a-game

commit c833ecd4cdee55419de0b4c42cfee2d0fddffcee
parent cc6a022c5d380463917e0f8ec3c5abce347dc14a
Author: amin <dev@aminmesbah.com>
Date:   Sat,  2 Jun 2018 03:50:06 +0000

Set up projection and view matrices

And make an actual equilateral triangle. That was really annoying me.

FossilOrigin-Name: 0bf4c1f2ec9041f20b1d190e3cc934ac730b48697e072c6298ca14ee211aaf84
Diffstat:
M
shader/triangle_v.glsl
 | 
6
++++--
M
src/game.c
 | 
38
+++++++++++++++++++++++++++-----------
M
src/game.h
 | 
6
+++---
M
src/platform_linux.c
 | 
6
+++---
M
src/platform_linux.h
 | 
2
+-

5 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/shader/triangle_v.glsl b/shader/triangle_v.glsl
@@ -5,10 +5,12 @@ layout (location = 1) in vec3 color;
 
 out vec4 vertex_color;
 
-uniform mat4 transform;
+uniform mat4 model;
+uniform mat4 projection;
+uniform mat4 view;
 
 void main()
 {
-    gl_Position = transform * vec4(position, 0.0f, 1.0f);
+    gl_Position = projection * view * model * vec4(position, 0.0f, 1.0f);
     vertex_color = vec4(color, 1.0f);
 }
diff --git a/src/game.c b/src/game.c
@@ -3,13 +3,19 @@
 #include <math.h>
 
 
-void game_init(struct GameState *game_state)
+void game_init(struct GameState *game_state, uint32_t screen_width, uint32_t screen_height)
 {
+    glViewport(0, 0, screen_width, screen_height);
+
+    float circumradius = 0.5f;
+    float inradius = circumradius * sinf(glmth_rad(30.0f));
+    float half_side_length = circumradius * cosf(glmth_rad(30.0f));
+
     GLfloat triangle_vertices[] = {
-        // positions   // colors
-        -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,
-         0.5f, -0.5f,  0.0f,  1.0f,  0.0f,
-         0.0f,  0.5f,  0.0f,  0.0f,  1.0f,
+        // 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;
@@ -35,19 +41,29 @@ void game_init(struct GameState *game_state)
 }
 
 
-void game_update_and_render(struct GameState *game_state, float dt)
+void game_update_and_render(struct GameState *game_state, float dt, uint32_t screen_width, uint32_t screen_height)
 {
     glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
     glClear(GL_COLOR_BUFFER_BIT);
 
-    m4 trans = glmth_m4_init_id();
-    trans = glmth_translate(trans, glmth_v3_init(0.5f * cosf(dt), 0.5f * sinf(dt), 0.0f));
+    m4 model = glmth_m4_init_id();
+    model = glmth_translate(model, glmth_v3_init(1.5f * cosf(dt), 1.5f * sinf(dt), 0.0f));
     float scale_factor = fabs(1.0f * sinf(dt));
-    trans = glmth_scale(trans, glmth_v3_init(scale_factor, scale_factor, scale_factor));
-    trans = glmth_rotate_z(trans, -dt);
+    model = glmth_scale(model, glmth_v3_init(scale_factor, scale_factor, scale_factor));
+    model = glmth_rotate_z(model, -dt);
 
     shader_use(&game_state->triangle_shader);
-    shader_setm4(&game_state->triangle_shader, "transform", &trans);
+    shader_setm4(&game_state->triangle_shader, "model", &model);
+
+    m4 projection = glmth_m4_init_id();
+    projection = glmth_projection_perspective_fov(glmth_rad(45.0f), (float)screen_width / (float)screen_height, 0.1f, 100.0f);
+    shader_setm4(&game_state->triangle_shader, "projection", &projection);
+
+    m4 view = glmth_m4_init_id();
+    v3 camera_pos = glmth_v3_init(0.0f, 0.0f, 6.0f);
+    view = glmth_camera_look_at(camera_pos, glmth_v3_a(camera_pos, glmth_v3_init(0.0f, 0.0f, -1.0f)), glmth_v3_init(0.0f, 1.0f, 0.0f));
+    shader_setm4(&game_state->triangle_shader, "view", &view);
+
     glBindVertexArray(game_state->vao_id);
     glDrawArrays(GL_TRIANGLES, 0, 3);
     glBindVertexArray(0);
diff --git a/src/game.h b/src/game.h
@@ -11,10 +11,10 @@ struct GameState
     struct Shader triangle_shader;
 };
 
-typedef void (game_update_and_render_func)(struct GameState *game_state, float dt);
+typedef void (game_update_and_render_func)(struct GameState *game_state, float dt, uint32_t screen_width, uint32_t screen_height);
 
-void game_init(struct GameState *game_state);
-void game_update_and_render(struct GameState *game_state, float dt);
+void game_init(struct GameState *game_state, uint32_t screen_width, uint32_t screen_height);
+void game_update_and_render(struct GameState *game_state, float dt, uint32_t screen_width, uint32_t screen_height);
 void game_cleanup(struct GameState *game_state);
 
 #endif
diff --git a/src/platform_linux.c b/src/platform_linux.c
@@ -56,7 +56,7 @@ int main(void)
     }
 
     struct GameState game_state = {0};
-    game_init(&game_state);
+    game_init(&game_state, PLATFORM_SCR_WIDTH, PLATFORM_SCR_HEIGHT);
 
 #ifdef PLATFORM_HOTLOAD_GAME_CODE
     struct GameCode game_code = load_game_code(PLATFORM_GAME_LIB_PATH);
@@ -85,9 +85,9 @@ int main(void)
                 // TODO: fall back to backup?
             }
         }
-        game_code.game_update_and_render(&game_state, lag/PLATFORM_SECOND);
+        game_code.game_update_and_render(&game_state, lag/PLATFORM_SECOND, PLATFORM_SCR_WIDTH, PLATFORM_SCR_HEIGHT);
 #else
-        game_update_and_render(&game_state, lag/PLATFORM_SECOND);
+        game_update_and_render(&game_state, lag/PLATFORM_SECOND, PLATFORM_SCR_WIDTH, PLATFORM_SCR_HEIGHT);
 #endif // PLATFORM_HOTLOAD_GAME_CODE
 
         glfwSwapBuffers(window);
diff --git a/src/platform_linux.h b/src/platform_linux.h
@@ -7,7 +7,7 @@
 #include "game.h"
 
 #define PLATFORM_GAME_LIB_PATH "./build/release/game.so"
-#define PLATFORM_SCR_WIDTH 800
+#define PLATFORM_SCR_WIDTH 600
 #define PLATFORM_SCR_HEIGHT 600
 
 #define PLATFORM_SECOND 1000.0f