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LEFTONE/util/glyphas/drawer.c

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#include "./drawer.h"
#include <assert.h>
#include <stddef.h>
#include <GL/glew.h>
#include "util/gleasy/buffer.h"
#include "util/gleasy/texture.h"
#include "util/gleasy/program.h"
#include "util/math/vector.h"
#include "./block.h"
/* resources */
#include "util/glyphas/anysrc/drawer.vshader.h"
#include "util/glyphas/anysrc/drawer.fshader.h"
#define UNIFORM_TEX_ 0
#define VSHADER_IN_POS_ 0
#define VSHADER_IN_SIZE_ 1
#define VSHADER_IN_UV_POS_ 2
#define VSHADER_IN_UV_SIZE_ 3
#define VSHADER_IN_COLOR_ 4
#pragma pack(push, 1)
typedef struct {
vec2_t pos;
vec2_t size;
vec2_t uv_pos;
vec2_t uv_size;
vec4_t color;
} glyphas_drawer_instance_t;
#pragma pack(pop)
gleasy_program_t glyphas_drawer_create_default_program(void) {
return gleasy_program_new("", 0,
glyphas_drawer_vshader_, sizeof(glyphas_drawer_vshader_),
glyphas_drawer_fshader_, sizeof(glyphas_drawer_fshader_));
}
void glyphas_drawer_initialize(
glyphas_drawer_t* drawer, gleasy_texture_2d_t tex) {
assert(drawer != NULL);
*drawer = (typeof(*drawer)) {
.tex = tex,
};
glCreateVertexArrays(1, &drawer->vao);
glGenBuffers(1, &drawer->instances);
glBindVertexArray(drawer->vao);
glBindBuffer(GL_ARRAY_BUFFER, drawer->instances);
# define enable_(index, var, dim, type) do { \
glEnableVertexAttribArray(index); \
glVertexAttribPointer( \
index, dim, type, GL_FALSE, \
sizeof(glyphas_drawer_instance_t), \
NULL + offsetof(glyphas_drawer_instance_t, var)); \
glVertexAttribDivisor(index, 1); \
} while (0)
enable_(VSHADER_IN_POS_, pos, 2, GL_FLOAT);
enable_(VSHADER_IN_SIZE_, size, 2, GL_FLOAT);
enable_(VSHADER_IN_UV_POS_, uv_pos, 2, GL_FLOAT);
enable_(VSHADER_IN_UV_SIZE_, uv_size, 2, GL_FLOAT);
enable_(VSHADER_IN_COLOR_, color, 4, GL_FLOAT);
# undef enable_attrib_
}
void glyphas_drawer_deinitialize(glyphas_drawer_t* drawer) {
assert(drawer != NULL);
glDeleteBuffers(1, &drawer->instances);
glDeleteVertexArrays(1, &drawer->vao);
}
void glyphas_drawer_clear(glyphas_drawer_t* drawer, size_t reserve) {
assert(drawer != NULL);
assert(reserve > 0);
drawer->instances_length = 0;
if (drawer->instances_reserved < reserve) {
glBindBuffer(GL_ARRAY_BUFFER, drawer->instances);
glBufferData(GL_ARRAY_BUFFER,
reserve*sizeof(glyphas_drawer_instance_t), NULL, GL_DYNAMIC_DRAW);
drawer->instances_reserved = reserve;
}
}
void glyphas_drawer_add_block(
glyphas_drawer_t* drawer, const glyphas_block_t* block) {
assert(drawer != NULL);
assert(block != NULL);
size_t len;
const glyphas_block_item_t* items = glyphas_block_get_items(block, &len);
for (size_t i = 0; i < len; ++i) {
glyphas_drawer_add_block_item(drawer, &items[i]);
}
}
void glyphas_drawer_add_block_item(
glyphas_drawer_t* drawer, const glyphas_block_item_t* item) {
assert(drawer != NULL);
assert(item != NULL);
const glyphas_drawer_instance_t insta = {
.pos = item->pos,
.size = item->size,
.uv_pos = vec2(item->uv.left, item->uv.top),
.uv_size = vec2(item->uv.right-item->uv.left, item->uv.top-item->uv.bottom),
.color = item->color,
};
const size_t offset = drawer->instances_length * sizeof(insta);
glBindBuffer(GL_ARRAY_BUFFER, drawer->instances);
glBufferSubData(GL_ARRAY_BUFFER, offset, sizeof(insta), &insta);
++drawer->instances_length;
}
void glyphas_drawer_draw(const glyphas_drawer_t* drawer) {
assert(drawer != NULL);
if (drawer->instances_length == 0) return;
glBindVertexArray(drawer->vao);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, drawer->tex);
glUniform1i(UNIFORM_TEX_, 0);
glDrawArraysInstanced(GL_TRIANGLES, 0, 6, drawer->instances_length);
}