use crate::gles2::{
gles2_bindings, BufferId, GlContext, ProgramId, RafxTextureGles2, NONE_BUFFER, NONE_PROGRAM,
NONE_TEXTURE,
};
use crate::RafxResult;
use std::ffi::CString;
pub(crate) struct FullscreenQuad {
program_id: ProgramId,
buffer_id: BufferId,
flip_y_buffer_id: BufferId,
}
impl FullscreenQuad {
pub(crate) fn new(gl_context: &GlContext) -> RafxResult<Self> {
let vert_shader_src =
CString::new(include_str!("shaders/fullscreen_quad.vert.gles")).unwrap();
let frag_shader_src =
CString::new(include_str!("shaders/fullscreen_quad.frag.gles")).unwrap();
let vert_shader =
gl_context.compile_shader(gles2_bindings::VERTEX_SHADER, &vert_shader_src)?;
let frag_shader =
gl_context.compile_shader(gles2_bindings::FRAGMENT_SHADER, &frag_shader_src)?;
let program_id = gl_context.gl_create_program()?;
gl_context.gl_attach_shader(program_id, vert_shader)?;
gl_context.gl_attach_shader(program_id, frag_shader)?;
gl_context.gl_bind_attrib_location(program_id, 0, "pos")?;
gl_context.gl_bind_attrib_location(program_id, 1, "uv")?;
gl_context.link_shader_program(program_id)?;
gl_context.gl_destroy_shader(vert_shader)?;
gl_context.gl_destroy_shader(frag_shader)?;
#[rustfmt::skip]
const FLIP_Y_QUAD_VERTICES :[f32; 24] = [
-1.0, 1.0, 0.0, 0.0,
-1.0, -1.0, 0.0, 1.0,
1.0, -1.0, 1.0, 1.0,
-1.0, 1.0, 0.0, 0.0,
1.0, -1.0, 1.0, 1.0,
1.0, 1.0, 1.0, 0.0
];
let flip_y_buffer_id = gl_context.gl_create_buffer()?;
gl_context.gl_bind_buffer(gles2_bindings::ARRAY_BUFFER, flip_y_buffer_id)?;
gl_context.gl_buffer_data(
gles2_bindings::ARRAY_BUFFER,
24 * 4,
FLIP_Y_QUAD_VERTICES.as_ptr() as _,
gles2_bindings::STATIC_DRAW,
)?;
#[rustfmt::skip]
const QUAD_VERTICES :[f32; 24] = [
-1.0, 1.0, 0.0, 1.0,
-1.0, -1.0, 0.0, 0.0,
1.0, -1.0, 1.0, 0.0,
-1.0, 1.0, 0.0, 1.0,
1.0, -1.0, 1.0, 0.0,
1.0, 1.0, 1.0, 1.0
];
let buffer_id = gl_context.gl_create_buffer()?;
gl_context.gl_bind_buffer(gles2_bindings::ARRAY_BUFFER, buffer_id)?;
gl_context.gl_buffer_data(
gles2_bindings::ARRAY_BUFFER,
24 * 4,
QUAD_VERTICES.as_ptr() as _,
gles2_bindings::STATIC_DRAW,
)?;
Ok(FullscreenQuad {
program_id,
buffer_id,
flip_y_buffer_id,
})
}
pub(crate) fn draw(
&self,
gl_context: &GlContext,
texture: &RafxTextureGles2,
flip_y: bool,
) -> RafxResult<()> {
gl_context.gl_disable(gles2_bindings::BLEND)?;
gl_context.gl_disable(gles2_bindings::DEPTH_TEST)?;
gl_context.gl_use_program(self.program_id)?;
let buffer_id = if flip_y {
self.flip_y_buffer_id
} else {
self.buffer_id
};
gl_context.gl_bind_buffer(gles2_bindings::ARRAY_BUFFER, buffer_id)?;
gl_context.gl_vertex_attrib_pointer(0, 2, gles2_bindings::FLOAT, false, 16, 0)?;
gl_context.gl_enable_vertex_attrib_array(0)?;
gl_context.gl_vertex_attrib_pointer(1, 2, gles2_bindings::FLOAT, false, 16, 8)?;
gl_context.gl_enable_vertex_attrib_array(1)?;
gl_context.gl_active_texture(0)?;
gl_context.gl_bind_texture(
gles2_bindings::TEXTURE_2D,
texture.gl_raw_image().gl_texture_id().unwrap(),
)?;
gl_context.gl_tex_parameteri(
gles2_bindings::TEXTURE_2D,
gles2_bindings::TEXTURE_MIN_FILTER,
gles2_bindings::LINEAR as _,
)?;
gl_context.gl_tex_parameteri(
gles2_bindings::TEXTURE_2D,
gles2_bindings::TEXTURE_MAG_FILTER,
gles2_bindings::LINEAR as _,
)?;
gl_context.gl_tex_parameteri(
gles2_bindings::TEXTURE_2D,
gles2_bindings::TEXTURE_WRAP_S,
gles2_bindings::CLAMP_TO_EDGE as _,
)?;
gl_context.gl_tex_parameteri(
gles2_bindings::TEXTURE_2D,
gles2_bindings::TEXTURE_WRAP_T,
gles2_bindings::CLAMP_TO_EDGE as _,
)?;
gl_context.gl_draw_arrays(gles2_bindings::TRIANGLES, 0, 6)?;
gl_context.gl_bind_buffer(gles2_bindings::ARRAY_BUFFER, NONE_BUFFER)?;
gl_context.gl_bind_texture(gles2_bindings::TEXTURE_2D, NONE_TEXTURE)?;
gl_context.gl_use_program(NONE_PROGRAM)?;
gl_context.gl_disable_vertex_attrib_array(0)?;
gl_context.gl_disable_vertex_attrib_array(1)?;
Ok(())
}
pub(crate) fn destroy(
&self,
gl_context: &GlContext,
) -> RafxResult<()> {
gl_context.gl_destroy_program(self.program_id)?;
gl_context.gl_destroy_buffer(self.buffer_id)?;
Ok(())
}
}