Implemented render of program extents.

docs/todo.txt

@@ -49,5 +49,5 @@ Corner finding
 
 DONE - Show program extents
 
-Render program extents
+DONE - Render program extents
-    - show a blue bounding box for the program extents
+DONE    - show a bounding box for the program extents

render.cpp

@@ -56,6 +56,7 @@ static const char *ps_code = R"(
 
 
 void grbl::program_renderer::render(glm::mat4 mvp, glm::vec2 viewport_size) {
+    // draw model
     shader->bind();
     shader->set_mat4(glm::value_ptr(mvp), "mvp");
     shader->set_vec2(glm::value_ptr(viewport_size), "u_resolution");
@@ -63,7 +64,7 @@ void grbl::program_renderer::render(glm::mat4 mvp, glm::vec2 viewport_size) {
     glBindVertexArray(vao_id);
     glDrawArrays(GL_LINES, 0, vertices_count);
 
-
+    // draw spindle
     auto spindle_xform = glm::translate(glm::mat4(1.0f), spindle_pos);
     auto spindle_view = mvp * spindle_xform;
     shader->set_mat4(glm::value_ptr(spindle_view), "mvp");
@@ -71,6 +72,18 @@ void grbl::program_renderer::render(glm::mat4 mvp, glm::vec2 viewport_size) {
     glBindVertexArray(spindle_vao_id);
     glDrawArrays(GL_LINES, 0, spindle_vertices_count);
 
+    // draw bounding box
+    auto bbox_size = max_pos - min_pos;
+    // need to add proper translation
+
+    auto bbox_translation = glm::translate(glm::mat4(1.0f), {min_pos.x, min_pos.y, min_pos.z});
+    auto bbox_xform = glm::scale(glm::mat4(1.0f), {bbox_size.x, bbox_size.y, bbox_size.z});
+    auto bbox_view = mvp * bbox_translation * bbox_xform;
+    shader->set_mat4(glm::value_ptr(bbox_view), "mvp");
+
+    glBindVertexArray(extents_vao_id);
+    glDrawArrays(GL_LINES, 0, extents_vertices_count);
+
     shader->unbind();
 
     // draw bit location
@@ -78,11 +91,11 @@ void grbl::program_renderer::render(glm::mat4 mvp, glm::vec2 viewport_size) {
 
 void grbl::program_renderer::update(const grbl::program& pgm, const grbl::machine& cnc) {
     if (!initialized) {
-
         shader = new shader_program(vs_code, ps_code);
 
         initialize_spindle_buffers();
         initialize_program_buffers();
+        initialize_extents_buffers();
 
         initialized = true;
     }
@@ -131,6 +144,7 @@ void grbl::program_renderer::initialize_spindle_buffers() {
         float x = sinf((i / (float) cone_granularity) * 2.0f * M_PI);
         float y = cosf((i / (float) cone_granularity) * 2.0f * M_PI);
 
+        // TODO: refactor this to use add_line()
         // from
         buffer_data.push_back(0);
         buffer_data.push_back(0);
@@ -158,6 +172,82 @@ void grbl::program_renderer::initialize_spindle_buffers() {
     spindle_vertices_count = buffer_data.size() * sizeof(float) / sizeOfVertexInBytes;
 }
 
+
+static void add_vertex(std::vector<float>& buffer_data, glm::vec3 v, glm::vec4 col) {
+    buffer_data.push_back(v.x);
+    buffer_data.push_back(v.y);
+    buffer_data.push_back(v.z);
+
+    buffer_data.push_back(col.r);
+    buffer_data.push_back(col.g);
+    buffer_data.push_back(col.b);
+    buffer_data.push_back(col.a);
+}
+
+static void add_line(std::vector<float>& buffer_data, glm::vec3 from, glm::vec3 to, glm::vec4 col) {
+    add_vertex(buffer_data, from, col);
+    add_vertex(buffer_data, to, col);
+}
+
+void grbl::program_renderer::initialize_extents_buffers() {
+    glGenBuffers(1, &extents_vbo_id);
+    glGenVertexArrays(1, &extents_vao_id);
+
+    // vertex format: x, y, z, r, g, b, a
+    // stride: 28 bytes
+    const GLsizei sizeOfVertexInBytes = 28;
+
+    // we're going to draw a simple box for the extents
+    // box is made up of 8 vertices and 12 lines
+
+    glBindVertexArray(extents_vao_id);
+    glBindBuffer(GL_ARRAY_BUFFER, extents_vbo_id);
+
+    glEnableVertexAttribArray(0); // vertices on stream 0
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeOfVertexInBytes, (void *) 0);
+
+    glEnableVertexAttribArray(1); // vertex colors on stream 1
+    glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, sizeOfVertexInBytes, (void *) (sizeof(float) * 3));
+
+    // unbind vao
+    glBindVertexArray(0);
+
+    // we're going to make the box as unit box and scale it when rendering
+    // since we're going to reuse the same box for all loaded programs.
+    // or at least we'll try to.
+
+    // construct box
+    glm::vec4 col(1, 0, 1, 1);
+
+
+    // box will range from [0,0,0] to [1,1,1] and we'll use
+    // translation and scaling afterward if needed to place it
+
+    std::vector<float> buffer_data;
+    // bottom plane
+    add_line(buffer_data, {0, 0, 0}, {1, 0, 0}, col);
+    add_line(buffer_data, {1, 0, 0}, {1, 1, 0}, col);
+    add_line(buffer_data, {1, 1, 0}, {0, 1, 0}, col);
+    add_line(buffer_data, {0, 1, 0}, {0, 0, 0}, col);
+
+    // top plane
+    add_line(buffer_data, {0, 0, 1}, {1, 0, 1}, col);
+    add_line(buffer_data, {1, 0, 1}, {1, 1, 1}, col);
+    add_line(buffer_data, {1, 1, 1}, {0, 1, 1}, col);
+    add_line(buffer_data, {0, 1, 1}, {0, 0, 1}, col);
+
+    // add vertical lines connecting the planes
+    add_line(buffer_data, {0, 0, 0}, {0, 0, 1}, col);
+    add_line(buffer_data, {1, 0, 0}, {1, 0, 1}, col);
+    add_line(buffer_data, {1, 1, 0}, {1, 1, 1}, col);
+    add_line(buffer_data, {0, 1, 0}, {0, 1, 1}, col);
+
+    glBindBuffer(GL_ARRAY_BUFFER, extents_vbo_id);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float) * buffer_data.size(), buffer_data.data(), GL_STATIC_DRAW);
+
+    extents_vertices_count = buffer_data.size() * sizeof(float) / sizeOfVertexInBytes;
+}
+
 void grbl::program_renderer::initialize_program_buffers() {
     glGenBuffers(1, &vbo_id);
     glGenVertexArrays(1, &vao_id);

render.h

@@ -27,16 +27,20 @@ private:
     GLuint vbo_id;
     GLuint vao_id;
 
+    GLuint extents_vbo_id;
+    GLuint extents_vao_id;
+
     std::vector<float> buffer_data;
     shader_program *shader = nullptr;
 
     bool initialized = false;
 
     glm::vec3 min_pos, max_pos, spindle_pos;
-    GLsizei vertices_count, spindle_vertices_count;
+    GLsizei vertices_count, spindle_vertices_count, extents_vertices_count;
 
     void initialize_program_buffers();
     void initialize_spindle_buffers();
+    void initialize_extents_buffers();
 };