SWR_FN void swr_render_model(swr_render_target *target, u32 render_mode, model *model, vec3 cam_pos,
mat4 model_mat, mat4 viewproj_mat, mat4 screen_mat, vec3 sun_direction,
col4 sun_col, float ambient_intencity, mem_pool *pool) {
tex2d target_tex = *target->texture;
float *z_buffer = target->z_buffer;
u8 *old_hi_ptr = pool->hi;
vec4 *vertices = (vec4 *)mem_push_back(pool, model->nvertices * sizeof(*vertices));
vec3 *cam_directions = (vec3 *)mem_push_back(pool, model->nvertices * sizeof(*cam_directions));
for (u32 i = 0, e = model->nvertices; i < e; ++i) {
vec3 v = mul_m4v4(model_mat, v3_to_v4(model->vertices[i], 1.0f)).xyz;
cam_directions[i] = norm_v3(sub_v3(v, cam_pos));
vertices[i] = mul_m4v4(viewproj_mat, v3_to_v4(v, 1.0f));
}
face **culled_faces = (face **)mem_push_back(pool, model->nface_groups * sizeof(*culled_faces));
u32 *nculled_faces = (u32 *)mem_push_back(pool, model->nface_groups * sizeof(*nculled_faces));
for (u32 face_group = 0; face_group < model->nface_groups; ++face_group) {
face *src_faces = model->face_groups[face_group].faces;
u32 nsrc_faces = model->face_groups[face_group].nfaces;
face *faces = culled_faces[face_group] =
(face *)mem_push_back(pool, nsrc_faces * sizeof(*faces));
u32 nfaces = 0;
for (u32 i = 0; i < nsrc_faces; ++i) {
face face = src_faces[i];
b32 inside_frustrum = true;
for (u32 j = 0; j < 3; ++j) {
vec4 vertex = vertices[face.v[j]];
if (vertex.x > vertex.w || vertex.x < -vertex.w || vertex.y > vertex.w ||
vertex.y < -vertex.w || vertex.z > vertex.w || vertex.z < -vertex.w ||
vertex.w == 0) {
inside_frustrum = false;
break;
}
}
if (inside_frustrum)
faces[nfaces++] = face;
}
nculled_faces[face_group] = nfaces;
}
// TODO: avoid computing irrelevant data (?)
for (u32 i = 0; i < model->nvertices; ++i) {
vec4 vertex = vertices[i];
vertex = div_v4f(vertex, vertex.w);
vertex = mul_m4v4(screen_mat, vertex);
vertices[i] = vertex;
}
for (u32 face_group = 0; face_group < model->nface_groups; ++face_group) {
face *faces = culled_faces[face_group];
u32 nfaces = nculled_faces[face_group];
material *material = model->face_groups[face_group].material;
for (u32 i = 0; i < nfaces; ++i) {
face face = faces[i];
vec4 verts[] = {vertices[face.v[0]], vertices[face.v[1]], vertices[face.v[2]]};
u32 x1 = (u32)verts[0].x;
u32 y1 = (u32)verts[0].y;
u32 x2 = (u32)verts[1].x;
u32 y2 = (u32)verts[1].y;
u32 x3 = (u32)verts[2].x;
u32 y3 = (u32)verts[2].y;
if (render_mode & (SRM_SHADED | SRM_TEXTURED)) {
u32 minX = minu(x1, minu(x2, x3));
u32 minY = minu(y1, minu(y2, y3));
u32 maxX = maxu(x1, maxu(x2, x3)) + 1;
u32 maxY = maxu(y1, maxu(y2, y3)) + 1;
vec3 norms[3];
float lum[3];
if (render_mode & SRM_SHADED) {
// TODO: apply reverse transformations to normales
norms[0] = model->normales[face.n[0]];
norms[1] = model->normales[face.n[1]];
norms[2] = model->normales[face.n[2]];
float diffuse[3];
for (u32 j = 0; j < 3; ++j)
diffuse[j] = clamp(dot_v3(norms[j], sun_direction), 0, 1.0f);
vec3 L = neg_v3(sun_direction);
float specular[3] = {0};
for (u32 j = 0; j < 3; ++j) {
if (diffuse[j]) {
vec3 V = cam_directions[face.v[j]];
vec3 H = norm_v3(add_v3(V, L));
specular[j] = (float)pow(dot_v3(H, norms[j]), 32);
}
}
for (u32 j = 0; j < 3; ++j)
lum[j] = ambient_intencity + diffuse[j] + specular[j];
}
vec2 face_uvs[3];
face_uvs[0] = model->uvs[face.uv[0]];
face_uvs[1] = model->uvs[face.uv[1]];
face_uvs[2] = model->uvs[face.uv[2]];
vec2 a = {(float)x1, (float)y1};
vec2 b = {(float)x2, (float)y2};
vec2 c = {(float)x3, (float)y3};
vec2 v0 = sub_v2(b, a);
vec2 v1 = sub_v2(c, a);
for (u32 x = minX; x < maxX; ++x) {
for (u32 y = minY; y < maxY; ++y) {
// calculate barycentric coords...
vec2 p = {(float)x, (float)y};
vec2 v2 = sub_v2(p, a);
float d00 = dot_v2(v0, v0);
float d01 = dot_v2(v0, v1);
float d11 = dot_v2(v1, v1);
float d20 = dot_v2(v2, v0);
float d21 = dot_v2(v2, v1);
float denom = d00 * d11 - d01 * d01;
float v = (d11 * d20 - d01 * d21) / denom;
float w = (d00 * d21 - d01 * d20) / denom;
float u = 1.0f - v - w;
if (!(v >= -0.001 && w >= -0.001 && u >= -0.001))
continue;
u32 z_buff_idx = y * target_tex.width + x;
float z = verts[1].z * v + verts[2].z * w + verts[0].z * u;
if (z_buffer[z_buff_idx] > z) {
float l = 1.0f;
if (render_mode & SRM_SHADED) {
l = lum[1] * v + lum[2] * w + lum[0] * u;
}
col4 texel = {255, 255, 255, 255};
if ((render_mode & SRM_TEXTURED) && material->diffuse) {
float tu =
face_uvs[1].x * v + face_uvs[2].x * w + face_uvs[0].x * u;
float tv =
face_uvs[1].y * v + face_uvs[2].y * w + face_uvs[0].y * u;
tu *= material->diffuse->width;
tv *= material->diffuse->height;
texel = *sample_t2d(*material->diffuse, (u32)tu, (u32)tv);
}
col4 fragment_col = { .e[3] = 255 };
for (u32 j = 0; j < 3; ++j) {
float cl = sun_col.e[j] * l / 255.0f;
fragment_col.e[j] = (u8)clamp(texel.e[j] * cl, 0, 255.0f);
}
*sample_t2d(target_tex, x, y) = fragment_col;
z_buffer[z_buff_idx] = z;
}
}
}
}
}
if (render_mode & SRM_WIREFRAME) {
for (u32 i = 0; i < nfaces; ++i) {
const col4 model_col = {255, 255, 255, 255};
vec4 v1 = vertices[faces[i].v[0]];
vec4 v2 = vertices[faces[i].v[1]];
vec4 v3 = vertices[faces[i].v[2]];
s32 x1 = (s32)v1.x;
s32 y1 = (s32)v1.y;
s32 x2 = (s32)v2.x;
s32 y2 = (s32)v2.y;
s32 x3 = (s32)v3.x;
s32 y3 = (s32)v3.y;
swr_line(x1, y1, x2, y2, model_col, target_tex);
swr_line(x2, y2, x3, y3, model_col, target_tex);
swr_line(x3, y3, x1, y1, model_col, target_tex);
}
}
}
int main(void)
{
if(!glfwInit()) {
printf("Could not init GLFW");
getchar();
return -1;
}
glfwWindowHint(GLFW_SAMPLES, 4);
//Opengl 2.1
//glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
//glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
//Opengl 3.3
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // MacOS fix
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
if(window_init(&window, 640, 480, "Test")) {
fprintf( stderr, "Failed to open window.\n" );
getchar();
glfwTerminate();
};
window_set_size_callback(&window, window_size_callback);
glewExperimental = GL_TRUE; // Needed for core profile
if (glewInit() != GLEW_OK) {
fprintf(stderr, "Failed to initialize GLEW\n");
getchar();
glfwTerminate();
return -1;
}
//#clear errors GLEW may trigger
printError();
glClearColor(0.0f, 0.0f, 0.4f, 0.0f);
GLuint VertexArrayID;
glGenVertexArrays(1, &VertexArrayID);
glBindVertexArray(VertexArrayID);
//Load model
//----------
Model cube;
model_init(&cube);
model_set_data_length(&cube, sizeof(cube_vertex_data));
model_set_vertices(&cube, cube_vertex_data);
model_set_colors(&cube, cube_color_data);
model_set_uv_map(&cube, cube_uv_data);
model_set_texture(&cube, "./textures/bricks.dds");
model_bind(&cube);
//Create shaders
//--------------
GLuint vertexShader, fragmentShader;
loadShader(&vertexShader, GL_VERTEX_SHADER, mvpVertexShaderSource);
loadShader(&fragmentShader, GL_FRAGMENT_SHADER, fragmentShaderSource);
//Create program
//--------------
GLuint program;
createProgram(&program, vertexShader, fragmentShader);
// Enable z-buffer
// ---------------
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LESS);
// Enable culling
// --------------
glEnable(GL_CULL_FACE);
// Get MVP uniform
// ---------------
GLuint mvp_ul = glGetUniformLocation(program, "MVP");
// Model Matrix
// ------------
Mat4 s;
scale_m4(&s, 0.1f, 0.1f, 0.1f);
printf("Scale:\n");
print_m4(&s);
Mat4 r;
rotate_m4(&r, 0.0f, 1.0f, 0.0f, 0.0f);
printf("Rotate:\n");
print_m4(&r);
Mat4 t;
translate_m4(&t, 0.0f, 0.0f, 0.0f);
printf("Translate:\n");
print_m4(&t);
Mat4 rs;
printf("Rotated*Scaled:\n");
mul_m4(&rs, &r, &s);
print_m4(&rs);
Mat4 model;
printf("Model:\n");
mul_m4(&model, &t, &rs);
print_m4(&model);
// Camera
// ------
Vec3 pos;
Vec3 center;
Vec3 up;
Vec3 direction;
Vec3 right;
camera_init(&camera);
camera_set_fov(&camera, 1.0f);
camera_set_aspect(&camera, (float)window.width/(float)window.height);
Input input;
input_init(&input, &window, 0.5f, 0.5f, 0.8f, -5.7f, -2.7f);
do {
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glUseProgram(program);
input_get_data(&input, &pos, &direction, &right);
add_v3(¢er, &pos, &direction);
cross_v3(&up, &direction, &right);
camera_set_position(&camera, &pos);
camera_set_center(&camera, ¢er);
camera_set_up(&camera, &up);
// Mvp Matrix
// ----------
Mat4 vp;
camera_get_matrix(&camera, &vp);
Mat4 mvp;
mul_m4(&mvp, &vp, &model);
printf("Perspective:\n");
print_m4(&mvp);
// Set MVP transform
glUniformMatrix4fv(mvp_ul, 1, GL_TRUE, &mvp[0][0]);
model_render(&cube);
window_swap_buffers(&window);
glfwPollEvents();
} while(
glfwGetKey(window.handle, GLFW_KEY_ESCAPE ) != GLFW_PRESS &&
glfwWindowShouldClose(window.handle) == 0
);
// Dispose
// -------
model_dispose(&cube);
glDeleteVertexArrays(1, &VertexArrayID);
glDetachShader(program, fragmentShader);
glDetachShader(program, vertexShader);
glDeleteShader(fragmentShader);
glDeleteShader(vertexShader);
glDeleteProgram(program);
glfwTerminate();
return 0;
}