render.h

   1 #ifndef RENDER_H
   2 #define RENDER_H
   3
   4 #include "common.h"
   5 #include "model.h"
   6
   7 static struct pipeline
   8 {
   9    float fov;
  10    glmesh fsquad;
  11
  12    GLuint fb_background,
  13           rgb_background;
  14
  15    /* STD140 */
  16    struct ub_world_lighting
  17    {
  18       /* v3f (padded) */
  19       v4f g_directional,
  20           g_sun_colour,
  21           g_shadow_colour;
  22
  23       v4f g_water_plane,
  24           g_depth_bounds;
  25       float g_water_fog;
  26    }
  27    ub_world_lighting;
  28
  29    GLuint fb_depthmap, rgb_depthmap;
  30    GLuint ubo_world_lighting,
  31           ubo_world;
  32 }
  33 gpipeline;
  34
  35 static void render_water_texture( m4x3f camera );
  36 static void render_water_surface( m4x4f pv, m4x3f camera );
  37 static void render_world( m4x4f projection, m4x3f camera );
  38 static void render_world_depth( m4x4f projection, m4x3f camera );
  39
  40 /*
  41  * Matrix Projections
  42  */
  43 /*
  44  * http://www.terathon.com/lengyel/Lengyel-Oblique.pdf
  45  */
  46 static void plane_clip_projection( m4x4f mat, v4f plane )
  47 {
  48    v4f c =
  49    {
  50       (vg_signf(plane[0]) + mat[2][0]) / mat[0][0],
  51       (vg_signf(plane[1]) + mat[2][1]) / mat[1][1],
  52       -1.0f,
  53       (1.0f + mat[2][2]) / mat[3][2]
  54    };
  55
  56    v4_muls( plane, 2.0f / v4_dot(plane,c), c );
  57
  58    mat[0][2] = c[0];
  59    mat[1][2] = c[1];
  60    mat[2][2] = c[2] + 1.0f;
  61    mat[3][2] = c[3];
  62 }
  63
  64 static void pipeline_projection( m4x4f mat, float nearz, float farz )
  65 {
  66    m4x4_projection( mat,
  67          gpipeline.fov,
  68          (float)vg_window_x / (float)vg_window_y,
  69          nearz, farz );
  70 }
  71
  72 /*
  73  * Shaders
  74  */
  75 static void shader_link_standard_ub( GLuint shader, int texture_id )
  76 {
  77    GLuint idx = glGetUniformBlockIndex( shader, "ub_world_lighting" );
  78    glUniformBlockBinding( shader, idx, 0 );
  79
  80    glActiveTexture( GL_TEXTURE0 + texture_id );
  81    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_depthmap );
  82    glUniform1i( glGetUniformLocation( shader, "g_world_depth" ), texture_id );
  83 }
  84
  85 static void render_update_lighting_ub(void)
  86 {
  87    glBindBuffer( GL_UNIFORM_BUFFER, gpipeline.ubo_world_lighting );
  88
  89    glBufferSubData( GL_UNIFORM_BUFFER, 0, sizeof(struct ub_world_lighting),
  90          &gpipeline.ub_world_lighting );
  91 }
  92
  93 static void render_alloc_ub(void)
  94 {
  95    glGenBuffers( 1, &gpipeline.ubo_world_lighting );
  96    glBindBuffer( GL_UNIFORM_BUFFER, gpipeline.ubo_world_lighting );
  97    glBufferData( GL_UNIFORM_BUFFER, sizeof(struct ub_world_lighting),
  98          NULL, GL_DYNAMIC_DRAW );
  99
 100    render_update_lighting_ub();
 101    glBindBufferBase( GL_UNIFORM_BUFFER, 0, gpipeline.ubo_world_lighting );
 102 }
 103
 104 /*
 105  * Framebuffers
 106  */
 107 struct framebuffer
 108 {
 109    GLuint fb, colour, rb;
 110    int div;
 111    GLuint format;
 112 };
 113
 114 static void fb_use( struct framebuffer *fb )
 115 {
 116    if( !fb )
 117    {
 118       glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 119       glViewport( 0, 0, vg_window_x, vg_window_y );
 120    }
 121    else
 122    {
 123       glBindFramebuffer( GL_FRAMEBUFFER, fb->fb );
 124       glViewport( 0, 0, vg_window_x / fb->div, vg_window_y / fb->div );
 125    }
 126 }
 127
 128 static void fb_init( struct framebuffer *fb )
 129 {
 130    i32 ix = vg_window_x / fb->div,
 131        iy = vg_window_y / fb->div;
 132
 133    glGenFramebuffers( 1, &fb->fb );
 134    glBindFramebuffer( GL_FRAMEBUFFER, fb->fb );
 135
 136    glGenTextures( 1, &fb->colour );
 137    glBindTexture( GL_TEXTURE_2D, fb->colour );
 138    glTexImage2D( GL_TEXTURE_2D, 0, fb->format, ix, iy,
 139          0, fb->format, GL_UNSIGNED_BYTE, NULL);
 140
 141    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 142    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 143    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 144          GL_TEXTURE_2D, fb->colour, 0);
 145
 146    glGenRenderbuffers( 1, &fb->rb );
 147    glBindRenderbuffer( GL_RENDERBUFFER, fb->rb );
 148    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, ix, iy );
 149
 150    glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
 151          GL_RENDERBUFFER, fb->rb );
 152 }
 153
 154 static void fb_bindtex( struct framebuffer *fb, int texture )
 155 {
 156    glActiveTexture( GL_TEXTURE0 + texture );
 157    glBindTexture( GL_TEXTURE_2D, fb->colour );
 158 }
 159
 160 static void fb_resize( struct framebuffer *fb )
 161 {
 162    i32 ix = vg_window_x / fb->div,
 163        iy = vg_window_y / fb->div;
 164
 165    glBindTexture( GL_TEXTURE_2D, fb->colour );
 166    glTexImage2D( GL_TEXTURE_2D, 0, fb->format, ix, iy, 0,
 167          fb->format, GL_UNSIGNED_BYTE, NULL );
 168
 169    glBindRenderbuffer( GL_RENDERBUFFER, fb->rb );
 170    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, ix, iy );
 171 }
 172
 173 static void render_fb_resize(void)
 174 {
 175    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_background );
 176    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vg_window_x, vg_window_y, 0,
 177          GL_RGB, GL_UNSIGNED_BYTE, NULL );
 178 }
 179
 180 /*
 181  * Vg
 182  */
 183 static void render_init(void)
 184 {
 185    glGenFramebuffers( 1, &gpipeline.fb_background );
 186    glBindFramebuffer( GL_FRAMEBUFFER, gpipeline.fb_background );
 187
 188    glGenTextures( 1, &gpipeline.rgb_background );
 189    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_background );
 190    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vg_window_x, vg_window_y,
 191          0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
 192
 193    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 194    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 195    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 196          GL_TEXTURE_2D,
 197          gpipeline.rgb_background, 0);
 198
 199    /*
 200     * World depth map, maybe this should be moved to world.h
 201     * TODO: review
 202     */
 203    glGenFramebuffers( 1, &gpipeline.fb_depthmap );
 204    glBindFramebuffer( GL_FRAMEBUFFER, gpipeline.fb_depthmap );
 205
 206    glGenTextures( 1, &gpipeline.rgb_depthmap );
 207    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_depthmap );
 208    glTexImage2D( GL_TEXTURE_2D, 0, GL_R32F, 1024, 1024, 0,
 209          GL_RED, GL_FLOAT, NULL );
 210    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 211    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 212    vg_tex2d_clamp();
 213
 214    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 215          GL_TEXTURE_2D,
 216          gpipeline.rgb_depthmap, 0);
 217
 218    float quad[] = { 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,
 219                     0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f };
 220
 221    glGenVertexArrays( 1, &gpipeline.fsquad.vao );
 222    glGenBuffers( 1, &gpipeline.fsquad.vbo );
 223    glBindVertexArray( gpipeline.fsquad.vao );
 224    glBindBuffer( GL_ARRAY_BUFFER, gpipeline.fsquad.vbo );
 225    glBufferData( GL_ARRAY_BUFFER, sizeof(quad), quad, GL_STATIC_DRAW );
 226    glBindVertexArray( gpipeline.fsquad.vao );
 227    glVertexAttribPointer( 0, 2, GL_FLOAT, GL_FALSE,
 228          sizeof(float)*2, (void*)0 );
 229    glEnableVertexAttribArray( 0 );
 230    VG_CHECK_GL();
 231
 232    render_alloc_ub();
 233 }
 234
 235 static void render_free(void)
 236 {
 237    /* TODO: ... */
 238 }
 239
 240 /*
 241  * Utility
 242  */
 243 static void render_fsquad(void)
 244 {
 245    glBindVertexArray( gpipeline.fsquad.vao );
 246    glDrawArrays( GL_TRIANGLES, 0, 6 );
 247 }
 248
 249 #endif /* RENDER_H */