I wish to render a full screen quad but nothing is showing.

------------------------------------------------------------------

geometry shader:

#version 330 core

layout(points) in;
layout(triangle_strip, max_vertices = 4) out;

out vec2 texcoord;

void main()
{
gl_Position = vec4( 1.0, 1.0, 0.5, 1.0 );
texcoord = vec2( 1.0, 1.0 );
EmitVertex();

gl_Position = vec4(-1.0, 1.0, 0.5, 1.0 );
texcoord = vec2( 0.0, 1.0 );
EmitVertex();

gl_Position = vec4( 1.0,-1.0, 0.5, 1.0 );
texcoord = vec2( 1.0, 0.0 );
EmitVertex();

gl_Position = vec4(-1.0,-1.0, 0.5, 1.0 );
texcoord = vec2( 0.0, 0.0 );
EmitVertex();

EndPrimitive();
}

--------------------------------------------------------------------------

fragment shader

#version 330

out vec4 outputColor;

void main()
{
outputColor = vec4(1,0,1,1);
}

-----------------------------------------------------------------------

vertex shader

#version 330 core

void main()
{

}

------------------------------------------------

I render with:

glDrawArrays(GL_POINTS, 0, 1);

What am I doing wrong?

Thanks.

Solved:

void RenderScene(Shader &shader)
{
// Room cube
glm::mat4 model;
model = glm::scale(model, glm::vec3(10.0));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
glDisable(GL_CULL_FACE); // Note that we disable culling here since we render 'inside' the cube instead of the usual 'outside' which throws off the normal culling methods.
glUniform1i(glGetUniformLocation(shader.Program, "reverse_normals"), 1); // A small little hack to invert normals when drawing cube from the inside so lighting still works.
RenderCube();
glUniform1i(glGetUniformLocation(shader.Program, "reverse_normals"), 0); // And of course disable it
glEnable(GL_CULL_FACE);
// Cubes
model = glm::mat4();
model = glm::translate(model, glm::vec3(4.0f, -3.5f, 0.0));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
RenderCube();
model = glm::mat4();
model = glm::translate(model, glm::vec3(2.0f, 3.0f, 1.0));
model = glm::scale(model, glm::vec3(1.5));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
RenderCube();
model = glm::mat4();
model = glm::translate(model, glm::vec3(-3.0f, -1.0f, 0.0));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
RenderCube();
model = glm::mat4();
model = glm::translate(model, glm::vec3(-1.5f, 1.0f, 1.5));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
RenderCube();
model = glm::mat4();
model = glm::translate(model, glm::vec3(-1.5f, 2.0f, -3.0));
model = glm::rotate(model, 60.0f, glm::normalize(glm::vec3(1.0, 0.0, 1.0)));
model = glm::scale(model, glm::vec3(1.5));
glUniformMatrix4fv(glGetUniformLocation(shader.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
RenderCube();
}
// RenderQuad() Renders a 1x1 quad in NDC, best used for framebuffer color targets
// and post-processing effects.
GLuint quadVAO = 0;
GLuint quadVBO;
void RenderQuad()
{
if (quadVAO == 0)
{
GLfloat quadVertices[] = {
// Positions // Texture Coords
-1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
-1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
};
// Setup plane VAO
glGenVertexArrays(1, &quadVAO);
glGenBuffers(1, &quadVBO);
glBindVertexArray(quadVAO);
glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
}
glBindVertexArray(quadVAO);

glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindVertexArray(0);
}