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opengl moment #1

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veclavtalica merged 27 commits from opengl into main 2024-07-28 14:50:35 +00:00
Conversation 0 Commits 27 Files Changed 32 +142 -122
3 changed files with 142 additions and 122 deletions
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22
src/private/rendering.h
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@ -20,28 +20,6 @@ struct sprite_primitive {
bool blend; /* must be explicitly stated, textures having alpha channel isn't enough */
};
/* interleaved vertex array data */
/* TODO: use int16_t for uvs */
/* TODO: int16_t could be used for positioning, but we would need to have more CPU calcs */
struct sprite_primitive_payload {
/* upper-left */
t_fvec2 v0;
t_fvec2 uv0;
t_color c0;
/* bottom-left */
t_fvec2 v1;
t_fvec2 uv1;
t_color c1;
/* bottom-right */
t_fvec2 v2;
t_fvec2 uv2;
t_color c2;
/* upper-right */
t_fvec2 v3;
t_fvec2 uv3;
t_color c3;
};
struct rect_primitive {
t_frect rect;
t_color color;

13
src/rendering.c
View File

@ -88,18 +88,7 @@ static void render_2d(void) {
glDepthRange((double)batch_count / UINT16_MAX, 1.0);
if (batch.blend) {
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDepthFunc(GL_ALWAYS);
render_sprites(current, batch.size, false);
} else {
glDisable(GL_BLEND);
glDepthFunc(GL_LESS);
render_sprites(current, batch.size, true);
}
render_sprites(current, batch);
i += batch.size - 1; ++batch_count;
break;

217
src/rendering/sprites.h
View File

@ -13,6 +13,44 @@
#include <stdbool.h>
#include <stddef.h>
/* interleaved vertex array data */
/* TODO: use int16_t for uvs */
/* TODO: int16_t could be used for positioning, but we would need to have more CPU calcs */
struct sprite_primitive_payload {
/* upper-left */
t_fvec2 v0;
t_fvec2 uv0;
t_color c0;
/* bottom-left */
t_fvec2 v1;
t_fvec2 uv1;
t_color c1;
/* bottom-right */
t_fvec2 v2;
t_fvec2 uv2;
t_color c2;
/* upper-right */
t_fvec2 v3;
t_fvec2 uv3;
t_color c3;
};
struct sprite_primitive_payload_without_color {
/* upper-left */
t_fvec2 v0;
t_fvec2 uv0;
/* bottom-left */
t_fvec2 v1;
t_fvec2 uv1;
/* bottom-right */
t_fvec2 v2;
t_fvec2 uv2;
/* upper-right */
t_fvec2 v3;
t_fvec2 uv3;
};
/*
* an implementation note:
* try to avoid doing expensive work in the push functions,
@ -65,6 +103,7 @@ static struct sprite_batch {
int atlas_id;
size_t size; /* how many primitives are in current batch */
bool blend; /* whether it's blended or not */
bool colored; /* whether color inmformation is needed to be passed */
} collect_sprite_batch(const struct primitive_2d *primitives, size_t len) {
/* assumes that first primitive is already a sprite */
struct sprite_batch result = {
@ -93,6 +132,13 @@ static struct sprite_batch {
!= result.atlas_id)
break;
/* if all are effectively without modulation we can skip sending color data */
if (!result.colored && (current->sprite.color.r != 255 ||
current->sprite.color.g != 255 ||
current->sprite.color.b != 255 ||
current->sprite.color.a != 255 ))
result.colored = true;
++result.size;
}
@ -102,17 +148,31 @@ static struct sprite_batch {
/* assumes that orthogonal matrix setup is done already */
static void render_sprites(const struct primitive_2d primitives[],
const size_t len,
const bool reversed)
const struct sprite_batch batch)
{
/* single vertex array is used for every batch with NULL glBufferData() trick at the end */
static GLuint vertex_array = 0;
if (vertex_array == 0)
glGenBuffers(1, &vertex_array);
if (batch.blend) {
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDepthFunc(GL_ALWAYS);
} else {
glDisable(GL_BLEND);
glDepthFunc(GL_LESS);
}
size_t payload_size;
if (batch.colored)
payload_size = sizeof (struct sprite_primitive_payload);
else
payload_size = sizeof (struct sprite_primitive_payload_without_color);
glBindBuffer(GL_ARRAY_BUFFER, vertex_array);
glBufferData(GL_ARRAY_BUFFER,
sizeof (struct sprite_primitive_payload) * len,
payload_size * batch.size,
NULL,
GL_STREAM_DRAW);
@ -122,11 +182,10 @@ static void render_sprites(const struct primitive_2d primitives[],
/* vertex population over a mapped buffer */
{
/* TODO: check errors, ensure alignment ? */
struct sprite_primitive_payload *const payload =
glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
void *const payload = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
for (size_t i = 0; i < len; ++i) {
const size_t cur = reversed ? len - i - 1: i;
for (size_t i = 0; i < batch.size; ++i) {
const size_t cur = !batch.blend ? batch.size - i - 1: i; /* render opaques front to back */
const struct sprite_primitive sprite = primitives[cur].sprite;
const t_rect srcrect =
@ -137,49 +196,25 @@ static void render_sprites(const struct primitive_2d primitives[],
const float xr = (float)srcrect.x / (float)dims.w;
const float yr = (float)srcrect.y / (float)dims.h;
/* non-rotated case */
t_fvec2 uv0 = { xr + wr * sprite.flip_x, yr + hr * sprite.flip_y };
t_fvec2 uv1 = { xr + wr * sprite.flip_x, yr + hr * !sprite.flip_y };
t_fvec2 uv2 = { xr + wr * !sprite.flip_x, yr + hr * !sprite.flip_y };
t_fvec2 uv3 = { xr + wr * !sprite.flip_x, yr + hr * sprite.flip_y };
t_fvec2 v0, v1, v2, v3;
/* todo: fast PI/2 degree divisible rotations? */
if (sprite.rotation == 0.0f) {
payload[i] = (struct sprite_primitive_payload) {
/* upper-left */
.v0 = {
sprite.rect.x,
sprite.rect.y },
.uv0 = {
xr + wr * sprite.flip_x,
yr + hr * sprite.flip_y, },
/* non-rotated case */
/* bottom-left */
.v1 = {
(sprite.rect.x),
(sprite.rect.y + sprite.rect.h) },
.uv1 = {
xr + wr * sprite.flip_x,
yr + hr * !sprite.flip_y, },
v0 = (t_fvec2){ sprite.rect.x, sprite.rect.y };
v1 = (t_fvec2){ sprite.rect.x, sprite.rect.y + sprite.rect.h };
v2 = (t_fvec2){ sprite.rect.x + sprite.rect.w, sprite.rect.y + sprite.rect.h };
v3 = (t_fvec2){ sprite.rect.x + sprite.rect.w, sprite.rect.y };
/* bottom-right */
.v2 = {
(sprite.rect.x + sprite.rect.w),
(sprite.rect.y + sprite.rect.h) },
.uv2 = {
xr + wr * !sprite.flip_x,
yr + hr * !sprite.flip_y, },
} else if (sprite.rect.w == sprite.rect.h) {
/* rotated square case */
/* upper-right */
.v3 = {
(sprite.rect.x + sprite.rect.w),
(sprite.rect.y) },
.uv3 = {
xr + wr * !sprite.flip_x,
yr + hr * sprite.flip_y, },
/* equal for all (flat shaded) */
.c0 = sprite.color,
.c1 = sprite.color,
.c2 = sprite.color,
.c3 = sprite.color,
};
} else {
/* rotated case */
const t_fvec2 c = frect_center(sprite.rect);
const t_fvec2 t = fast_cossine(sprite.rotation + (float)M_PI_4);
const t_fvec2 d = {
@ -187,38 +222,28 @@ static void render_sprites(const struct primitive_2d primitives[],
.y = t.y * sprite.rect.h * (float)M_SQRT1_2,
};
payload[i] = (struct sprite_primitive_payload) {
/* upper-left */
.v0 = {
c.x - d.x,
c.y - d.y },
.uv0 = {
xr + wr * sprite.flip_x,
yr + hr * sprite.flip_y, },
v0 = (t_fvec2){ c.x - d.x, c.y - d.y };
v1 = (t_fvec2){ c.x - d.y, c.y + d.x };
v2 = (t_fvec2){ c.x + d.x, c.y + d.y };
v3 = (t_fvec2){ c.x + d.y, c.y - d.x };
/* bottom-left */
.v1 = {
c.x - d.y,
c.y + d.x },
.uv1 = {
xr + wr * sprite.flip_x,
yr + hr * !sprite.flip_y, },
} else {
/* rotated non-square case*/
/* bottom-right */
.v2 = {
c.x + d.x,
c.y + d.y },
.uv2 = {
xr + wr * !sprite.flip_x,
yr + hr * !sprite.flip_y, },
CRY("Rotation", "Unimplemented");
}
/* upper-right */
.v3 = {
c.x + d.y,
c.y - d.x },
.uv3 = {
xr + wr * !sprite.flip_x,
yr + hr * sprite.flip_y, },
if (batch.colored)
((struct sprite_primitive_payload *)payload)[i] = (struct sprite_primitive_payload) {
.v0 = v0,
.v1 = v1,
.v2 = v2,
.v3 = v3,
.uv0 = uv0,
.uv1 = uv1,
.uv2 = uv2,
.uv3 = uv3,
/* equal for all (flat shaded) */
.c0 = sprite.color,
@ -226,37 +251,65 @@ static void render_sprites(const struct primitive_2d primitives[],
.c2 = sprite.color,
.c3 = sprite.color,
};
}
else
((struct sprite_primitive_payload_without_color *)payload)[i] = (struct sprite_primitive_payload_without_color) {
.v0 = v0,
.v1 = v1,
.v2 = v2,
.v3 = v3,
.uv0 = uv0,
.uv1 = uv1,
.uv2 = uv2,
.uv3 = uv3,
};
}
glUnmapBuffer(GL_ARRAY_BUFFER);
}
GLsizei off;
GLsizei voff;
GLsizei uvoff;
if (batch.colored) {
off = offsetof(struct sprite_primitive_payload, v1);
voff = offsetof(struct sprite_primitive_payload, v0);
uvoff = offsetof(struct sprite_primitive_payload, uv0);
} else {
off = offsetof(struct sprite_primitive_payload_without_color, v1);
voff = offsetof(struct sprite_primitive_payload_without_color, v0);
uvoff = offsetof(struct sprite_primitive_payload_without_color, uv0);
}
/* vertex specification */
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(2,
GL_FLOAT,
offsetof(struct sprite_primitive_payload, v1),
(void *)offsetof(struct sprite_primitive_payload, v0));
off,
(void *)(size_t)voff);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glClientActiveTexture(GL_TEXTURE0);
glTexCoordPointer(2,
GL_FLOAT,
offsetof(struct sprite_primitive_payload, v1),
(void *)offsetof(struct sprite_primitive_payload, uv0));
off,
(void *)(size_t)uvoff);
if (batch.colored) {
glEnableClientState(GL_COLOR_ARRAY);
glColorPointer(4,
GL_UNSIGNED_BYTE,
offsetof(struct sprite_primitive_payload, v1),
off,
(void *)offsetof(struct sprite_primitive_payload, c0));
} else
glColor4ub(255, 255, 255, 255);
textures_bind(&ctx.texture_cache, primitives->sprite.texture_key, GL_TEXTURE_2D);
bind_quad_element_buffer();
glDrawElements(GL_TRIANGLES, 6 * (GLsizei)len, GL_UNSIGNED_SHORT, NULL);
glDrawElements(GL_TRIANGLES, 6 * (GLsizei)batch.size, GL_UNSIGNED_SHORT, NULL);
/* clear the state */
glBufferData(GL_ARRAY_BUFFER, 0, NULL, GL_STREAM_DRAW);