DI-Guy Graphics API, diguyOglGraphicsShape

diguyOglGraphicsShape.cpp

DI-Guy API Version 12.5.1

This file was automatically generated from diguyOglGraphicsShape.cpp. Do not edit this file directly; the changes will be lost.

Shapes are the high-level containers of visible geometry. They are attached to links, and contain zero or more mesh objects.

The class diguyOglGraphicsShape is an example of a diguyGraphicsShape subclass for an immediate mode renderer using the DI-Guy Loader. The example subclass shows how to use the accessors of the diguyGraphicsShape class and which virtual functions should be overridden for an immediate mode renderer such as OpenGL.

#include "diguyOglGraphicsShape.h" #include "ogl_headers.h" #include <stdlib.h> #include <diguyApp.h> #include <diguyGraphicsShaderProgram.h> #include <diguyGraphicsTexture.h> GLuint diguyOglGraphicsShape::sm_default_variation_texture_object = 0;

Initialize data members of the class to a known state.

Base class data will not be fully initialized until the Build Stage is done, so base class accessors should not be called here.

diguyOglGraphicsShape::diguyOglGraphicsShape(void* internal_data)     :     diguyGraphicsShape(internal_data),     m_display_list(0),     m_unique_texture_object(0) {     /*      * Nothing else to do after calling base class constructor and      * initializing data members.      */ }

Build Stage

Description:

Override of diguyGraphicsShape::build().

The build() function should create the necessary objects that will apply offset data of this shape from its parent link during the Draw Stage.

This implementation checks to see if this shape has any offsets from its link. If so, it defines a display list that will apply the offsets each time the shape is drawn. Shape offsets are always static, so they can safely be encoded in a display list. Note that no visible geometry is built. This will be done when the mesh objects attached to this shape have their build() functions called.

No display list is created if this shape has no offsets.

void diguyOglGraphicsShape::build() {     if (get_has_offset_translation() ||         get_has_offset_rotation() ||         get_has_offset_scale())     {         m_display_list = glGenLists(1);         if (m_display_list == 0)             return;         /*          * Compile the transformations into m_display_list.          */         glNewList(m_display_list, GL_COMPILE);         {             if (get_has_offset_translation())             {                 float offset_translation[3];                 get_offset_translation(&offset_translation[0],                     &offset_translation[1],                     &offset_translation[2]);                 if ((offset_translation[0] != 0.0f) ||                     (offset_translation[1] != 0.0f) ||                     (offset_translation[2] != 0.0f))                 {                     glTranslatef(offset_translation[0],                      offset_translation[1],                      offset_translation[2]);                 }             }             if (get_has_offset_rotation())             {                 float offset_rotation [3];                 get_offset_rotation (&offset_rotation [0],                     &offset_rotation [1],                     &offset_rotation [2]);                 if (offset_rotation [0] != 0.0f)                     glRotatef(offset_rotation [0], 0.0, 0.0, 1.0);                 if (offset_rotation [1] != 0.0f)                     glRotatef(offset_rotation [1], 1.0, 0.0, 0.0);                 if (offset_rotation [2] != 0.0f)                     glRotatef(offset_rotation [2], 0.0, 1.0, 0.0);             }             if (get_has_offset_scale())             {                 float offset_scale[3];                 get_offset_scale(&offset_scale[0],                     &offset_scale[1],                     &offset_scale[2]);                 if ((offset_scale[0] != 1.0f) ||                     (offset_scale[1] != 1.0f) ||                     (offset_scale[2] != 1.0f))                 {                     glScalef(offset_scale[0],                      offset_scale[1],                      offset_scale[2]);                 }             }         }         glEndList();     } }

Unbuild Stage

Description:

Override of diguyGraphicsShape::unbuild().

The unbuild() function should destroy the objects created in the build() function.

This implementation destroys the display list created in the build() function.

void diguyOglGraphicsShape::unbuild() {     if (m_display_list != 0)         glDeleteLists(m_display_list, 1);     m_display_list = 0;     if(m_unique_texture_object){         glDeleteTextures(1, &m_unique_texture_object);     }     m_unique_texture_object = 0; }

Draw Stage

Description:

Override of diguyGraphicsShape::draw().

The draw() function needs to apply offsets created in the Build Stage so that subsequent drawing of child meshes will be correctly placed.

This implementation applies the display list created in the Build Stage. This will change the OpenGL matrix stack to include this shape's offsets, which will change the position and orientation of meshes attached to this shape.

For this immediate mode example all of the visible geometry is in mesh objects attached to this shape, so the lod argument isn't needed.

void diguyOglGraphicsShape::draw(int lod) {     if (m_display_list != 0)         glCallList(m_display_list);     /*      * If this is a render pass for finding intersections, look up and apply      * the unique color of this shape.      */     if (diguyApp::get_app()->get_render_pass_flags() & DIGUY_RENDER_PASS_INTERSECTION)     {         unsigned char r, g, b;         get_unique_color(&r, &g, &b);         glColor3ub(r, g, b);     }     /*      * If this shader support the variation texture system bind either the degenerate texture      * or the unique one.      */     diguyGraphicsShaderProgram * shader = diguyApp::get_app()->get_current_bound_shader_program();     if(shader && shader->get_textures_used_bitmask() & DIGUY_TEXTURE_MAP_MASK_COMPONENTS)     {         if (glActiveTexture){             glActiveTexture(GL_TEXTURE0 + DIGUY_TEXTURE_MAP_TYPE_COMPONENT_RAMP);         }         if(m_unique_texture_object)         {             glBindTexture(GL_TEXTURE_2D, m_unique_texture_object);         }         else{             if(sm_default_variation_texture_object == 0){                 create_default_variation_texture();             }             glBindTexture(GL_TEXTURE_2D, sm_default_variation_texture_object);              }     } }

void diguyOglGraphicsShape::update_variation_texture(int num_pixels, unsigned char * pixel_data) {     /*      * Override from the base class. Send a unique texture to the graphics card.      */     if(m_unique_texture_object == 0){         glGenTextures(1, &m_unique_texture_object);     }     glBindTexture(GL_TEXTURE_2D, m_unique_texture_object);     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, num_pixels, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixel_data);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);     glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);     glGenerateMipmapEXT(GL_TEXTURE_2D);     glBindTexture(GL_TEXTURE_2D, 0); }

void diguyOglGraphicsShape::create_default_variation_texture() {     /*      * If there's no variation texture and we're using a variation based shader      * create one as a place holder.      */     if(sm_default_variation_texture_object == 0){         glGenTextures(1, &sm_default_variation_texture_object );     }     glBindTexture(GL_TEXTURE_2D, sm_default_variation_texture_object );     unsigned char buf[] = {128, 128, 128, 255};     glTexImage2D(GL_TEXTURE_2D, 0, 4, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, buf);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);     glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);     glGenerateMipmapEXT(GL_TEXTURE_2D);     glBindTexture(GL_TEXTURE_2D, 0); }

Create and return an object of a subclass of diguyGraphicsShape. This function will be called whenever DI-Guy requires a shape object.

diguyGraphicsShape* diguyOglGraphicsShape_create_func(void* internal_data) {     return new diguyOglGraphicsShape(internal_data); }