/**
* render skybox
*/
void renderWithProgram(GLSL::mat4 &p_pvm_matrix)
{
// CGlStateDisable depth_test(GL_DEPTH_TEST);
CGlErrorCheck();
program.use();
pvm_matrix_uniform.set(p_pvm_matrix);
vertex_buffer.bind();
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, nullptr);
glEnableVertexAttribArray(0);
texture_cube_map.bind();
#if 0
CGlErrorCheck();
glDrawArrays(GL_TRIANGLES, 0, 3);
CGlErrorCheck();
#else
index_buffer.bind();
CGlErrorCheck();
glDrawElements(GL_TRIANGLE_STRIP, 20, GL_UNSIGNED_BYTE, 0);
index_buffer.unbind();
#endif
texture_cube_map.unbind();
glDisableVertexAttribArray(0);
vertex_buffer.unbind();
program.disable();
CGlErrorCheck();
}
/**
* default constructor
*/
CGlDrawFlatCubeMap()
{
program.initVertFragShadersFromDirectory("draw/flat_cube_map");
if (program.error())
{
std::cerr << program.error.getString() << std::endl;
return;
}
program.bindAttribLocation(0, "vertex_position");
program.link();
if (program.error())
{
std::string infoLog;
program.getInfoLog(infoLog);
std::cerr << "info Log: linking: " << infoLog << std::endl;
return;
}
program.bindAttribLocation(0, "vertex_position");
program.bindAttribLocation(1, "vertex_texture_coord");
program.setupUniform(pvm_matrix_uniform, "pvm_matrix");
static const float vertices[4][4] = {
{-1.0, -1.0, 0.0, 1.0},
{ 1.0, -1.0, 0.0, 1.0},
{-1.0, 1.0, 0.0, 1.0},
{ 1.0, 1.0, 0.0, 1.0},
};
const float N = -1;
const float P = 1;
static const float texcoords[6][4][3] = {
{ {P, N, N}, {P, N, P}, {P, P, N}, {P, P, P} }, // X pos
{ {N, N, P}, {N, N, N}, {N, P, P}, {N, P, N} }, // X neg
{ {N, P, N}, {P, P, N}, {N, P, P}, {P, P, P} }, // Y pos
{ {N, N, P}, {P, N, P}, {N, N, N}, {P, N, N} }, // Y neg
{ {P, N, P}, {N, N, P}, {P, P, P}, {N, P, P} }, // Z pos
{ {N, N, N}, {P, N, N}, {N, P, N}, {P, P, N} }, // Z neg
};
vao.bind();
buffer.bind();
buffer.resize(sizeof(vertices)+sizeof(texcoords));
buffer.subData(0, sizeof(vertices), vertices);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
buffer.subData(sizeof(vertices), sizeof(texcoords), texcoords);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)sizeof(vertices));
glEnableVertexAttribArray(1);
vao.unbind();
}
CGlDrawSkyBox() :
vertex_buffer(GL_ARRAY_BUFFER),
index_buffer(GL_ELEMENT_ARRAY_BUFFER),
texture_cube_map(GL_TEXTURE_CUBE_MAP)
{
program.initVertFragShadersFromDirectory("draw/skybox");
CError_AppendReturn(program);
program.link();
if (program.error())
{
std::cerr << "info Log: linking: " << program.getInfoLog() << std::endl;
return;
}
program.setupUniform(pvm_matrix_uniform, "pvm_matrix");
program.use();
program.setUniform1i("sampler_cube", 0);
program.disable();
/**
* initialize buffers
*/
/*
* vertices for cube drawn counterclockwise
* use quads to draw surfaces
*/
#define P +1.0f
#define N -1.0f
static const GLfloat vertices[8][3] = {
{N,N,P},
{N,N,N},
{N,P,P},
{N,P,N},
{P,N,P},
{P,N,N},
{P,P,P},
{P,P,N},
};
#undef N
#undef P
#if 0
static const GLubyte indices[20] = {
#if 0
// faces for counter clockwise triangle strips
4,6,0,2, // front
1,3, // left
5,7, // back
4,6, // right
6, // > ZERO triangle
7,2,3, // top
3,1, // > ZERO triangle
1,5,0,4 // bottom
#else
// faces for clockwise triangle strips
6,4,2,0, // front
3,1, // left
7,5, // back
6,4, // right
4, // > ZERO triangle
5,0,1, // bottom
1,3, // > ZERO triangle
3,7,2,6, // top
#endif
};
#else
static const GLubyte indices[20] = {
#if 0
// faces for counter clockwise triangle strips
4,6,0,2, // front
1,3, // left
5,7, // back
4,6, // right
6, // > ZERO triangle
7,2,3, // top
3,1, // > ZERO triangle
1,5,0,4 // bottom
#else
// faces for clockwise triangle strips
6,4,2,0, // front
3,1, // left
7,5, // back
6,4, // right
4, // > ZERO triangle
5,0,1, // bottom
1,3, // > ZERO triangle
3,7,2,6, // top
#endif
};
#endif
vertex_buffer.bind();
vertex_buffer.data(sizeof(vertices), vertices);
vertex_buffer.unbind();
index_buffer.bind();
index_buffer.data(sizeof(indices), indices);
index_buffer.unbind();
}
/**
* activate usage of program in current program block {}
*/
inline GlProgramUse(GlProgram &p_program)
{
p_program.use();
}
/**
* render flat cube map
*/
void render( CGlCubeMap &cGlCubeMap, ///< handler to cube map
float scale = 1.0f ///< scale flat cube map with this factor
)
{
cGlCubeMap.texture_cube_map.bind();
CGlViewport cGlViewport;
cGlViewport.saveState();
GLSL::mat4 pmv = GLSL::ortho(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
program.use();
pvm_matrix_uniform.set(pmv);
vao.bind();
CGlErrorCheck();
pmv = GLSL::ortho(-1.0f, 1.0f, -1.0f, 1.0f, -1.0f, 1.0f);
// line in texture coordinates (offset = vertices)
#define TEX_LINE(l) (sizeof(GLfloat)*4*4 + (l)*4*3*sizeof(GLfloat))
buffer.bind();
// LEFT
glViewport(0*scale, cGlCubeMap.depth*scale, cGlCubeMap.depth*scale, cGlCubeMap.height*scale);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)TEX_LINE(1));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
// FRONT
glViewport(cGlCubeMap.depth*scale, cGlCubeMap.depth*scale, cGlCubeMap.width*scale, cGlCubeMap.height*scale);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)TEX_LINE(5));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
// RIGHT
glViewport(cGlCubeMap.depth*scale+cGlCubeMap.width*scale, cGlCubeMap.depth*scale, cGlCubeMap.depth*scale, cGlCubeMap.height*scale);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)TEX_LINE(0));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
// BACK
glViewport(cGlCubeMap.depth*2*scale+cGlCubeMap.width*scale, cGlCubeMap.depth*scale, cGlCubeMap.width*scale, cGlCubeMap.height*scale);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)TEX_LINE(4));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
// BOTTOM
glViewport(cGlCubeMap.depth*scale, 0, cGlCubeMap.width*scale, cGlCubeMap.depth*scale);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)TEX_LINE(3));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
// TOP
glViewport(cGlCubeMap.depth*scale, cGlCubeMap.depth*scale + cGlCubeMap.height*scale, cGlCubeMap.width*scale, cGlCubeMap.depth*scale);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, (void*)TEX_LINE(2));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
cGlViewport.restoreState();
vao.unbind();
program.disable();
CGlErrorCheck();
glFlush();
}
