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#include "imm_renderer_impl.h"
#include <gfx/render_backend.h>
#include <gfx/util/shader.h>
#include <math/aabb3.h>
#include <assert.h>
#include <string.h> // memcpy
bool imm_renderer_make(ImmRenderer* renderer, RenderBackend* render_backend) {
assert(renderer);
assert(render_backend);
const size_t num_triangle_verts = IMM_MAX_NUM_TRIANGLES * 3;
renderer->render_backend = render_backend;
renderer->triangles = gfx_make_geometry(
render_backend,
&(GeometryDesc){
.type = Triangles,
.buffer_usage = BufferDynamic,
.num_verts = num_triangle_verts,
.positions3d =
(BufferView3d){.size_bytes = num_triangle_verts * sizeof(vec3)}});
if (!renderer->triangles) {
goto cleanup;
}
renderer->shader = gfx_make_immediate_mode_shader(render_backend);
if (!renderer->shader) {
goto cleanup;
}
renderer->matrix_stack[0] = mat4_id();
renderer->stack_pointer = 0;
gfx_imm_set_colour(renderer, vec4_make(0.0, 0.0, 0.0, 1.0));
return true;
cleanup:
imm_renderer_destroy(renderer);
return false;
}
void imm_renderer_destroy(ImmRenderer* renderer) {
assert(renderer);
assert(renderer->render_backend);
if (renderer->triangles) {
gfx_destroy_geometry(renderer->render_backend, &renderer->triangles);
// TODO: Could also destroy the geometry's buffers here.
}
if (renderer->shader) {
gfx_destroy_shader_program(renderer->render_backend, &renderer->shader);
}
}
void imm_renderer_flush(ImmRenderer* renderer) {
assert(renderer);
if (renderer->num_triangle_verts > 0) {
gfx_update_geometry(
renderer->triangles,
&(GeometryDesc){
.num_verts = renderer->num_triangle_verts,
.positions3d = (BufferView3d){
.data = renderer->triangle_verts,
.size_bytes = renderer->num_triangle_verts * sizeof(vec3)}
});
gfx_apply_uniforms(renderer->shader);
gfx_render_geometry(renderer->triangles);
renderer->num_triangle_verts = 0;
}
}
void gfx_imm_start(ImmRenderer* renderer) {
assert(renderer);
// Shader uniforms are applied lazily.
// TODO: In the event that gfx_activate_shader_program() activates uniforms
// automatically for convenience, call an overload here that doesn't do so.
ShaderProgram* shader = renderer->shader;
gfx_activate_shader_program(shader);
}
void gfx_imm_end(ImmRenderer* renderer) {
assert(renderer);
imm_renderer_flush(renderer);
gfx_deactivate_shader_program(renderer->shader);
}
void gfx_imm_draw_triangles(
ImmRenderer* renderer, const vec3 verts[], size_t num_triangles) {
assert(renderer);
assert(verts);
const size_t new_verts = num_triangles * 3;
assert(
renderer->num_triangle_verts + new_verts < (IMM_MAX_NUM_TRIANGLES * 3));
memcpy(
renderer->triangle_verts + renderer->num_triangle_verts, verts,
new_verts * sizeof(vec3));
renderer->num_triangle_verts += new_verts;
}
void gfx_imm_draw_triangle(ImmRenderer* renderer, const vec3 verts[3]) {
gfx_imm_draw_triangles(renderer, verts, 1);
}
void gfx_imm_draw_aabb2(ImmRenderer* renderer, aabb2 box) {
assert(renderer);
// clang-format off
const vec3 verts[4] = {
vec3_make(box.min.x, box.min.y, 0), // 3 ---- 2
vec3_make(box.max.x, box.min.y, 0), // | |
vec3_make(box.max.x, box.max.y, 0), // | |
vec3_make(box.min.x, box.max.y, 0)}; // 0 ---- 1
// clang-format on
#define tri(i0, i1, i2) verts[i0], verts[i1], verts[i2]
const vec3 tris[6] = {tri(0, 1, 2), tri(0, 2, 3)};
#undef tri
gfx_imm_draw_triangles(renderer, tris, 2);
}
void gfx_imm_draw_aabb3(ImmRenderer* renderer, aabb3 box) {
assert(renderer);
// clang-format off
const vec3 vertices[8] = {
vec3_make(box.min.x, box.min.y, box.max.z), // 7 ----- 6
vec3_make(box.max.x, box.min.y, box.max.z), // / /|
vec3_make(box.max.x, box.max.y, box.max.z), // 3 ----- 2 |
vec3_make(box.min.x, box.max.y, box.max.z), // | | |
vec3_make(box.min.x, box.min.y, box.min.z), // | 4 ----- 5
vec3_make(box.max.x, box.min.y, box.min.z), // |/ |/
vec3_make(box.max.x, box.max.y, box.min.z), // 0 ----- 1
vec3_make(box.min.x, box.max.y, box.min.z)};
// clang-format on
gfx_imm_draw_box3(renderer, vertices);
}
void gfx_imm_draw_box3(ImmRenderer* renderer, const vec3 vertices[8]) {
assert(renderer);
assert(vertices);
// 7 ----- 6
// / /|
// 3 ----- 2 |
// | | |
// | 4 ----- 5
// |/ |/
// 0 ----- 1
#define tri(i0, i1, i2) vertices[i0], vertices[i1], vertices[i2]
const vec3 tris[36] = {// Front.
tri(0, 1, 2), tri(0, 2, 3),
// Right.
tri(1, 5, 6), tri(1, 6, 2),
// Back.
tri(5, 4, 7), tri(5, 7, 6),
// Left.
tri(4, 0, 03), tri(4, 3, 7),
// Top.
tri(3, 2, 6), tri(3, 6, 7),
// Bottom.
tri(0, 4, 5), tri(0, 5, 1)};
gfx_imm_draw_triangles(renderer, tris, 12);
}
// Load the top of the matrix stack into the shader.
static void update_shader_model_matrix(ImmRenderer* renderer) {
assert(renderer);
imm_renderer_flush(renderer);
gfx_set_mat4_uniform(
renderer->shader, "Model",
&renderer->matrix_stack[renderer->stack_pointer]);
}
void gfx_imm_load_identity(ImmRenderer* renderer) {
assert(renderer);
renderer->matrix_stack[0] = mat4_id();
renderer->stack_pointer = 0;
update_shader_model_matrix(renderer);
}
void gfx_imm_push_matrix(ImmRenderer* renderer, const mat4* matrix) {
assert(renderer);
assert(matrix);
assert(renderer->stack_pointer >= 0);
assert(renderer->stack_pointer < IMM_MAX_NUM_MATRICES); // TODO: hard assert.
renderer->matrix_stack[renderer->stack_pointer + 1] =
mat4_mul(*matrix, renderer->matrix_stack[renderer->stack_pointer]);
renderer->stack_pointer += 1;
update_shader_model_matrix(renderer);
}
void gfx_imm_pop_matrix(ImmRenderer* renderer) {
assert(renderer);
assert(renderer->stack_pointer > 0); // TODO: hard assert.
// For debugging, zero out the matrix stack as matrices are popped out.
memset(
&renderer->matrix_stack[renderer->stack_pointer], 0,
sizeof(renderer->matrix_stack[0]));
renderer->stack_pointer -= 1;
update_shader_model_matrix(renderer);
}
void gfx_imm_translate(ImmRenderer* renderer, vec3 offset) {
assert(renderer);
const mat4 mat = mat4_translate(offset);
gfx_imm_push_matrix(renderer, &mat);
}
void gfx_imm_set_camera(ImmRenderer* renderer, const Camera* camera) {
assert(renderer);
assert(renderer->shader);
imm_renderer_flush(renderer);
const mat4 view = spatial3_inverse_transform(&camera->spatial);
const mat4 view_proj = mat4_mul(camera->projection, view);
gfx_imm_set_view_projection_matrix(renderer, &view_proj);
}
void gfx_imm_set_model_matrix(ImmRenderer* renderer, const mat4* model) {
assert(renderer);
assert(model);
imm_renderer_flush(renderer);
renderer->matrix_stack[0] = *model;
renderer->stack_pointer = 0;
update_shader_model_matrix(renderer);
}
void gfx_imm_set_view_projection_matrix(
ImmRenderer* renderer, const mat4* view_proj) {
assert(renderer);
assert(renderer->shader);
imm_renderer_flush(renderer);
gfx_set_mat4_uniform(renderer->shader, "ViewProjection", view_proj);
}
void gfx_imm_set_colour(ImmRenderer* renderer, vec4 colour) {
assert(renderer);
assert(renderer->shader);
imm_renderer_flush(renderer);
gfx_set_vec4_uniform(renderer->shader, "Colour", colour);
}
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