From e47b761a2ca79b7176d87a0e41f239f9f245714e Mon Sep 17 00:00:00 2001
From: veclavtalica <veclavtalica@tutamail.com>
Date: Fri, 28 Feb 2025 23:50:12 +0300
Subject: [PATCH] twn_lines.c: introduction with proper impl
---
CMakeLists.txt | 1 +
apps/examples/circle-raster/game.c | 4 +-
src/rendering/twn_deferred_commands.h | 6 ++
src/rendering/twn_draw.c | 35 ++---------
src/rendering/twn_draw_c.h | 11 ++--
src/rendering/twn_gl_15_rendering.c | 29 ++++-----
src/rendering/twn_lines.c | 87 +++++++++++++++++++++++++++
src/twn_amalgam.c | 1 +
8 files changed, 124 insertions(+), 50 deletions(-)
create mode 100644 src/rendering/twn_lines.c
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d3702b8..ecceff2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -106,6 +106,7 @@ set(TWN_NONOPT_SOURCE_FILES
src/rendering/twn_circles.c
src/rendering/twn_skybox.c
src/rendering/twn_models.c
+ src/rendering/twn_lines.c
)
set(TWN_SOURCE_FILES
diff --git a/apps/examples/circle-raster/game.c b/apps/examples/circle-raster/game.c
index f33868a..6e75e91 100644
--- a/apps/examples/circle-raster/game.c
+++ b/apps/examples/circle-raster/game.c
@@ -121,6 +121,8 @@ void game_tick(void) {
if (input_action_pressed("down") && state->r > 2)
state->r -= 1;
+ draw_circle(mouse_snap, state->r * 8, (Color){125, 125, 125, 125});
+
int32_t const rsi = (int32_t)state->r * (int32_t)state->r;
int32_t acc = 1;
for (int32_t iy = (int32_t)state->r - 1; iy >= 0; --iy) {
@@ -133,8 +135,6 @@ void game_tick(void) {
}
}
- draw_circle(mouse_snap, state->r * 8, (Color){125, 125, 125, 125});
-
/* uncomment to see performance difference between variants */
// benchmark(state);
}
diff --git a/src/rendering/twn_deferred_commands.h b/src/rendering/twn_deferred_commands.h
index 5e8429e..897980e 100644
--- a/src/rendering/twn_deferred_commands.h
+++ b/src/rendering/twn_deferred_commands.h
@@ -4,6 +4,7 @@
#include "twn_types.h"
#include "twn_gpu_texture_c.h"
#include "twn_textures_c.h"
+#include "twn_types_c.h"
#include <stddef.h>
#include <stdbool.h>
@@ -49,6 +50,11 @@ typedef struct {
uint32_t element_count;
uint32_t range_start, range_end;
+ enum {
+ DEFERRED_COMMAND_DRAW_GEOMETRY_MODE_TRIANGLES = 0,
+ DEFERRED_COMMAND_DRAW_GEOMETRY_MODE_LINES = 1,
+ } geometry_mode;
+
bool constant_colored;
bool textured, texture_repeat, uses_gpu_key;
} DeferredCommandDraw;
diff --git a/src/rendering/twn_draw.c b/src/rendering/twn_draw.c
index c13d738..cf7af86 100644
--- a/src/rendering/twn_draw.c
+++ b/src/rendering/twn_draw.c
@@ -278,7 +278,7 @@ static void render_2d(void) {
}
/* TODO: batching */
- case PRIMITIVE_2D_LINE: {
+ case PRIMITIVE_2D_LINES: {
struct Render2DInvocation const invocation = {
.primitive = current,
.layer = layer,
@@ -327,8 +327,8 @@ static void render_2d(void) {
case PRIMITIVE_2D_CIRCLE:
render_circle(&invocation.primitive->circle);
break;
- case PRIMITIVE_2D_LINE:
- render_line(&invocation.primitive->line);
+ case PRIMITIVE_2D_LINES:
+ render_lines(&invocation.primitive->line);
break;
case PRIMITIVE_2D_TEXT:
default:
@@ -359,8 +359,8 @@ static void render_2d(void) {
case PRIMITIVE_2D_TEXT:
render_text(&invocation.primitive->text);
break;
- case PRIMITIVE_2D_LINE:
- render_line(&invocation.primitive->line);
+ case PRIMITIVE_2D_LINES:
+ render_lines(&invocation.primitive->line);
break;
default:
SDL_assert(false);
@@ -538,31 +538,6 @@ void issue_deferred_draw_commands(void) {
}
-/* TODO: Support thickness */
-void draw_line(Vec2 start,
- Vec2 finish,
- float thickness,
- Color color)
-{
- if (fabsf(1.0f - thickness) >= 0.00001f)
- log_warn("Thickness isn't yet implemented for line drawing (got %f)", (double)thickness);
-
- LinePrimitive line = {
- .start = start,
- .finish = finish,
- .thickness = thickness,
- .color = color,
- };
-
- Primitive2D primitive = {
- .type = PRIMITIVE_2D_LINE,
- .line = line,
- };
-
- arrput(ctx.render_queue_2d, primitive);
-}
-
-
void draw_box(Rect rect,
float thickness,
Color color)
diff --git a/src/rendering/twn_draw_c.h b/src/rendering/twn_draw_c.h
index 15c4220..9ffc99f 100644
--- a/src/rendering/twn_draw_c.h
+++ b/src/rendering/twn_draw_c.h
@@ -69,9 +69,12 @@ typedef struct SpritePrimitive {
bool repeat;
} SpritePrimitive;
+/* batched in place */
typedef struct LinePrimitive {
- Vec2 start;
- Vec2 finish;
+ struct LineVertex {
+ Vec3 position;
+ Color color;
+ } *vertices;
float thickness;
Color color;
} LinePrimitive;
@@ -97,7 +100,7 @@ typedef struct TextPrimitive {
typedef enum Primitive2DType {
PRIMITIVE_2D_SPRITE,
- PRIMITIVE_2D_LINE,
+ PRIMITIVE_2D_LINES,
PRIMITIVE_2D_RECT,
PRIMITIVE_2D_CIRCLE,
PRIMITIVE_2D_TEXT,
@@ -319,7 +322,7 @@ IndexBuffer get_circle_element_buffer(void);
void render_circle(const CirclePrimitive *circle);
-void render_line(const LinePrimitive *line);
+void render_lines(LinePrimitive *line);
void render_rectangle(const RectPrimitive *rectangle);
diff --git a/src/rendering/twn_gl_15_rendering.c b/src/rendering/twn_gl_15_rendering.c
index 0b38856..6fe7dec 100644
--- a/src/rendering/twn_gl_15_rendering.c
+++ b/src/rendering/twn_gl_15_rendering.c
@@ -630,12 +630,24 @@ void finally_draw_command(DeferredCommandDraw command) {
textures_bind(&ctx.texture_cache, command.texture_key);
}
+ GLenum geometry_mode;
+ switch (command.geometry_mode) {
+ case DEFERRED_COMMAND_DRAW_GEOMETRY_MODE_TRIANGLES:
+ geometry_mode = GL_TRIANGLES;
+ break;
+ case DEFERRED_COMMAND_DRAW_GEOMETRY_MODE_LINES:
+ geometry_mode = GL_LINES;
+ break;
+ default:
+ SDL_assert(false);
+ }
+
if (command.element_buffer) {
SDL_assert(command.element_count != 0);
if (command.range_start == command.range_end)
- glDrawElements(GL_TRIANGLES, command.element_count, GL_UNSIGNED_SHORT, NULL);
+ glDrawElements(geometry_mode, command.element_count, GL_UNSIGNED_SHORT, NULL);
else
- glDrawRangeElements(GL_TRIANGLES,
+ glDrawRangeElements(geometry_mode,
command.range_start,
command.range_end,
command.element_count,
@@ -643,7 +655,7 @@ void finally_draw_command(DeferredCommandDraw command) {
NULL);
} else {
SDL_assert(command.primitive_count != 0);
- glDrawArrays(GL_TRIANGLES, 0, command.primitive_count);
+ glDrawArrays(geometry_mode, 0, command.primitive_count);
}
/* state clearing */
@@ -662,14 +674,3 @@ void finally_draw_command(DeferredCommandDraw command) {
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
-
-
-void render_line(const LinePrimitive *line) {
- finally_use_2d_pipeline();
- glBegin(GL_LINES);
- glColor4ub(line->color.r, line->color.g, line->color.b, line->color.a);
- glVertex2f(line->start.x, line->start.y);
- glColor4ub(line->color.r, line->color.g, line->color.b, line->color.a);
- glVertex2f(line->finish.x, line->finish.y);
- glEnd();
-}
diff --git a/src/rendering/twn_lines.c b/src/rendering/twn_lines.c
new file mode 100644
index 0000000..c5e282b
--- /dev/null
+++ b/src/rendering/twn_lines.c
@@ -0,0 +1,87 @@
+#include "twn_draw_c.h"
+#include "twn_draw.h"
+#include "twn_engine_context_c.h"
+#include "twn_util.h"
+
+#include <stb_ds.h>
+
+/* TODO: Support thickness */
+void draw_line(Vec2 start,
+ Vec2 finish,
+ float thickness,
+ Color color)
+{
+ if (fabsf(1.0f - thickness) >= 0.00001f)
+ log_warn("Thickness isn't yet implemented for line drawing (got %f)", (double)thickness);
+
+ struct LineVertex const v0 = { .position = (Vec3){start.x, start.y, 0}, .color = color };
+ struct LineVertex const v1 = { .position = (Vec3){finish.x, finish.y, 0}, .color = color };
+
+ /* combine with existing position if it's compatible */
+ if (arrlenu(ctx.render_queue_2d) != 0) {
+ Primitive2D *const primitive = &ctx.render_queue_2d[arrlenu(ctx.render_queue_2d) - 1];
+ if (primitive->type == PRIMITIVE_2D_LINES && fabsf(primitive->line.thickness - thickness) < 0.00001f &&
+ primitive->line.color.a == color.a && primitive->line.color.b == color.b &&
+ primitive->line.color.r == color.r && primitive->line.color.g == color.g) {
+
+ arrput(primitive->line.vertices, v0);
+ arrput(primitive->line.vertices, v1);
+ return;
+ }
+ }
+
+ LinePrimitive line = {
+ .thickness = thickness,
+ .color = color,
+ };
+
+ Primitive2D primitive = {
+ .type = PRIMITIVE_2D_LINES,
+ .line = line,
+ };
+
+ arrput(primitive.line.vertices, v0);
+ arrput(primitive.line.vertices, v1);
+ arrput(ctx.render_queue_2d, primitive);
+}
+
+
+void render_lines(LinePrimitive *line) {
+ DeferredCommandDraw command = {0};
+
+ VertexBuffer buffer = get_scratch_vertex_array();
+ specify_vertex_buffer(buffer, line->vertices, arrlenu(line->vertices) * sizeof (*line->vertices));
+
+ command.vertices = (AttributeArrayPointer) {
+ .arity = 3,
+ .type = TWN_FLOAT,
+ .stride = sizeof (struct LineVertex),
+ .offset = offsetof (struct LineVertex, position),
+ .buffer = buffer
+ };
+
+ command.colors = (AttributeArrayPointer) {
+ .arity = 4,
+ .type = TWN_UNSIGNED_BYTE,
+ .stride = sizeof (struct LineVertex),
+ .offset = offsetof (struct LineVertex, color),
+ .buffer = buffer
+ };
+
+ command.primitive_count = arrlenu(line->vertices);
+
+ command.geometry_mode = DEFERRED_COMMAND_DRAW_GEOMETRY_MODE_LINES;
+ command.pipeline = PIPELINE_2D;
+
+ command.depth_range_high = depth_range_high;
+ command.depth_range_low = depth_range_low;
+
+ DeferredCommand final_command = {
+ .type = DEFERRED_COMMAND_TYPE_DRAW,
+ .draw = command
+ };
+
+ /* TODO: should it be deleted here? */
+ arrfree(line->vertices);
+ arrpush(deferred_commands, final_command);
+}
diff --git a/src/twn_amalgam.c b/src/twn_amalgam.c
index 6cfa3a5..dee1e81 100644
--- a/src/twn_amalgam.c
+++ b/src/twn_amalgam.c
@@ -23,3 +23,4 @@
#include "rendering/twn_triangles.c"
#include "rendering/twn_billboards.c"
#include "rendering/twn_models.c"
+#include "rendering/twn_lines.c"