226 static void fb_free( struct framebuffer *fb )
 227 {
 228    glDeleteTextures( 1, &fb->colour );
 229    glDeleteFramebuffers( 1, &fb->fb );
 230 }
 231
 232 static void fb_bindtex( struct framebuffer *fb, int texture )
 233 {
 234    glActiveTexture( GL_TEXTURE0 + texture );
 235    glBindTexture( GL_TEXTURE_2D, fb->colour );
 236 }
 237
 238 static void fb_resize( struct framebuffer *fb )
 239 {
 240    if( !fb->allocated )
 241       return;
 242
 243    i32 ix = vg_window_x / fb->div,
 244        iy = vg_window_y / fb->div;
 245
 246    glBindTexture( GL_TEXTURE_2D, fb->colour );
 247    glTexImage2D( GL_TEXTURE_2D, 0, fb->format, ix, iy, 0,
 248          fb->format, GL_UNSIGNED_BYTE, NULL );
 249
 250    glBindRenderbuffer( GL_RENDERBUFFER, fb->rb );
 251    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, ix, iy );
 252 }
 253
 254 static void render_fb_resize(void)
 255 {
 256    if( gpipeline.ready )
 257    {
 258       glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_background );
 259       glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vg_window_x, vg_window_y, 0,
 260             GL_RGB, GL_UNSIGNED_BYTE, NULL );
 261    }
 262 }
 263
 264 /* used for drawing player onto */
 265 static void render_init_temp_buffer(void)
 266 {
 267    vg_info( "[render] Allocate temporary framebuffer\n" );
 268
 269    glGenFramebuffers( 1, &gpipeline.fb_background );
 270    glBindFramebuffer( GL_FRAMEBUFFER, gpipeline.fb_background );
 271
 272    glGenTextures( 1, &gpipeline.rgb_background );
 273    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_background );
 274    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vg_window_x, vg_window_y,
 275          0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
 276
 277    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 278    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 279    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 280          GL_TEXTURE_2D,
 281          gpipeline.rgb_background, 0);
 282
 283    VG_CHECK_GL_ERR();
 284 }
 285
 286 /* used for drawing world depth from the top view, used in our water and
 287  * lighting calculations */
 288 static void render_init_depthmap_buffer(void)
 289 {
 290    vg_info( "[render] Allocate depth map buffer\n" );
 291
 292    glGenFramebuffers( 1, &gpipeline.fb_depthmap );
 293    glBindFramebuffer( GL_FRAMEBUFFER, gpipeline.fb_depthmap );
 294
 295    glGenTextures( 1, &gpipeline.rgb_depthmap );
 296    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_depthmap );
 297    glTexImage2D( GL_TEXTURE_2D, 0, GL_R32F, 1024, 1024, 0,
 298          GL_RED, GL_FLOAT, NULL );
 299    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 300    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 301    vg_tex2d_clamp();
 302
 303    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 304          GL_TEXTURE_2D,
 305          gpipeline.rgb_depthmap, 0);
 306
 307    VG_CHECK_GL_ERR();
 308 }
 309
 310 static void render_init_fs_quad(void)
 311 {
 312    vg_info( "[render] Allocate quad\n" );
 313
 314    float quad[] = { 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,
 315                     0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f };
 316
 317    glGenVertexArrays( 1, &gpipeline.fsquad.vao );
 318    glGenBuffers( 1, &gpipeline.fsquad.vbo );
 319    glBindVertexArray( gpipeline.fsquad.vao );
 320    glBindBuffer( GL_ARRAY_BUFFER, gpipeline.fsquad.vbo );
 321    glBufferData( GL_ARRAY_BUFFER, sizeof(quad), quad, GL_STATIC_DRAW );
 322    glBindVertexArray( gpipeline.fsquad.vao );
 323    glVertexAttribPointer( 0, 2, GL_FLOAT, GL_FALSE,
 324          sizeof(float)*2, (void*)0 );
 325    glEnableVertexAttribArray( 0 );
 326
 327    VG_CHECK_GL_ERR();
 328 }
 329
 330 static void render_init_uniform_buffers(void)
 331 {
 332    vg_info( "[render] Allocate uniform buffer\n" );
 333
 334    glGenBuffers( 1, &gpipeline.ubo_world_lighting );
 335    glBindBuffer( GL_UNIFORM_BUFFER, gpipeline.ubo_world_lighting );
 336    glBufferData( GL_UNIFORM_BUFFER, sizeof(struct ub_world_lighting),
 337          NULL, GL_DYNAMIC_DRAW );
 338
 339    render_update_lighting_ub();
 340    glBindBufferBase( GL_UNIFORM_BUFFER, 0, gpipeline.ubo_world_lighting );
 341
 342    VG_CHECK_GL_ERR();
 343 }
 344
 345 static void render_init(void)
 346 {
 347    shader_blit_register();
 348    shader_standard_register();
 349    shader_vblend_register();
 350    shader_unlit_register();
 351
 352    vg_acquire_thread_sync();
 353    {
 354       render_init_temp_buffer();
 355       render_init_depthmap_buffer();
 356       render_init_fs_quad();
 357       render_init_uniform_buffers();
 358
 359       glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 360       gpipeline.ready = 1;
 361    }
 362
 363    vg_release_thread_sync();
 364 }
 365
 366 static void render_free(void *_)
 367 {
 368    glDeleteBuffers( 1, &gpipeline.ubo_world_lighting );
 369
 370    glDeleteVertexArrays( 1, &gpipeline.fsquad.vao );
 371    glDeleteBuffers( 1, &gpipeline.fsquad.vbo );
 372
 373    glDeleteFramebuffers( 1, &gpipeline.fb_depthmap );
 374    glDeleteTextures( 1, &gpipeline.rgb_depthmap );
 375
 376    glDeleteFramebuffers( 1, &gpipeline.fb_background );
 377    glDeleteTextures( 1, &gpipeline.rgb_background );
 378 }
 379
 380 /*
 381  * Utility
 382  */
 383 static void render_fsquad(void)
 384 {
 385    glBindVertexArray( gpipeline.fsquad.vao );
 386    glDrawArrays( GL_TRIANGLES, 0, 6 );
 387 }
 388
 389 #endif /* RENDER_H */