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 gpipeline;
  16
  17 struct framebuffer
  18 {
  19    GLuint fb, colour, rb;
  20    int div;
  21    GLuint format;
  22 };
  23
  24 static void render_water_texture( m4x3f camera );
  25 static void render_water_surface( m4x4f pv, m4x3f camera );
  26 static void render_world( m4x4f projection, m4x3f camera );
  27
  28 /*
  29  * http://www.terathon.com/lengyel/Lengyel-Oblique.pdf
  30  */
  31 static void plane_clip_projection( m4x4f mat, v4f plane )
  32 {
  33    v4f c =
  34    {
  35       (vg_signf(plane[0]) + mat[2][0]) / mat[0][0],
  36       (vg_signf(plane[1]) + mat[2][1]) / mat[1][1],
  37       -1.0f,
  38       (1.0f + mat[2][2]) / mat[3][2]
  39    };
  40
  41    v4_muls( plane, 2.0f / v4_dot(plane,c), c );
  42
  43    mat[0][2] = c[0];
  44    mat[1][2] = c[1];
  45    mat[2][2] = c[2] + 1.0f;
  46    mat[3][2] = c[3];
  47 }
  48
  49 static void pipeline_projection( m4x4f mat, float nearz, float farz )
  50 {
  51    m4x4_projection( mat,
  52          gpipeline.fov,
  53          (float)vg_window_x / (float)vg_window_y,
  54          nearz, farz );
  55 }
  56
  57 static void fb_use( struct framebuffer *fb )
  58 {
  59    if( !fb )
  60    {
  61       glBindFramebuffer( GL_FRAMEBUFFER, 0 );
  62       glViewport( 0, 0, vg_window_x, vg_window_y );
  63    }
  64    else
  65    {
  66       glBindFramebuffer( GL_FRAMEBUFFER, fb->fb );
  67       glViewport( 0, 0, vg_window_x / fb->div, vg_window_y / fb->div );
  68    }
  69 }
  70
  71 static void fb_init( struct framebuffer *fb )
  72 {
  73    i32 ix = vg_window_x / fb->div,
  74        iy = vg_window_y / fb->div;
  75
  76    glGenFramebuffers( 1, &fb->fb );
  77    glBindFramebuffer( GL_FRAMEBUFFER, fb->fb );
  78
  79    glGenTextures( 1, &fb->colour );
  80    glBindTexture( GL_TEXTURE_2D, fb->colour );
  81    glTexImage2D( GL_TEXTURE_2D, 0, fb->format, ix, iy,
  82          0, fb->format, GL_UNSIGNED_BYTE, NULL);
  83
  84    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
  85    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  86    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
  87          GL_TEXTURE_2D, fb->colour, 0);
  88
  89    glGenRenderbuffers( 1, &fb->rb );
  90    glBindRenderbuffer( GL_RENDERBUFFER, fb->rb );
  91    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, ix, iy );
  92
  93    glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
  94          GL_RENDERBUFFER, fb->rb );
  95 }
  96
  97 static void fb_bindtex( struct framebuffer *fb, int texture )
  98 {
  99    glActiveTexture( GL_TEXTURE0 + texture );
 100    glBindTexture( GL_TEXTURE_2D, fb->colour );
 101 }
 102
 103 static void fb_resize( struct framebuffer *fb )
 104 {
 105    i32 ix = vg_window_x / fb->div,
 106        iy = vg_window_y / fb->div;
 107
 108    glBindTexture( GL_TEXTURE_2D, fb->colour );
 109    glTexImage2D( GL_TEXTURE_2D, 0, fb->format, ix, iy, 0,
 110          fb->format, GL_UNSIGNED_BYTE, NULL );
 111
 112    glBindRenderbuffer( GL_RENDERBUFFER, fb->rb );
 113    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, ix, iy );
 114 }
 115
 116 static void render_fb_resize(void)
 117 {
 118    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_background );
 119    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vg_window_x, vg_window_y, 0,
 120          GL_RGB, GL_UNSIGNED_BYTE, NULL );
 121 }
 122
 123 static void render_init(void)
 124 {
 125    glGenFramebuffers( 1, &gpipeline.fb_background );
 126    glBindFramebuffer( GL_FRAMEBUFFER, gpipeline.fb_background );
 127
 128    glGenTextures( 1, &gpipeline.rgb_background );
 129    glBindTexture( GL_TEXTURE_2D, gpipeline.rgb_background );
 130    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGB, vg_window_x, vg_window_y,
 131          0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
 132
 133    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 134    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 135    glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
 136          GL_TEXTURE_2D,
 137          gpipeline.rgb_background, 0);
 138
 139    float quad[] = { 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,
 140                     0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f };
 141
 142    glGenVertexArrays( 1, &gpipeline.fsquad.vao );
 143    glGenBuffers( 1, &gpipeline.fsquad.vbo );
 144    glBindVertexArray( gpipeline.fsquad.vao );
 145    glBindBuffer( GL_ARRAY_BUFFER, gpipeline.fsquad.vbo );
 146    glBufferData( GL_ARRAY_BUFFER, sizeof(quad), quad, GL_STATIC_DRAW );
 147    glBindVertexArray( gpipeline.fsquad.vao );
 148    glVertexAttribPointer( 0, 2, GL_FLOAT, GL_FALSE,
 149          sizeof(float)*2, (void*)0 );
 150    glEnableVertexAttribArray( 0 );
 151    VG_CHECK_GL();
 152 }
 153
 154 static void render_fsquad(void)
 155 {
 156    glBindVertexArray( gpipeline.fsquad.vao );
 157    glDrawArrays( GL_TRIANGLES, 0, 6 );
 158 }
 159
 160 #endif /* RENDER_H */