a-game

commit 0eaf9d5d0307ca495e597d1896aa308c269d93aa
parent 647442853925b6467934e90f42ca9fc8f2980e3e
Author: Amin Mesbah <dev@aminmesbah.com>
Date:   Thu, 31 May 2018 23:44:16 -0700

Scale, rotate, and tranlate a triangle

Diffstat:
M
shader/triangle_f.glsl
 | 
4
++--
M
shader/triangle_v.glsl
 | 
4
+++-
M
src/game.c
 | 
14
+++++++++++---
M
src/game.h
 | 
6
+++---
M
src/platform_linux.c
 | 
6
+++---

5 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/shader/triangle_f.glsl b/shader/triangle_f.glsl
@@ -2,9 +2,9 @@
 
 in vec4 vertex_color;
 
-out vec4 color;
+out vec4 frag_color;
 
 void main()
 {
-    color = vertex_color;
+    frag_color = vertex_color;
 }
diff --git a/shader/triangle_v.glsl b/shader/triangle_v.glsl
@@ -5,8 +5,10 @@ layout (location = 1) in vec3 color;
 
 out vec4 vertex_color;
 
+uniform mat4 transform;
+
 void main()
 {
-    gl_Position = vec4(position, 0.0f, 1.0f);
+    gl_Position = transform * vec4(position, 0.0f, 1.0f);
     vertex_color = vec4(color, 1.0f);
 }
diff --git a/src/game.c b/src/game.c
@@ -1,5 +1,7 @@
 #include "game.h"
 
+#include <math.h>
+
 
 void game_init(struct GameState *game_state)
 {
@@ -33,20 +35,26 @@ void game_init(struct GameState *game_state)
 }
 
 
-void game_update_and_render(struct GameState *game_state)
+void game_update_and_render(struct GameState *game_state, float dt)
 {
     glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
     glClear(GL_COLOR_BUFFER_BIT);
 
-    glUseProgram(game_state->triangle_shader.program);
+    m4 trans = glmth_m4_init_id();
+    trans = glmth_translate(trans, glmth_v3_init(0.5f * cosf(dt), 0.5f * 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);
 
+    shader_use(&game_state->triangle_shader);
+    shader_setm4(&game_state->triangle_shader, "transform", &trans);
     glBindVertexArray(game_state->vao_id);
     glDrawArrays(GL_TRIANGLES, 0, 3);
     glBindVertexArray(0);
 }
 
 
-void game_deinit(struct GameState *game_state)
+void game_cleanup(struct GameState *game_state)
 {
     glDeleteVertexArrays(1, &game_state->vao_id);
     glDeleteBuffers(1, &game_state->vbo_id);
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);
+typedef void (game_update_and_render_func)(struct GameState *game_state, float dt);
 
 void game_init(struct GameState *game_state);
-void game_update_and_render(struct GameState *game_state);
-void game_deinit(struct GameState *game_state);
+void game_update_and_render(struct GameState *game_state, float dt);
+void game_cleanup(struct GameState *game_state);
 
 #endif
diff --git a/src/platform_linux.c b/src/platform_linux.c
@@ -85,16 +85,16 @@ int main(void)
                 // TODO: fall back to backup?
             }
         }
-        game_code.game_update_and_render(&game_state);
+        game_code.game_update_and_render(&game_state, lag/PLATFORM_SECOND);
 #else
-        game_update_and_render(&game_state);
+        game_update_and_render(&game_state, lag/PLATFORM_SECOND);
 #endif // PLATFORM_HOTLOAD_GAME_CODE
 
         glfwSwapBuffers(window);
         glfwPollEvents();
     }
 
-    game_deinit(&game_state);
+    game_cleanup(&game_state);
 
     glfwDestroyWindow(window);
     glfwTerminate();