polyadvent

A game engine from scratch in C
git clone git://jb55.com/polyadvent
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ui.c (2964B)

      1 
      2 #include "ui.h"
      3 #include "mat4.h"
      4 #include "vbo.h"
      5 #include "geometry.h"
      6 #include "util.h"
      7 #include "common.h"
      8 #include "lens.h"
      9 
     10 
     11 //  v1------v0
     12 //  |       |
     13 //  |       |
     14 //  |       |
     15 //  v2------v3
     16 
     17 static GLfloat quad_vertices[] = {
     18   0.5, 0.5, 0.5,  -0.5, 0.5, 0.5,  -0.5,-0.5, 0.5,   0.5,-0.5, 0.5,    // v0-v1-v2-v3 front
     19 };
     20 
     21 
     22 static GLfloat quad_normals[] = {
     23   0, 0, 1,   0, 0, 1,   0, 0, 1,   0, 0, 1, // front
     24 };
     25 
     26 static GLuint quad_indices[] = {0, 1, 2,  0, 2, 3};
     27 
     28 
     29 static GLfloat quad_uvs[] =
     30 {
     31     1.0, 1.0, // v0
     32     0.0, 1.0, // v1
     33     0.0, 0.0, // v2
     34     1.0, 0.0, // v3
     35 };
     36 
     37 
     38 static void create_quad(struct geometry_id *id)
     39 {
     40     struct make_geometry mkgeom = {
     41         .indices = quad_indices,
     42         .vertices = quad_vertices,
     43         .normals = quad_normals,
     44         .tex_coords = quad_uvs,
     45         .num_indices = ARRAY_SIZE(quad_indices),
     46         .num_verts = ARRAY_SIZE(quad_vertices)/3,
     47         .num_uv_components = 2
     48     };
     49     init_id(id);
     50     struct geometry *geom = new_geometry(id);
     51     make_buffer_geometry(&mkgeom, geom);
     52     check_gl();
     53 }
     54 
     55 
     56 #define UI_LENS(field, typ) { #field, offsetof(struct ui, field), DATA_ID_##typ }
     57 static struct lens ui_lenses[] = {
     58 	UI_LENS(uipos, VEC2),
     59 	UI_LENS(uisize, VEC2),
     60 	UI_LENS(mvp, MAT4P),
     61 	UI_LENS(texture, INT),
     62 };
     63 #undef UI_LENS
     64 
     65 static struct structure_binding ui_bindings[] = {
     66     { ui_lenses, ARRAY_SIZE(ui_lenses) },
     67 };
     68 
     69 void render_ui(struct ui *ui, float *view) {
     70 	glDisable(GL_DEPTH_TEST);
     71 	glUseProgram(ui->shader->handle);
     72 	check_gl();
     73 
     74 	ui->uipos[0] = 0.01;
     75 	ui->uipos[1] = 0.01;
     76 	ui->uisize[0] = 0.4;
     77 	ui->uisize[1] = 0.4;
     78 	ui->texture = 0;
     79 
     80 	void *structures[] = { ui };
     81 
     82 	assert(ARRAY_SIZE(structures) == ARRAY_SIZE(ui_bindings));
     83 	
     84 	ui->mvp = ui->ortho;
     85 	//mat4_multiply(ui->ortho, view, ui->mvp);
     86 	bind_uniforms(ui->shader, structures, ARRAY_SIZE(structures));
     87 	check_gl();
     88 	
     89 	// render quad
     90 	render_geometry(get_geometry(&ui->quad_geom_id), ui->shader);
     91 	check_gl();
     92 }
     93 
     94 
     95 void resize_ui(struct ui *ui, int width, int height) {
     96     float left = 0.0;
     97     float right = 1.0;
     98     float bottom = 0.0;
     99     float top = 1.0;
    100     float near = -1.0;
    101     float far = 2.0;
    102 
    103     mat4_ortho(left, right, bottom, top, near, far, ui->ortho);
    104 }
    105 
    106 void create_ui(struct ui *ui, int width, int height, struct gpu_program *shader) {
    107     struct shader vertex;
    108     struct shader fragment;
    109     int ok = 0;
    110     // TODO: handle runtime ui errors (there shouldn't be any...)
    111     (void)ok;
    112 
    113     ui->shader = shader;
    114     create_quad(&ui->quad_geom_id);
    115     check_gl();
    116 
    117     ok = make_shader(GL_VERTEX_SHADER, SHADER("ui.v.glsl"), &vertex);
    118     assert(ok && "ui vertex shader");
    119 
    120     ok = make_shader(GL_FRAGMENT_SHADER, SHADER("ui.f.glsl"), &fragment);
    121     assert(ok && "ui fragment shader");
    122 
    123     ok = make_program("ui", &vertex, &fragment, ui->shader, ui_bindings,
    124 		    ARRAY_SIZE(ui_bindings));
    125     assert(ok && "ui program");
    126 
    127     check_gl();
    128     resize_ui(ui, width, height);
    129     check_gl();
    130 }