Initial public api version

examples/basic.cpp

@@ -1,6 +1,31 @@
 #include <glerminal.h>
 
+namespace
+{
+	void init()
+	{
+		glerminal_update_palette(0, 0xFF0000FF);
+		glerminal_update_palette(1, 0x00FF00FF);
+
+		glerminal_update_sprite(0, {
+			1, 1, 1, 1, 1, 1, 1, 1,
+			1, 0, 0, 0, 0, 0, 0, 0,
+			1, 0, 0, 0, 0, 0, 0, 0,
+			1, 0, 0, 0, 0, 0, 0, 0,
+			1, 0, 0, 0, 0, 0, 0, 0,
+			1, 0, 0, 0, 0, 0, 0, 0,
+			1, 0, 0, 0, 0, 0, 0, 0,
+			1, 0, 0, 0, 0, 0, 0, 0
+		});
+	}
+
+	void mainloop(float dt)
+	{
+		glerminal_flush();
+	}
+}
+
 int main(int argc, char** argv)
 {
-	glerminal_run(glerminal_flush);
+	glerminal_run(init, mainloop);
 }

include/glerminal.h

@@ -12,7 +12,8 @@ enum
 	GLERMINAL_CELL_AREA = GLERMINAL_CELL_SIZE * GLERMINAL_CELL_SIZE
 };
 
-typedef void (*glerminal_main_cb)();
+typedef void (*glerminal_init_cb)();
+typedef void (*glerminal_main_cb)(float dt);
 
 typedef struct glerminal_sprite
 {
@@ -20,10 +21,10 @@ typedef struct glerminal_sprite
 } glerminal_sprite;
 
 /**
- * @brief Run the application's mainloop
+ * @brief Call init once, then run the application's mainloop
  * @param main main calllback
  */
-void glerminal_run(glerminal_main_cb main);
+void glerminal_run(glerminal_init_cb init, glerminal_main_cb main);
 
 /**
  * @brief Update the displayed screen contents to the current state of the library
@@ -47,6 +48,20 @@ void glerminal_set(unsigned char x, unsigned char y, unsigned char layer, unsign
  */
 unsigned char glerminal_get(unsigned char x, unsigned char y, unsigned char layer);
 
+/**
+ * @brief Upload sprite to the given sprite ID
+ * @param id The ID of the sprite to change
+ * @param sprite The new sprite
+ */
+void glerminal_update_sprite(unsigned char id, glerminal_sprite sprite);
+
+/**
+ * @brief Update palette color at index ID
+ * @param id Palette index to update
+ * @param color New color
+ */
+void glerminal_update_palette(unsigned char id, unsigned int color);
+
 #ifdef __cplusplus
 }
 #endif

source/glerminal-private.h

@@ -25,7 +25,7 @@ namespace glerminal
 	class glerminal
 	{
 	public:
-		glerminal(glerminal_main_cb main);
+		glerminal(glerminal_init_cb init, glerminal_main_cb main);
 		~glerminal();
 
 		glerminal(const glerminal&) = delete;
@@ -41,6 +41,9 @@ namespace glerminal
 		void set(unsigned char x, unsigned char y, unsigned char layer, unsigned char sprite);
 		unsigned char get(unsigned char x, unsigned char y, unsigned char layer) const;
 
+		void update_sprite(unsigned char id, glerminal_sprite sprite);
+		void update_palette_color(unsigned char id, unsigned int color);
+
 	private:
 		GLFWwindow* m_window;
 

source/glerminal.cpp

@@ -89,7 +89,7 @@ namespace
 		"void main()\n"
 		"{\n"
 		"	gl_Position = vec4(position * 2 + 1, 0, 1);\n"
-		"	texcoord = -position;\n"
+		"	texcoord = vec2(position.x + 1, -position.y);\n"
 		"}";
 
 	constexpr char* SCREEN_FRAGMENT_SHADER_SOURCE =
@@ -111,7 +111,7 @@ namespace
 
 namespace glerminal
 {
-	glerminal::glerminal(glerminal_main_cb main) :
+	glerminal::glerminal(glerminal_init_cb init, glerminal_main_cb main) :
 		m_main(main),
 		m_cells{ },
 		m_sprites{ },
@@ -126,6 +126,11 @@ namespace glerminal
 		}
 
 		// unsure if this should be an error
+		if (!init)
+		{
+			throw std::runtime_error("No init callback provided.");
+		}
+
 		if (!m_main)
 		{
 			throw std::runtime_error("No main callback provided.");
@@ -135,6 +140,8 @@ namespace glerminal
 		init_gl();
 
 		GLERMINAL_G = this;
+
+		init();
 	}
 
 	glerminal::~glerminal()
@@ -147,17 +154,25 @@ namespace glerminal
 
 	void glerminal::run()
 	{
+		float last = glfwGetTime();
 		while (!glfwWindowShouldClose(m_window))
 		{
 			glfwPollEvents();
 
-			m_main();
+			const float current = glfwGetTime();
+
+			m_main(current - last);
+
+			last = current;
 		}
 	}
 
 	void glerminal::flush()
 	{
+		// use dirty flag later
 		glNamedBufferData(m_instance_vbo, sizeof(m_cells), m_cells, GL_STREAM_DRAW);
+		update_sprites();
+		update_palette();
 
 		glUseProgram(m_program);
 		glBindTexture(GL_TEXTURE_2D_ARRAY, m_sprites_texture);
@@ -196,6 +211,23 @@ namespace glerminal
 		}
 	}
 
+	void glerminal::update_sprite(unsigned char id, glerminal_sprite sprite)
+	{
+		// does this work?
+		reinterpret_cast<glerminal_sprite*>(m_sprites)[id] = sprite;
+	}
+
+	void glerminal::update_palette_color(unsigned char id, unsigned int color)
+	{
+		if (id < 16)
+		{
+			m_palette[4 * id + 0] = ((color >> 24) & 0xFF) / 255.0f;
+			m_palette[4 * id + 1] = ((color >> 16) & 0xFF) / 255.0f;
+			m_palette[4 * id + 2] = ((color >> 8) & 0xFF) / 255.0f;
+			m_palette[4 * id + 3] = ((color >> 0) & 0xFF) / 255.0f;
+		}
+	}
+
 	void glerminal::init_glfw()
 	{
 		glfwInit();
@@ -538,11 +570,11 @@ namespace glerminal
 	}
 }
 
-void glerminal_run(glerminal_main_cb main)
+void glerminal_run(glerminal_init_cb init, glerminal_main_cb main)
 {
 	try
 	{
-		glerminal::glerminal(main).run();
+		glerminal::glerminal(init, main).run();
 	}
 	catch (const std::runtime_error& e)
 	{
@@ -568,4 +600,18 @@ unsigned char glerminal_get(unsigned char x, unsigned char y, unsigned char laye
 	if (!GLERMINAL_G) { return 0; }
 
 	return GLERMINAL_G->get(x, y, layer);
+}
+
+void glerminal_update_sprite(unsigned char id, glerminal_sprite sprite)
+{
+	if (!GLERMINAL_G) { return; }
+
+	GLERMINAL_G->update_sprite(id, sprite);
+}
+
+void glerminal_update_palette(unsigned char id, unsigned int color)
+{
+	if (!GLERMINAL_G) { return; }
+
+	GLERMINAL_G->update_palette_color(id, color);
 }