void multidrawindirect_app::render(double currentTime)
{
int j;
static const float one = 1.0f;
static const float black[] = { 0.0f, 0.0f, 0.0f, 0.0f };
static double last_time = 0.0;
static double total_time = 0.0;
if (!paused)
total_time += (currentTime - last_time);
last_time = currentTime;
float t = float(total_time);
int i = int(total_time * 3.0f);
glViewport(0, 0, info.windowWidth, info.windowHeight);
glClearBufferfv(GL_COLOR, 0, black);
glClearBufferfv(GL_DEPTH, 0, &one);
const vmath::mat4 view_matrix = vmath::lookat(vmath::vec3(100.0f * cosf(t * 0.023f), 100.0f * cosf(t * 0.023f), 300.0f * sinf(t * 0.037f) - 600.0f),
vmath::vec3(0.0f, 0.0f, 260.0f),
vmath::normalize(vmath::vec3(0.1f - cosf(t * 0.1f) * 0.3f, 1.0f, 0.0f)));
const vmath::mat4 proj_matrix = vmath::perspective(50.0f,
(float)info.windowWidth / (float)info.windowHeight,
1.0f,
2000.0f);
glUseProgram(render_program);
glUniform1f(uniforms.time, t);
glUniformMatrix4fv(uniforms.view_matrix, 1, GL_FALSE, view_matrix);
glUniformMatrix4fv(uniforms.proj_matrix, 1, GL_FALSE, proj_matrix);
glUniformMatrix4fv(uniforms.viewproj_matrix, 1, GL_FALSE, proj_matrix * view_matrix);
glBindVertexArray(object.get_vao());
if (mode == MODE_MULTIDRAW)
{
glMultiDrawArraysIndirect(GL_TRIANGLES, NULL, NUM_DRAWS, 0);
}
else if (mode == MODE_SEPARATE_DRAWS)
{
for (j = 0; j < NUM_DRAWS; j++)
{
GLuint first, count;
object.get_sub_object_info(j % object.get_sub_object_count(), first, count);
glDrawArraysInstancedBaseInstance(GL_TRIANGLES,
first,
count,
1, j);
}
}
}
void multidrawindirect_app::startup()
{
int i;
load_shaders();
object.load("media/objects/asteroids.sbm");
glGenBuffers(1, &indirect_draw_buffer);
glBindBuffer(GL_DRAW_INDIRECT_BUFFER, indirect_draw_buffer);
glBufferData(GL_DRAW_INDIRECT_BUFFER,
NUM_DRAWS * sizeof(DrawArraysIndirectCommand),
NULL,
GL_STATIC_DRAW);
DrawArraysIndirectCommand * cmd = (DrawArraysIndirectCommand *)
glMapBufferRange(GL_DRAW_INDIRECT_BUFFER,
0,
NUM_DRAWS * sizeof(DrawArraysIndirectCommand),
GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT);
for (i = 0; i < NUM_DRAWS; i++)
{
object.get_sub_object_info(i % object.get_sub_object_count(),
cmd[i].first,
cmd[i].count);
cmd[i].primCount = 1;
cmd[i].baseInstance = i;
}
glUnmapBuffer(GL_DRAW_INDIRECT_BUFFER);
glBindVertexArray(object.get_vao());
glGenBuffers(1, &draw_index_buffer);
glBindBuffer(GL_ARRAY_BUFFER, draw_index_buffer);
glBufferData(GL_ARRAY_BUFFER,
NUM_DRAWS * sizeof(GLuint),
NULL,
GL_STATIC_DRAW);
GLuint * draw_index =
(GLuint *)glMapBufferRange(GL_ARRAY_BUFFER,
0,
NUM_DRAWS * sizeof(GLuint),
GL_MAP_WRITE_BIT |
GL_MAP_INVALIDATE_BUFFER_BIT);
for (i = 0; i < NUM_DRAWS; i++)
{
draw_index[i] = i;
}
glUnmapBuffer(GL_ARRAY_BUFFER);
glVertexAttribIPointer(10, 1, GL_UNSIGNED_INT, 0, NULL);
glVertexAttribDivisor(10, 1);
glEnableVertexAttribArray(10);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glEnable(GL_CULL_FACE);
}