add shaders and basic drawing functions

2 files changed, 253 insertions, 2 deletions

diff --git a/src/gl/gl.c b/src/gl/gl.c
index 7b07027..7364b1c 100644
--- a/src/gl/gl.c
+++ b/src/gl/gl.c
@@ -1,4 +1,5 @@
 #include <stdlib.h>
+#include <stdbool.h>
 #include "gl/glad/glad.h"
 #include <GLFW/glfw3.h>
 #include <lua.h>
@@ -12,11 +13,34 @@
 
 
 int gl_init(lua_State *L);
+int glad_init(lua_State *L);
 int gl_terminate(lua_State *L);
+
+/* buffers */
 int gl_create_buffer(lua_State *L);
 int gl_bind_buffer(lua_State *L);
 int gl_buffer_data(lua_State *L);
 
+int gl_vertex_array_create(lua_State *L);
+int gl_vertex_array_bind(lua_State *L);
+int gl_vertex_attrib_pointer(lua_State *L);
+
+/* shaders */
+int gl_create_shader(lua_State *L);
+int gl_shader_set_source(lua_State *L);
+int gl_shader_compile(lua_State *L);
+int gl_shader_delete(lua_State *L);
+
+int gl_program_create(lua_State *L);
+int gl_program_attach_shader(lua_State *L);
+int gl_program_link(lua_State *L);
+int gl_program_use(lua_State *L);
+
+/* drawing */
+int gl_draw_arrays(lua_State *L);
+int gl_set_clear_color(lua_State *L);
+int gl_clear(lua_State *L);
+
 
 void setup_gl(lua_State *L, int honey_index)
 {
@@ -24,13 +48,66 @@ void setup_gl(lua_State *L, int honey_index)
 		hs_str_int("arrayBuffer", GL_ARRAY_BUFFER),
 	);
 
+	int buffer_usage_patterns = hs_create_table(L,
+		hs_str_int("streamDraw", GL_STREAM_DRAW),
+		hs_str_int("staticDraw", GL_STATIC_DRAW),
+		hs_str_int("dynamicDraw", GL_DYNAMIC_DRAW),
+	);
+
+	int shader_types = hs_create_table(L,
+		hs_str_int("vertexShader", GL_VERTEX_SHADER),
+		hs_str_int("fragmentShader", GL_FRAGMENT_SHADER),
+	);
+
+	int primitive_types = hs_create_table(L,
+		hs_str_int("points", GL_POINTS),
+		hs_str_int("lines", GL_LINES),
+		hs_str_int("triangles", GL_TRIANGLES),
+	);
+
+	int buffer_masks = hs_create_table(L,
+		hs_str_int("colorBuffer", GL_COLOR_BUFFER_BIT),
+		hs_str_int("depthBuffer", GL_DEPTH_BUFFER_BIT),
+		hs_str_int("stencilBuffer", GL_STENCIL_BUFFER_BIT),
+	);
+
 	hs_create_table(L,
 		hs_str_cfunc("init", gl_init),
+		hs_str_cfunc("initGlad", glad_init),
 		hs_str_cfunc("terminate", gl_terminate),
+
+		/* buffer */
 		hs_str_cfunc("createBuffer", gl_create_buffer),
 		hs_str_cfunc("bindBuffer", gl_bind_buffer),
-		hs_str_tbl("bufferTarget", buffer_binding_targets),
 		hs_str_cfunc("bufferData", gl_buffer_data),
+
+		hs_str_cfunc("createVertexArray", gl_vertex_array_create),
+		hs_str_cfunc("bindVertexArray", gl_vertex_array_bind),
+		hs_str_cfunc("vertexAttribPointer", gl_vertex_attrib_pointer),
+
+		hs_str_tbl("bufferTarget", buffer_binding_targets),
+		hs_str_tbl("bufferUsage", buffer_usage_patterns),
+
+		/* shader */
+		hs_str_cfunc("createShader", gl_create_shader),
+		hs_str_cfunc("setShaderSource", gl_shader_set_source),
+		hs_str_cfunc("compileShader", gl_shader_compile),
+		hs_str_cfunc("deleteShader", gl_shader_delete),
+
+		hs_str_cfunc("createProgram", gl_program_create),
+		hs_str_cfunc("programAttachShader", gl_program_attach_shader),
+		hs_str_cfunc("linkProgram", gl_program_link),
+		hs_str_cfunc("useProgram", gl_program_use),
+
+		hs_str_tbl("shaderType", shader_types),
+
+		/* drawing */
+		hs_str_cfunc("drawArrays", gl_draw_arrays),
+		hs_str_cfunc("setClearColor", gl_set_clear_color),
+		hs_str_cfunc("clear", gl_clear),
+
+		hs_str_tbl("primitiveType", primitive_types),
+		hs_str_tbl("bufferMask", buffer_masks),
 	);
 	lua_setfield(L, honey_index, "gl");
 }
@@ -45,6 +122,14 @@ int gl_init(lua_State *L)
 }
 
 
+int glad_init(lua_State *L)
+{
+	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
+		hs_throw_error(L, "failed to initialize GLAD");
+	}
+}
+
+
 int gl_terminate(lua_State *L)
 {
 	glfwTerminate();
@@ -95,3 +180,145 @@ int gl_buffer_data(lua_State *L)
 	free(buf);
 	return 0;
 }
+
+
+int gl_create_shader(lua_State *L)
+{
+	lua_Integer type;
+	hs_parse_args(L, hs_int(type));
+	lua_Integer shader = glCreateShader(type);
+	lua_pushinteger(L, shader);
+	return 1;
+}
+
+
+int gl_shader_set_source(lua_State *L)
+{
+	lua_Integer shader;
+	char *code;
+	hs_parse_args(L, hs_int(shader), hs_str(code));
+	glShaderSource(shader, 1, &code, NULL);
+	return 0;
+}
+
+
+int gl_shader_compile(lua_State *L)
+{
+	lua_Integer shader;
+	hs_parse_args(L, hs_int(shader));
+	glCompileShader(shader);
+	int success; char log[1024];
+	glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+	if (!success) {
+		glGetShaderInfoLog(shader, 1024, NULL, log);
+		hs_throw_error(L, "shader compilation failed: %s", log);
+	}
+	return 0;
+}
+
+
+int gl_shader_delete(lua_State *L)
+{
+	lua_Integer shader;
+	hs_parse_args(L, hs_int(shader));
+	glDeleteShader(shader);
+	return 0;
+}
+
+
+int gl_program_create(lua_State *L)
+{
+	lua_Integer program = glCreateProgram();
+	lua_pushinteger(L, program);
+	return 1;
+}
+
+
+int gl_program_attach_shader(lua_State *L)
+{
+	lua_Integer program, shader;
+	hs_parse_args(L, hs_int(program), hs_int(shader)),
+	glAttachShader(program, shader);
+	return 0;
+}
+
+
+int gl_program_link(lua_State *L)
+{
+	lua_Integer program;
+	hs_parse_args(L, hs_int(program));
+	glLinkProgram(program);
+	int success; char log[1024];
+	glGetProgramiv(program, GL_LINK_STATUS, &success);
+	if (!success) {
+		glGetProgramInfoLog(program, 1024, NULL, log);
+		hs_throw_error(L, "shader linking failed: %s", log);
+	}
+	return 0;
+}
+
+
+int gl_program_use(lua_State *L)
+{
+	lua_Integer program;
+	hs_parse_args(L, hs_int(program));
+	glUseProgram(program);
+	return 0;
+}
+
+
+int gl_vertex_array_create(lua_State *L)
+{
+	int array;
+	glGenVertexArrays(1, &array);
+	lua_pushinteger(L, array);
+	return 1;
+}
+
+
+int gl_vertex_array_bind(lua_State *L)
+{
+	lua_Integer array;
+	hs_parse_args(L, hs_int(array));
+	glBindVertexArray(array);
+	return 0;
+}
+
+
+int gl_vertex_attrib_pointer(lua_State *L)
+{
+	lua_Integer index, size, stride, offset;
+	bool normalized;
+	hs_parse_args(L, hs_int(index), hs_int(size), hs_bool(normalized), hs_int(stride), hs_int(offset));
+	glVertexAttribPointer(index, size, GL_FLOAT, 
+	                      normalized, stride*sizeof(lua_Number), 
+	                      (void*) (offset*sizeof(lua_Number)));
+	return 0;
+}
+
+
+int gl_set_clear_color(lua_State *L)
+{
+	lua_Number r, g, b, a;
+	hs_parse_args(L, hs_num(r), hs_num(g), hs_num(b), hs_num(a));
+	glClearColor(r, g, b, a);
+	return 0;
+}
+
+
+int gl_clear(lua_State *L)
+{
+	lua_Integer mask;
+	hs_parse_args(L, hs_int(mask));
+	glClear(mask);
+	return 0;
+}
+
+
+int gl_draw_arrays(lua_State *L)
+{
+	lua_Integer mode, first, count;
+	hs_parse_args(L, hs_int(mode), hs_int(first), hs_int(count));
+	glDrawArrays(mode, first, count);
+	return 0;
+}
diff --git a/src/gl/window.c b/src/gl/window.c
index 8434a5a..cb30d3f 100644
--- a/src/gl/window.c
+++ b/src/gl/window.c
@@ -6,8 +6,10 @@
 
 int window_create(lua_State *L);
 int window_destroy(lua_State *L);
+int window_make_context_current(lua_State *L);
 int window_should_close(lua_State *L);
 int window_poll_events(lua_State *L);
+int window_swap_buffers(lua_State *L);
 
 
 void setup_window(lua_State *L, int honey_index)
@@ -15,8 +17,10 @@ void setup_window(lua_State *L, int honey_index)
 	hs_create_table(L,
 		hs_str_cfunc("create", window_create),
 		hs_str_cfunc("destroy", window_destroy),
+		hs_str_cfunc("makeContextCurrent", window_make_context_current),
 		hs_str_cfunc("shouldClose", window_should_close),
-		hs_str_cfunc("pollEvents", window_poll_events)
+		hs_str_cfunc("pollEvents", window_poll_events),
+		hs_str_cfunc("swapBuffers", window_swap_buffers),
 	);
 	lua_setfield(L, honey_index, "window");
 }
@@ -46,6 +50,16 @@ int window_destroy(lua_State *L)
 }
 
 
+int window_make_context_current(lua_State *L)
+{
+	void *ptr;
+	hs_parse_args(L, hs_light(ptr));
+	GLFWwindow *win = ptr;
+	glfwMakeContextCurrent(win);
+	return 0;
+}
+
+
 int window_should_close(lua_State *L)
 {
 	void *ptr;
@@ -61,3 +75,13 @@ int window_poll_events(lua_State *L)
 	glfwPollEvents();
 	return 0;
 }
+
+
+int window_swap_buffers(lua_State *L)
+{
+	void *ptr;
+	hs_parse_args(L, hs_light(ptr));
+	GLFWwindow *win = ptr;
+	glfwSwapBuffers(win);
+	return 0;
+}