commit 9b48857eac063a406f73886d2fc5a6a1fb41213b
parent b6e05f959cb88b8794b8d8db35ee5b61be741ac7
Author: amin <dev@aminmesbah.com>
Date: Fri, 8 Jun 2018 08:32:42 +0000
Render a bunch of stars drifting in the background
FossilOrigin-Name: bfe9224ce4cb52c95c8bc8799726ddbfe9f49dddd027a660a73e8115a4880891
Diffstat:
5 files changed, 205 insertions(+), 55 deletions(-)
diff --git a/shader/star_f.glsl b/shader/star_f.glsl
@@ -0,0 +1,10 @@
+#version 330 core
+
+in vec4 vertex_color;
+
+out vec4 frag_color;
+
+void main()
+{
+ frag_color = vertex_color;
+}
diff --git a/shader/star_v.glsl b/shader/star_v.glsl
@@ -0,0 +1,14 @@
+#version 330 core
+
+layout (location = 0) in vec2 position;
+
+out vec4 vertex_color;
+
+uniform mat4 model;
+uniform mat4 projection;
+
+void main()
+{
+ gl_Position = projection * model * vec4(position, 0.0f, 1.0f);
+ vertex_color = vec4(1.0f, 1.0f, 1.0f, 1.0f);
+}
diff --git a/src/game.c b/src/game.c
@@ -1,8 +1,10 @@
#include "game.h"
-#include <glad/glad.h>
+#include <assert.h>
#include <math.h>
+#include <glad/glad.h>
+
#ifdef PLATFORM_HOTLOAD_GAME_CODE
void game_load_opengl_symbols(void)
@@ -12,73 +14,177 @@ void game_load_opengl_symbols(void)
#endif
+float wrap(float n, float min, float max)
+{
+ if (n > max)
+ {
+ return min;
+ }
+ else if (n < min)
+ {
+ return max;
+ }
+ else
+ {
+ return n;
+ }
+}
+
+
+float randf(float min, float max)
+{
+ assert(min < max);
+ float random = ((float) rand()) / (float) RAND_MAX;
+ float diff = max - min;
+ float r = random * diff;
+ return min + r;
+}
+
+
void game_init(struct GameState *game_state, uint32_t screen_width, uint32_t screen_height)
{
- glViewport(0, 0, screen_width, screen_height);
-
- float circumradius = 10.0f;
- float inradius = circumradius * sinf(glmth_rad(30.0f));
- float half_side_length = circumradius * cosf(glmth_rad(30.0f));
-
- GLfloat triangle_vertices[] = {
- // positions // colors
- -half_side_length, -inradius, 1.0f, 0.0f, 0.0f,
- half_side_length, -inradius, 0.0f, 1.0f, 0.0f,
- 0.0f, circumradius, 0.0f, 0.0f, 1.0f,
- };
-
- GLuint vbo_id;
- GLuint vao_id;
- glGenVertexArrays(1, &vao_id);
- glGenBuffers(1, &vbo_id);
-
- glBindVertexArray(vao_id);
- glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
- glBufferData(GL_ARRAY_BUFFER, sizeof(triangle_vertices), triangle_vertices, GL_STATIC_DRAW);
-
- // positions
- glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(*triangle_vertices), (GLvoid*)0);
- glEnableVertexAttribArray(0);
-
- // colors
- glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(*triangle_vertices), (GLvoid*)(2 * sizeof(*triangle_vertices)));
- glEnableVertexAttribArray(1);
- glBindVertexArray(0);
-
- game_state->vao_id = vao_id;
+ // set up and load star vertex data
+ {
+ float max_speed = 0.3f;
+ game_state->stars.num_stars = NUM_STARS;
+ for (size_t i = 0; i < game_state->stars.num_stars; ++i)
+ {
+ game_state->stars.velocities[i].x = randf(-max_speed, max_speed);
+ game_state->stars.velocities[i].y = randf(-max_speed, max_speed);
+ }
+
+ for (size_t i = 0; i < game_state->stars.num_stars; ++i)
+ {
+ game_state->stars.positions[i].x = (float)(rand() % screen_width);
+ game_state->stars.positions[i].y = (float)(rand() % screen_height);
+ }
+
+ GLuint star_vao_id;
+ GLuint star_vbo_id;
+ glGenVertexArrays(1, &star_vao_id);
+ glGenBuffers(1, &star_vbo_id);
+
+ glBindVertexArray(star_vao_id);
+ glBindBuffer(GL_ARRAY_BUFFER, star_vbo_id);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(game_state->stars.positions), game_state->stars.positions, GL_DYNAMIC_DRAW);
+
+ // positions
+ glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
+ glEnableVertexAttribArray(0);
+ glBindVertexArray(0);
+
+ game_state->star_vao_id = star_vao_id;
+ game_state->star_vbo_id = star_vbo_id;
+ }
+
+ // load triangle vertex data
+ {
+ float circumradius = 10.0f;
+ float inradius = circumradius * sinf(glmth_rad(30.0f));
+ float half_side_length = circumradius * cosf(glmth_rad(30.0f));
+
+ GLfloat triangle_vertices[] = {
+ // positions // colors
+ -half_side_length, -inradius, 1.0f, 0.0f, 0.0f,
+ half_side_length, -inradius, 0.0f, 1.0f, 0.0f,
+ 0.0f, circumradius, 0.0f, 0.0f, 1.0f,
+ };
+
+ GLuint triangle_vao_id;
+ GLuint triangle_vbo_id;
+ glGenVertexArrays(1, &triangle_vao_id);
+ glGenBuffers(1, &triangle_vbo_id);
+
+ glBindVertexArray(triangle_vao_id);
+ glBindBuffer(GL_ARRAY_BUFFER, triangle_vbo_id);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(triangle_vertices), triangle_vertices, GL_STATIC_DRAW);
+
+ // positions
+ glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(*triangle_vertices), (GLvoid*)0);
+ glEnableVertexAttribArray(0);
+
+ // colors
+ glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(*triangle_vertices), (GLvoid*)(2 * sizeof(*triangle_vertices)));
+ glEnableVertexAttribArray(1);
+ glBindVertexArray(0);
+
+ game_state->triangle_vao_id = triangle_vao_id;
+ game_state->triangle_vbo_id = triangle_vbo_id;
+ }
+
+ game_state->star_shader = shader_compile("shader/star_v.glsl", "shader/star_f.glsl");
game_state->triangle_shader = shader_compile("shader/triangle_v.glsl", "shader/triangle_f.glsl");
}
void game_update_and_render(struct GameState *game_state, float dt, uint32_t screen_width, uint32_t screen_height)
{
+ // update stars
+ {
+ for (size_t i = 0; i < game_state->stars.num_stars; ++i)
+ {
+ game_state->stars.positions[i].x += game_state->stars.velocities[i].x;
+ game_state->stars.positions[i].x = wrap(game_state->stars.positions[i].x, 0, screen_width);
+
+ game_state->stars.positions[i].y += game_state->stars.velocities[i].y;
+ game_state->stars.positions[i].y = wrap(game_state->stars.positions[i].y, 0, screen_height);
+ }
+
+ glBindVertexArray(game_state->star_vao_id);
+ glBindBuffer(GL_ARRAY_BUFFER, game_state->star_vbo_id);
+ glBufferData(GL_ARRAY_BUFFER, sizeof(game_state->stars.positions), game_state->stars.positions, GL_DYNAMIC_DRAW);
+ glBindVertexArray(0);
+ }
+
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
- m4 model = glmth_m4_init_id();
- model = glmth_translate(model, glmth_v3_init(300.0f, 300.0f, 0.0f));
- model = glmth_translate(model, glmth_v3_init(100.0f * cosf(dt), 100.0f * sinf(dt), 0.0f));
- model = glmth_rotate_z(model, -dt);
- model = glmth_scale(model, glmth_v3_init(10.0f, 10.0f, 10.0f));
- float scale_factor = fabs(1.0f * sinf(dt));
- model = glmth_scale(model, glmth_v3_init(scale_factor, scale_factor, scale_factor));
-
- shader_use(&game_state->triangle_shader);
- shader_setm4(&game_state->triangle_shader, "model", &model);
-
- m4 projection = glmth_m4_init_id();
- projection = glmth_projection_ortho(0.0f, screen_width, screen_height, 0.0f, -1.0f, 1.0f);
- shader_setm4(&game_state->triangle_shader, "projection", &projection);
-
- glBindVertexArray(game_state->vao_id);
- glDrawArrays(GL_TRIANGLES, 0, 3);
- glBindVertexArray(0);
+
+ // render stars
+ {
+ m4 model = glmth_m4_init_id();
+
+ shader_use(&game_state->star_shader);
+ shader_setm4(&game_state->star_shader, "model", &model);
+
+ m4 projection = glmth_m4_init_id();
+ projection = glmth_projection_ortho(0.0f, screen_width, screen_height, 0.0f, -1.0f, 1.0f);
+ shader_setm4(&game_state->star_shader, "projection", &projection);
+
+ glBindVertexArray(game_state->star_vao_id);
+ glDrawArrays(GL_POINTS, 0, game_state->stars.num_stars - 1);
+ glBindVertexArray(0);
+ }
+
+ // render triangle
+ {
+ m4 model = glmth_m4_init_id();
+ model = glmth_translate(model, glmth_v3_init(screen_width / 2.0f, screen_height / 2.0f, 0.0f));
+ model = glmth_translate(model, glmth_v3_init(100.0f * cosf(dt), 100.0f * sinf(dt), 0.0f));
+ model = glmth_rotate_z(model, -dt);
+ model = glmth_scale(model, glmth_v3_init(10.0f, 10.0f, 10.0f));
+ float scale_factor = fabs(1.0f * sinf(dt));
+ model = glmth_scale(model, glmth_v3_init(scale_factor, scale_factor, scale_factor));
+
+ shader_use(&game_state->triangle_shader);
+ shader_setm4(&game_state->triangle_shader, "model", &model);
+
+ m4 projection = glmth_m4_init_id();
+ projection = glmth_projection_ortho(0.0f, screen_width, screen_height, 0.0f, -1.0f, 1.0f);
+ shader_setm4(&game_state->triangle_shader, "projection", &projection);
+
+ glBindVertexArray(game_state->triangle_vao_id);
+ glDrawArrays(GL_TRIANGLES, 0, 3);
+ glBindVertexArray(0);
+ }
}
void game_cleanup(struct GameState *game_state)
{
- glDeleteVertexArrays(1, &game_state->vao_id);
- glDeleteBuffers(1, &game_state->vbo_id);
+ glDeleteVertexArrays(1, &game_state->star_vao_id);
+ glDeleteVertexArrays(1, &game_state->triangle_vao_id);
+ glDeleteBuffers(1, &game_state->star_vbo_id);
+ glDeleteBuffers(1, &game_state->triangle_vbo_id);
}
diff --git a/src/game.h b/src/game.h
@@ -2,13 +2,27 @@
#define GAME_H
#include "glad/glad.h"
+#include "glmth.h"
#include "shader.h"
+#define NUM_STARS 10000
+
+struct Stars
+{
+ uint32_t num_stars;
+ v2 velocities[NUM_STARS];
+ v2 positions[NUM_STARS];
+};
+
struct GameState
{
- GLuint vao_id;
- GLuint vbo_id;
+ GLuint star_vao_id;
+ GLuint star_vbo_id;
+ GLuint triangle_vao_id;
+ GLuint triangle_vbo_id;
+ struct Shader star_shader;
struct Shader triangle_shader;
+ struct Stars stars;
};
#ifdef PLATFORM_HOTLOAD_GAME_CODE
diff --git a/src/platform_linux.c b/src/platform_linux.c
@@ -62,6 +62,12 @@ int main(void)
return -1;
}
+#ifdef USE_TEST_SEED
+ srand((uint32_t)0);
+#else
+ srand((uint32_t)time(NULL));
+#endif
+
struct GameState game_state = {0};
game_init(&game_state, PLATFORM_SCR_WIDTH, PLATFORM_SCR_HEIGHT);
