fishladder.c

   1 // Copyright (C) 2021 Harry Godden (hgn) - All Rights Reserved
   2
   3 //#define VG_STEAM
   4 #include "vg/vg.h"
   5
   6 SHADER_DEFINE( colour_shader,
   7
   8         // VERTEX
   9         "layout (location=0) in vec3 a_co;"
  10         "uniform mat4 uPv;"
  11         "uniform mat4 uMdl;"
  12         ""
  13         "void main()"
  14         "{"
  15         "       vec4 vert_pos = uPv * uMdl * vec4( a_co, 1.0 );"
  16         "       gl_Position = vert_pos;"
  17         "}",
  18
  19         // FRAGMENT
  20         "out vec4 FragColor;"
  21         "uniform vec4 uColour;"
  22         ""
  23         "void main()"
  24         "{"
  25         "       FragColor = uColour;"
  26         "}"
  27         ,
  28         UNIFORMS({ "uPv", "uMdl", "uColour" })
  29 )
  30
  31 mat4 m_projection;
  32 mat4 m_view;
  33 mat4 m_pv;
  34 mat4 m_mdl;
  35
  36 int main( int argc, char *argv[] )
  37 {
  38         vg_init( argc, argv, "FishLadder" );
  39 }
  40
  41 void vg_update(void)
  42 {
  43         // Update camera
  44         float ratio = (float)vg_window_y / (float)vg_window_x;
  45         float const size = 7.5f;
  46         glm_ortho( -size, size, -size*ratio, size*ratio, 0.1f, 100.f, m_projection );
  47
  48         glm_mat4_identity( m_view );
  49         glm_translate_z( m_view, -10.f );
  50         glm_rotate_x( m_view, -1.0f, m_view );
  51
  52         glm_mat4_mul( m_projection, m_view, m_pv );
  53
  54         // Get mouse ray
  55         vec3 ray_origin;
  56         vec3 ray_dir;
  57
  58         mat4 pv_inverse;
  59         vec4 vp = { 0.f, 0.f, vg_window_x, vg_window_y };
  60         glm_mat4_inv( m_pv, pv_inverse );
  61         glm_unprojecti( (vec3){ vg_mouse_x, vg_window_y-vg_mouse_y, -1.f }, pv_inverse, vp, ray_dir );
  62         glm_unprojecti( (vec3){ vg_mouse_x, vg_window_y-vg_mouse_y, 0.f }, pv_inverse, vp, ray_origin );
  63         glm_vec3_sub( ray_dir, ray_origin, ray_dir );
  64
  65         // Get floor tile intersection
  66         float ray_t = -ray_origin[1] / ray_dir[1];
  67
  68         vec3 tile_pos;
  69         glm_vec3_copy( ray_origin, tile_pos );
  70         glm_vec3_muladds( ray_dir, ray_t, tile_pos );
  71
  72         tile_pos[0] = floorf( tile_pos[0] + 0.5f );
  73         tile_pos[2] = floorf( tile_pos[2] + 0.5f );
  74
  75         glm_mat4_identity( m_mdl );
  76         glm_translate( m_mdl, tile_pos );
  77 }
  78
  79 GLuint tile_vao;
  80 GLuint tile_vbo;
  81
  82 void vg_render(void)
  83 {
  84         glViewport( 0,0, vg_window_x, vg_window_y );
  85
  86         glEnable( GL_DEPTH_TEST );
  87         glClearColor( 0.94f, 0.94f, 0.94f, 1.0f );
  88         glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  89
  90         SHADER_USE( colour_shader );
  91         glUniformMatrix4fv( SHADER_UNIFORM( colour_shader, "uPv" ), 1, GL_FALSE, (float *)m_pv );
  92         glUniform4f( SHADER_UNIFORM( colour_shader, "uColour" ), 0.5f, 0.5f, 0.5f, 1.0f );
  93
  94         glUniformMatrix4fv( SHADER_UNIFORM( colour_shader, "uMdl" ), 1, GL_FALSE, (float *)m_mdl );
  95
  96         glBindVertexArray( tile_vao );
  97         glDrawArrays( GL_TRIANGLES, 0, 6 );
  98 }
  99
 100 void vg_start(void)
 101 {
 102         SHADER_INIT( colour_shader );
 103
 104         glGenVertexArrays( 1, &tile_vao );
 105         glGenBuffers( 1, &tile_vbo );
 106
 107         float quad_mesh[] =
 108         {
 109                 -0.5f, 0.f, -0.5f,
 110                 -0.5f, 0.f, 0.5f,
 111                  0.5f, 0.f, 0.5f,
 112                 -0.5f, 0.f, -0.5f,
 113                  0.5f, 0.f, 0.5f,
 114                  0.5f, 0.f, -0.5f
 115         };
 116
 117         glBindVertexArray( tile_vao );
 118         glBindBuffer( GL_ARRAY_BUFFER, tile_vbo );
 119         glBufferData
 120         (
 121                 GL_ARRAY_BUFFER,
 122                 sizeof( quad_mesh ),
 123                 quad_mesh,
 124                 GL_STATIC_DRAW
 125         );
 126
 127         glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0 );
 128         glEnableVertexAttribArray( 0 );
 129
 130         VG_CHECK_GL();
 131 }
 132
 133 void vg_free(void)
 134 {
 135
 136 }
 137
 138 void vg_ui(void)
 139 {
 140
 141 }