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8 posts
#10896
opengl
Edited by adekto on
hi i have been trying to run modern gl for couple days but had no luck

but someone on opengl irc helped me out and to never have to deal with this mess again here's the code
(i started from the original game demo)

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#import "fmt.odin";
#import "math.odin";
#import "os.odin";
#import gl "opengl.odin";
#import win32 "sys/windows.odin";

main :: proc(){
	run();
}

win32_print_last_error :: proc() {
	err_code := cast(int)win32.GetLastError();
	if err_code != 0 {
		fmt.println("GetLastError: %", err_code);
	}
}

// Yuk!
to_c_string :: proc(s: string) -> []u8 {
	c_str := new_slice(u8, s.count+1);
	copy(c_str, cast([]byte)s);
	c_str[s.count] = 0;
	return c_str;
}


Window :: struct {
	width: int,
	height:      int,
	wc:                 win32.WNDCLASSEXA,
	dc:                 win32.HDC,
	hwnd:               win32.HWND,
	opengl_context: win32.HGLRC,
	 rc: win32.HGLRC,
	c_title:            []u8
}

make_window :: proc(title: string, msg, height: int, window_proc: win32.WNDPROC) -> (Window, bool) {
	using win32;

	w: Window;
	w.width, w.height = msg, height;

	class_name := "Win32-Odin-Window\x00";
	c_class_name := class_name.data;
	if title[title.count-1] != 0 {
		w.c_title = to_c_string(title);
	} else {
		w.c_title = cast([]u8)title;
	}

	instance := GetModuleHandleA(nil);

	w.wc = WNDCLASSEXA{
		size       = cast(u32)size_of(WNDCLASSEXA),
		style      = CS_VREDRAW | CS_HREDRAW,
		instance   = cast(HINSTANCE)instance,
		class_name = c_class_name,
		wnd_proc   = window_proc,
	};

	if RegisterClassExA(^w.wc) == 0 {
		win32_print_last_error();
		return w, false;
	}

	w.hwnd = CreateWindowExA(0,
	                         c_class_name, w.c_title.data,
	                         WS_VISIBLE | WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX,
	                         CW_USEDEFAULT, CW_USEDEFAULT,
	                         cast(i32)w.width, cast(i32)w.height,
	                         nil, nil, instance, nil);

	if w.hwnd == nil {
		win32_print_last_error();
		return w, false;
	}

	w.dc = GetDC(w.hwnd);

	{
		pfd := PIXELFORMATDESCRIPTOR{
			size         = cast(u32)size_of(PIXELFORMATDESCRIPTOR),
			version      = 1,
			flags        = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
			pixel_type   = PFD_TYPE_RGBA,
			color_bits   = 32,
			alpha_bits   = 8,
			depth_bits   = 24,
			stencil_bits = 8,
			layer_type   = PFD_MAIN_PLANE,
		};

		SetPixelFormat(w.dc, ChoosePixelFormat(w.dc, ^pfd), nil);
		w.opengl_context = wglCreateContext(w.dc);
		wglMakeCurrent(w.dc, w.opengl_context);

		attribs := [8]i32{
			//WGL_SAMPLES_ARB, 4,
			WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
			WGL_CONTEXT_MINOR_VERSION_ARB, 3,
			WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
			0, // NOTE(bill): tells the proc that this is the end of attribs
		};

		wglCreateContextAttribsARB := cast(wglCreateContextAttribsARBType)wglGetProcAddress((cast(string)"wglCreateContextAttribsARB\x00").data);
		w.rc = wglCreateContextAttribsARB(w.dc, nil, ^attribs[0]);
		wglMakeCurrent(w.dc, w.rc);
		SwapBuffers(w.dc);
	}

	return w, true;
}

destroy_window :: proc(w: ^Window) {
	free(w.c_title.data);
}

display_window :: proc(w: ^Window) {
	win32.SwapBuffers(w.dc);
}


run :: proc() {
	using win32;
	using math;

	win32_procA :: proc(hwnd: win32.HWND, msg: u32, wparam: win32.WPARAM, lparam: win32.LPARAM) -> win32.LRESULT #no_inline {
		if msg == WM_DESTROY || msg == WM_CLOSE || msg == WM_QUIT {
			os.exit(0);
			return 0;
		}
		return DefWindowProcA(hwnd, msg, wparam, lparam);
	}
	win32_proc := cast(WNDPROC)win32_procA;
	window, window_success := make_window("Odin gl Demo", 500, 450, win32_proc);
	if !window_success {
		return;
	}
	defer destroy_window(^window);

	//gl
	gl.init();

	vao : u32;
	gl.GenVertexArrays(1, ^vao);
	gl.BindVertexArray(vao);

	vertexData := []f32{
		-1,-1, 0,
		 1,-1, 0,
		 0, 1, 0
	};

	vertexBuffer : u32;
	gl.GenBuffers(1, ^vertexBuffer);
	gl.BindBuffer(gl.ARRAY_BUFFER, vertexBuffer);
	gl.BufferData(gl.ARRAY_BUFFER, 9*size_of(f32)/* <-is there a better way?*/, vertexData.data, gl.STATIC_DRAW);

	//loop
	running := true;
	for running {
		msg: MSG;
		for PeekMessageA(^msg, nil, 0, 0, PM_REMOVE) > 0 {
			if msg.message == WM_QUIT {
				running = false;
			}
			TranslateMessage(^msg);
			DispatchMessageA(^msg);
		}
		//---------------------//
		gl.EnableVertexAttribArray(0);
		gl.BindBuffer(gl.ARRAY_BUFFER, vertexBuffer);
		gl.VertexAttribPointer(0,3,gl.FLOAT,gl.FALSE,0,nil);
		gl.DrawArrays(gl.TRIANGLES,0,3);
		gl.DisableVertexAttribArray(0);

		//---------------------//
		display_window(^window);
	}
}
Mārtiņš Možeiko
2562 posts / 2 projects
#10901
opengl
For C code to set up modern GL context you can use this are reference: https://git.handmade.network/snippets/17
8 posts
#10904
opengl
Edited by adekto on
cool, il see what i can translate in next versions
i added shaders to it now but there are some aditions and changes i had to made to the opengl.odin file to make it work, might be doing some stuff wrong i will also include my modified gl file, i dont want to bother Bill about it since im probably missing stuff or doing the pointers wrong

hello triangle
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#import "fmt.odin";
#import "math.odin";
#import "os.odin";
#import gl "opengl.odin";
#import win32 "sys/windows.odin";

main :: proc(){
	run();
}

win32_print_last_error :: proc() {
	err_code := cast(int)win32.GetLastError();
	if err_code != 0 {
		fmt.println("GetLastError: %", err_code);
	}
}

// Yuk!
to_c_string :: proc(s: string) -> []u8 {
	c_str := new_slice(u8, s.count+1);
	copy(c_str, cast([]byte)s);
	c_str[s.count] = 0;
	return c_str;
}


Window :: struct {
	width: int,
	height:      int,
	wc:                 win32.WNDCLASSEXA,
	dc:                 win32.HDC,
	hwnd:               win32.HWND,
	opengl_context: win32.HGLRC,
	 rc: win32.HGLRC,
	c_title:            []u8
}

make_window :: proc(title: string, msg, height: int, window_proc: win32.WNDPROC) -> (Window, bool) {
	using win32;

	w: Window;
	w.width, w.height = msg, height;

	class_name := "Win32-Odin-Window\x00";
	c_class_name := class_name.data;
	if title[title.count-1] != 0 {
		w.c_title = to_c_string(title);
	} else {
		w.c_title = cast([]u8)title;
	}

	instance := GetModuleHandleA(nil);

	w.wc = WNDCLASSEXA{
		size       = cast(u32)size_of(WNDCLASSEXA),
		style      = CS_VREDRAW | CS_HREDRAW,
		instance   = cast(HINSTANCE)instance,
		class_name = c_class_name,
		wnd_proc   = window_proc,
	};

	if RegisterClassExA(^w.wc) == 0 {
		win32_print_last_error();
		return w, false;
	}

	w.hwnd = CreateWindowExA(0,
	                         c_class_name, w.c_title.data,
	                         WS_VISIBLE | WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX,
	                         CW_USEDEFAULT, CW_USEDEFAULT,
	                         cast(i32)w.width, cast(i32)w.height,
	                         nil, nil, instance, nil);

	if w.hwnd == nil {
		win32_print_last_error();
		return w, false;
	}

	w.dc = GetDC(w.hwnd);

	{
		pfd := PIXELFORMATDESCRIPTOR{
			size         = cast(u32)size_of(PIXELFORMATDESCRIPTOR),
			version      = 1,
			flags        = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
			pixel_type   = PFD_TYPE_RGBA,
			color_bits   = 32,
			alpha_bits   = 8,
			depth_bits   = 24,
			stencil_bits = 8,
			layer_type   = PFD_MAIN_PLANE,
		};

		SetPixelFormat(w.dc, ChoosePixelFormat(w.dc, ^pfd), nil);
		w.opengl_context = wglCreateContext(w.dc);
		wglMakeCurrent(w.dc, w.opengl_context);

		attribs := [8]i32{
			//WGL_SAMPLES_ARB, 4,
			WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
			WGL_CONTEXT_MINOR_VERSION_ARB, 3,
			WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
			0, // NOTE(bill): tells the proc that this is the end of attribs
		};

		wglCreateContextAttribsARB := cast(wglCreateContextAttribsARBType)wglGetProcAddress((cast(string)"wglCreateContextAttribsARB\x00").data);
		w.rc = wglCreateContextAttribsARB(w.dc, nil, ^attribs[0]);
		wglMakeCurrent(w.dc, w.rc);
		SwapBuffers(w.dc);
	}

	return w, true;
}

destroy_window :: proc(w: ^Window) {
	free(w.c_title.data);
}

display_window :: proc(w: ^Window) {
	win32.SwapBuffers(w.dc);
}


run :: proc() {
	using win32;
	using math;

	win32_procA :: proc(hwnd: win32.HWND, msg: u32, wparam: win32.WPARAM, lparam: win32.LPARAM) -> win32.LRESULT #no_inline {
		if msg == WM_DESTROY || msg == WM_CLOSE || msg == WM_QUIT {
			os.exit(0);
			return 0;
		}
		return DefWindowProcA(hwnd, msg, wparam, lparam);
	}
	win32_proc := cast(WNDPROC)win32_procA;
	window, window_success := make_window("Odin gl Demo", 500, 450, win32_proc);
	if !window_success {
		return;
	}
	defer destroy_window(^window);

	//gl
	gl.init();

	vao : u32;
	gl.GenVertexArrays(1, ^vao);
	gl.BindVertexArray(vao);



	vertexData := []f32{
		-1,-1, 0,/*<-vert color->*/1.0, 0.0, 0.0,
		 1,-1, 0,/*<-vert color->*/0.0, 1.0, 0.0,
		 0, 1, 0,/*<-vert color->*/0.0, 0.0, 1.0
	};

	vbo : u32;
	gl.GenBuffers(1, ^vbo);
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo);
	gl.BufferData(gl.ARRAY_BUFFER, vertexData.count*size_of(f32)/* <-is there a better way?*/, vertexData.data, gl.STATIC_DRAW);

	
	to_c_string :: proc(s: string) -> []byte {
		// no better way to do it :(
		c_str := new_slice(byte, s.count+1);
		copy(c_str, cast([]byte)s);
		c_str[s.count] = 0;
		return c_str;
	}
	check_shader :: proc(shader:u32){
		//check for shader error
		status :i32;
		gl.GetShaderiv(shader,gl.COMPILE_STATUS, ^status);
		fmt.println(status);
		buffer :=[512]byte{};
		gl.GetShaderInfoLog(shader,512,nil,^buffer[0]);
		if status == 0 {
			for i in buffer{
				fmt.printf("%c ",buffer[i]); //got no clue what its spitting out
			}
		}
		
		
	}

	//vertex shader
	vert := to_c_string("#version 430 core \n layout(location=0) in vec3 position; \n in vec3 color; \n out vec3 Color; \n void main(){ \n Color = color; \n gl_Position.xyz = position; \n gl_Position.w = 1; }");
	vertx := ^vert[0]; //not very eligant, any beter ways?
	vertShader := gl.CreateShader(gl.VERTEX_SHADER);
	gl.ShaderSource(vertShader, 1, ^vertx, nil);
	gl.CompileShader(vertShader);
	
	check_shader(vertShader);

	//fragment shader
	frag := to_c_string("#version 430 core \n uniform vec3 triangleColor; \n in vec3 Color; \n void main(){ \n  gl_FragColor = vec4(Color+triangleColor, 1.0); }");
	fragm := ^frag[0];
	fragShader := gl.CreateShader(gl.FRAGMENT_SHADER);
	gl.ShaderSource(fragShader, 1, ^fragm, nil);
	gl.CompileShader(fragShader);

	check_shader(fragShader);

	//program
	program := gl.CreateProgram();
	gl.AttachShader(program, vertShader);
	gl.AttachShader(program, fragShader);
	gl.LinkProgram(program);
	gl.UseProgram(program);

	colorptr := to_c_string("triangleColor");
	colorptrptr := colorptr[0];
	//changeColor := gl.GetUniformLocation(program, ^colorptrptr);
	//fmt.println(changeColor);
	changeColor := gl.GetUniformLocation(program, to_c_string("triangleColor"));
	gl.Uniform3f(changeColor, 0.0 ,0.5 ,0.1 );

	posAttrib := gl.GetAttribLocation(program, to_c_string("position"));
	gl.EnableVertexAttribArray(posAttrib);
	gl.VertexAttribPointer(posAttrib, 3 , gl.FLOAT, gl.FALSE, 6*size_of(f32), 0);

	colAttrib := gl.GetAttribLocation(program, to_c_string("color"));
	gl.EnableVertexAttribArray(colAttrib);
	
	gl.VertexAttribPointer(colAttrib, 3 , gl.FLOAT, gl.FALSE, 6*size_of(f32), 3*size_of(f32));


	//loop
	running := true;
	for running {
		msg: MSG;
		for PeekMessageA(^msg, nil, 0, 0, PM_REMOVE) > 0 {
			if msg.message == WM_QUIT {
				running = false;
			}
			TranslateMessage(^msg);
			DispatchMessageA(^msg);
		}
		gl.ClearColor(0,0.1,0.1,0);
		gl.Clear(gl.COLOR_BUFFER_BIT);
		//---------------------//
		//gl.EnableVertexAttribArray(0);
		//gl.BindBuffer(gl.ARRAY_BUFFER, vbo);
		//gl.VertexAttribPointer(0,3,gl.FLOAT,gl.FALSE,0,nil);
		gl.DrawArrays(gl.TRIANGLES,0,3);
		//gl.DisableVertexAttribArray(0);

		//---------------------//
		display_window(^window);
	}
}


opengl.odin
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#foreign_system_library lib "opengl32.lib" when ODIN_OS == "windows";
#import win32 "sys/windows.odin" when ODIN_OS == "windows";
#load "opengl_constants.odin";

Clear         :: proc(mask: u32)                                #foreign lib "glClear";
ClearColor    :: proc(r, g, b, a: f32)                          #foreign lib "glClearColor";
Begin         :: proc(mode: i32)                                #foreign lib "glBegin";
End           :: proc()                                         #foreign lib "glEnd";
Finish        :: proc()                                         #foreign lib "glFinish";
BlendFunc     :: proc(sfactor, dfactor: i32)                    #foreign lib "glBlendFunc";
Enable        :: proc(cap: i32)                                 #foreign lib "glEnable";
Disable       :: proc(cap: i32)                                 #foreign lib "glDisable";
GenTextures   :: proc(count: i32, result: ^u32)                 #foreign lib "glGenTextures";
DeleteTextures:: proc(count: i32, result: ^u32)                 #foreign lib "glDeleteTextures";
TexParameteri :: proc(target, pname, param: i32)                #foreign lib "glTexParameteri";
TexParameterf :: proc(target: i32, pname: i32, param: f32)      #foreign lib "glTexParameterf";
BindTexture   :: proc(target: i32, texture: u32)                #foreign lib "glBindTexture";
LoadIdentity  :: proc()                                         #foreign lib "glLoadIdentity";
Viewport      :: proc(x, y, width, height: i32)                 #foreign lib "glViewport";
Ortho         :: proc(left, right, bottom, top, near, far: f64) #foreign lib "glOrtho";
Color3f       :: proc(r, g, b: f32)                             #foreign lib "glColor3f";
Vertex3f      :: proc(x, y, z: f32)                             #foreign lib "glVertex3f";
TexCoord2f    :: proc(x,y: f32)									#foreign lib "glTexCoord2f";
TexImage2D    :: proc(target, level, internal_format,
                      width, height, border,
                      format, _type: i32, pixels: []f32) #foreign lib "glTexImage2D";

GetError    :: proc() -> i32            #foreign lib "glGetError";
GetString   :: proc(name: i32) -> ^byte #foreign lib "glGetString";
GetIntegerv :: proc(name: i32, v: ^i32) #foreign lib "glGetIntegerv";


string_data :: proc(s: string) -> ^u8 #inline { return ^s[0]; }

_libgl := win32.LoadLibraryA(string_data("opengl32.dll\x00"));

GetProcAddress :: proc(name: string) -> proc() #cc_c {
	assert(name[name.count-1] == 0);
	res := win32.wglGetProcAddress(name.data);
	if res == nil {
		res = win32.GetProcAddress(_libgl, name.data);
	}
	return res;
}

GenBuffers:       proc(count: i32, buffers: ^u32) #cc_c;
GenVertexArrays:  proc(count: i32, buffers: ^u32) #cc_c;
GenSamplers:      proc(count: i32, buffers: ^u32) #cc_c;
BindBuffer:       proc(target: i32, buffer: u32) #cc_c;
BindVertexArray:  proc(buffer: u32) #cc_c;
BindSampler:      proc(position: i32, sampler: u32) #cc_c;
BufferData:       proc(target: i32, size: int, data: rawptr, usage: i32) #cc_c;
BufferSubData:    proc(target: i32, offset, size: int, data: rawptr) #cc_c;

DrawArrays:       proc(mode, first: i32, count: u32) #cc_c;
DrawElements:     proc(mode: i32, count: u32, type_: i32, indices: rawptr) #cc_c;

MapBuffer:        proc(target, access: i32) -> rawptr #cc_c;
UnmapBuffer:      proc(target: i32) #cc_c;

VertexAttribPointer:  proc(index: u32, size, type_: i32, normalized: i32, stride: u32, pointer: int) #cc_c;
EnableVertexAttribArray:  proc(index: u32) #cc_c;
DisableVertexAttribArray: proc(index: u32) #cc_c;
GetAttribLocation: proc(program: u32, name: []byte) -> u32 #cc_c;

CreateShader:   proc(shader_type: i32) -> u32 #cc_c;
ShaderSource:   proc(shader: u32, count: u32, str: ^^byte, length: ^i32) #cc_c;
CompileShader:  proc(shader: u32) #cc_c;
CreateProgram:  proc() -> u32 #cc_c;
AttachShader:   proc(program, shader: u32) #cc_c;
DetachShader:   proc(program, shader: u32) #cc_c;
DeleteShader:   proc(shader:  u32) #cc_c;
LinkProgram:    proc(program: u32) #cc_c;
UseProgram:     proc(program: u32) #cc_c;
DeleteProgram:  proc(program: u32) #cc_c;


GetShaderiv:        proc(shader:  u32, pname: i32, params: ^i32) #cc_c;
GetProgramiv:       proc(program: u32, pname: i32, params: ^i32) #cc_c;
GetShaderInfoLog:   proc(shader:  u32, max_length: u32, length: ^u32, info_long: ^byte) #cc_c;
GetProgramInfoLog:  proc(program: u32, max_length: u32, length: ^u32, info_long: ^byte) #cc_c;

ActiveTexture:   proc(texture: i32) #cc_c;
GenerateMipmap:  proc(target:  i32) #cc_c;

SamplerParameteri:     proc(sampler: u32, pname: i32, param: i32) #cc_c;
SamplerParameterf:     proc(sampler: u32, pname: i32, param: f32) #cc_c;
SamplerParameteriv:    proc(sampler: u32, pname: i32, params: ^i32) #cc_c;
SamplerParameterfv:    proc(sampler: u32, pname: i32, params: ^f32) #cc_c;
SamplerParameterIiv:   proc(sampler: u32, pname: i32, params: ^i32) #cc_c;
SamplerParameterIuiv:  proc(sampler: u32, pname: i32, params: ^u32) #cc_c;


Uniform1i:         proc(loc: i32, v0: i32) #cc_c;
Uniform2i:         proc(loc: i32, v0, v1: i32) #cc_c;
Uniform3i:         proc(loc: i32, v0, v1, v2: i32) #cc_c;
Uniform4i:         proc(loc: i32, v0, v1, v2, v3: i32) #cc_c;
Uniform1f:         proc(loc: i32, v0: f32) #cc_c;
Uniform2f:         proc(loc: i32, v0, v1: f32) #cc_c;
Uniform3f:         proc(loc: i32, v0, v1, v2: f32) #cc_c;
Uniform4f:         proc(loc: i32, v0, v1, v2, v3: f32) #cc_c;
UniformMatrix4fv:  proc(loc: i32, count: u32, transpose: i32, value: ^f32) #cc_c;

GetUniformLocation:  proc(program: u32, name: []byte) -> i32 #cc_c;

init :: proc() {
	set_proc_address :: proc(p: rawptr, name: string) #inline { (cast(^(proc() #cc_c))p)^ = GetProcAddress(name); }

	set_proc_address(^GenBuffers,      "glGenBuffers\x00");
	set_proc_address(^GenVertexArrays, "glGenVertexArrays\x00");
	set_proc_address(^GenSamplers,     "glGenSamplers\x00");
	set_proc_address(^BindBuffer,      "glBindBuffer\x00");
	set_proc_address(^BindSampler,     "glBindSampler\x00");
	set_proc_address(^BindVertexArray, "glBindVertexArray\x00");
	set_proc_address(^BufferData,      "glBufferData\x00");
	set_proc_address(^BufferSubData,   "glBufferSubData\x00");

	set_proc_address(^DrawArrays,      "glDrawArrays\x00");
	set_proc_address(^DrawElements,    "glDrawElements\x00");

	set_proc_address(^MapBuffer,   "glMapBuffer\x00");
	set_proc_address(^UnmapBuffer, "glUnmapBuffer\x00");

	set_proc_address(^VertexAttribPointer,     "glVertexAttribPointer\x00");
	set_proc_address(^EnableVertexAttribArray, "glEnableVertexAttribArray\x00");
	set_proc_address(^DisableVertexAttribArray, "glDisableVertexAttribArray\x00");
	set_proc_address(^GetAttribLocation, "glGetAttribLocation\x00");

	set_proc_address(^CreateShader,  "glCreateShader\x00");
	set_proc_address(^ShaderSource,  "glShaderSource\x00");
	set_proc_address(^CompileShader, "glCompileShader\x00");
	set_proc_address(^CreateProgram, "glCreateProgram\x00");
	set_proc_address(^AttachShader,  "glAttachShader\x00");
	set_proc_address(^DetachShader,  "glDetachShader\x00");
	set_proc_address(^DeleteShader,  "glDeleteShader\x00");
	set_proc_address(^LinkProgram,   "glLinkProgram\x00");
	set_proc_address(^UseProgram,    "glUseProgram\x00");
	set_proc_address(^DeleteProgram, "glDeleteProgram\x00");

	set_proc_address(^GetShaderiv,       "glGetShaderiv\x00");
	set_proc_address(^GetProgramiv,      "glGetProgramiv\x00");
	set_proc_address(^GetShaderInfoLog,  "glGetShaderInfoLog\x00");
	set_proc_address(^GetProgramInfoLog, "glGetProgramInfoLog\x00");

	set_proc_address(^ActiveTexture,  "glActiveTexture\x00");
	set_proc_address(^GenerateMipmap, "glGenerateMipmap\x00");

	set_proc_address(^Uniform1i, "glUniform1i\x00");
	set_proc_address(^Uniform2i, "glUniform2i\x00");
	set_proc_address(^Uniform3i, "glUniform3i\x00");
	set_proc_address(^Uniform4i, "glUniform4i\x00");
	set_proc_address(^Uniform1f, "glUniform1f\x00");
	set_proc_address(^Uniform2f, "glUniform2f\x00");
	set_proc_address(^Uniform3f, "glUniform3f\x00");
	set_proc_address(^Uniform4f, "glUniform4f\x00");
	set_proc_address(^UniformMatrix4fv, "glUniformMatrix4fv\x00");

	set_proc_address(^GetUniformLocation, "glGetUniformLocation\x00");
	
	set_proc_address(^SamplerParameteri,    "glSamplerParameteri\x00");
	set_proc_address(^SamplerParameterf,    "glSamplerParameterf\x00");
	set_proc_address(^SamplerParameteriv,   "glSamplerParameteriv\x00");
	set_proc_address(^SamplerParameterfv,   "glSamplerParameterfv\x00");
	set_proc_address(^SamplerParameterIiv,  "glSamplerParameterIiv\x00");
	set_proc_address(^SamplerParameterIuiv, "glSamplerParameterIuiv\x00");
}
8 posts
#10917
opengl
currently stuck cant seem to get texture to display also drawElements is cousing crashes not sure what exactly is going wrong since it compiles

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#import "fmt.odin";
#import "math.odin";
#import "os.odin";
#import gl "opengl.odin";
#import win32 "sys/windows.odin";

main :: proc(){
	run();
}

win32_print_last_error :: proc() {
	err_code := cast(int)win32.GetLastError();
	if err_code != 0 {
		fmt.println("GetLastError: %", err_code);
	}
}

// Yuk!
to_c_string :: proc(s: string) -> []u8 {
	c_str := new_slice(u8, s.count+1);
	copy(c_str, cast([]byte)s);
	c_str[s.count] = 0;
	return c_str;
}


Window :: struct {
	width: int,
	height:      int,
	wc:                 win32.WNDCLASSEXA,
	dc:                 win32.HDC,
	hwnd:               win32.HWND,
	opengl_context: win32.HGLRC,
	 rc: win32.HGLRC,
	c_title:            []u8
}

make_window :: proc(title: string, msg, height: int, window_proc: win32.WNDPROC) -> (Window, bool) {
	using win32;

	w: Window;
	w.width, w.height = msg, height;

	class_name := "Win32-Odin-Window\x00";
	c_class_name := class_name.data;
	if title[title.count-1] != 0 {
		w.c_title = to_c_string(title);
	} else {
		w.c_title = cast([]u8)title;
	}

	instance := GetModuleHandleA(nil);

	w.wc = WNDCLASSEXA{
		size       = cast(u32)size_of(WNDCLASSEXA),
		style      = CS_VREDRAW | CS_HREDRAW,
		instance   = cast(HINSTANCE)instance,
		class_name = c_class_name,
		wnd_proc   = window_proc,
	};

	if RegisterClassExA(^w.wc) == 0 {
		win32_print_last_error();
		return w, false;
	}

	w.hwnd = CreateWindowExA(0,
	                         c_class_name, w.c_title.data,
	                         WS_VISIBLE | WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX,
	                         CW_USEDEFAULT, CW_USEDEFAULT,
	                         cast(i32)w.width, cast(i32)w.height,
	                         nil, nil, instance, nil);

	if w.hwnd == nil {
		win32_print_last_error();
		return w, false;
	}

	w.dc = GetDC(w.hwnd);

	{
		pfd := PIXELFORMATDESCRIPTOR{
			size         = cast(u32)size_of(PIXELFORMATDESCRIPTOR),
			version      = 1,
			flags        = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
			pixel_type   = PFD_TYPE_RGBA,
			color_bits   = 32,
			alpha_bits   = 8,
			depth_bits   = 24,
			stencil_bits = 8,
			layer_type   = PFD_MAIN_PLANE,
		};

		SetPixelFormat(w.dc, ChoosePixelFormat(w.dc, ^pfd), nil);
		w.opengl_context = wglCreateContext(w.dc);
		wglMakeCurrent(w.dc, w.opengl_context);

		attribs := [8]i32{
			//WGL_SAMPLES_ARB, 4,
			WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
			WGL_CONTEXT_MINOR_VERSION_ARB, 3,
			WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
			0, // NOTE(bill): tells the proc that this is the end of attribs
		};

		wglCreateContextAttribsARB := cast(wglCreateContextAttribsARBType)wglGetProcAddress((cast(string)"wglCreateContextAttribsARB\x00").data);
		w.rc = wglCreateContextAttribsARB(w.dc, nil, ^attribs[0]);
		wglMakeCurrent(w.dc, w.rc);
		SwapBuffers(w.dc);
	}

	return w, true;
}

destroy_window :: proc(w: ^Window) {
	free(w.c_title.data);
}

display_window :: proc(w: ^Window) {
	win32.SwapBuffers(w.dc);
}


run :: proc() {
	using win32;
	using math;

	win32_procA :: proc(hwnd: win32.HWND, msg: u32, wparam: win32.WPARAM, lparam: win32.LPARAM) -> win32.LRESULT #no_inline {
		if msg == WM_DESTROY || msg == WM_CLOSE || msg == WM_QUIT {
			os.exit(0);
			return 0;
		}
		return DefWindowProcA(hwnd, msg, wparam, lparam);
	}
	win32_proc := cast(WNDPROC)win32_procA;
	window, window_success := make_window("Odin gl Demo", 500, 450, win32_proc);
	if !window_success {
		return;
	}
	defer destroy_window(^window);

	//gl
	gl.init();

	vao : u32;
	gl.GenVertexArrays(1, ^vao);
	gl.BindVertexArray(vao);



	vertexData := []f32{
		-1,-1, 0,/*<-vert color->*/1.0, 0.0, 0.0, /*texture->*/ 1,1,
		 1,-1, 0,/*<-vert color->*/0.0, 1.0, 0.0, /*texture->*/ 1,0,
		 0, 1, 0,/*<-vert color->*/0.0, 0.0, 1.0, /*texture->*/ 0,0
	};

	vbo : u32;
	gl.GenBuffers(1, ^vbo);
	gl.BindBuffer(gl.ARRAY_BUFFER, vbo);
	gl.BufferData(gl.ARRAY_BUFFER, vertexData.count*size_of(f32)/* <-is there a better way?*/, vertexData.data, gl.STATIC_DRAW);

	
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.MIRRORED_REPEAT);
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.MIRRORED_REPEAT);
	
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
	gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);

	pixels :=[]f32 {
		1.0, 0.0, 0.0,  1.0, 1.0, 1.0,
		1.0, 1.0, 1.0,  1.0, 0.0, 0.0
	};
	texture : u32;
	gl.GenTextures(1,^texture);
	gl.BindTexture(gl.TEXTURE_2D,texture);
	gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGB, 3, 3, 0, gl.RGB, gl.FLOAT , pixels);


	to_c_string :: proc(s: string) -> []byte {
		// no better way to do it :(
		c_str := new_slice(byte, s.count+1);
		copy(c_str, cast([]byte)s);
		c_str[s.count] = 0;
		return c_str;
	}
	check_shader :: proc(shader:u32){
		//check for shader error
		status :i32;
		gl.GetShaderiv(shader,gl.COMPILE_STATUS, ^status);
		fmt.println(status);
		buffer :=[512]byte{};
		gl.GetShaderInfoLog(shader,512,nil,^buffer[0]);
		if status == 0 {
			for i in buffer{
				fmt.printf("%c ",buffer[i]); //got no clue what its spitting out
			}
		}
		
		
	}

	//vertex shader
	vert := to_c_string("#version 430 core \n layout(location=0) in vec3 position; \n layout(location=1) in vec3 color; \n layout(location=2) in vec2 texCoord; \n out vec3 Color; \n out vec2 TexCoord; \n void main(){ \n Color = color; \n TexCoord = texCoord; \n gl_Position.xyz = position; \n gl_Position.w = 1; }");
	vertx := ^vert[0]; //not very eligant, any beter ways?
	vertShader := gl.CreateShader(gl.VERTEX_SHADER);
	gl.ShaderSource(vertShader, 1, ^vertx, nil);
	gl.CompileShader(vertShader);
	
	check_shader(vertShader);

	//fragment shader
	frag := to_c_string("#version 430 core \n uniform vec3 triangleColor; \n in vec3 Color; \n in vec2 TexCoord; \n uniform sampler2D Texture; \n void main(){ \n  gl_FragColor =  texture(Texture, TexCoord); //vec4(Color+triangleColor, 1.0); \n }");
	fragm := ^frag[0];
	fragShader := gl.CreateShader(gl.FRAGMENT_SHADER);
	gl.ShaderSource(fragShader, 1, ^fragm, nil);
	gl.CompileShader(fragShader);

	check_shader(fragShader);

	//program
	program := gl.CreateProgram();
	gl.AttachShader(program, vertShader);
	gl.AttachShader(program, fragShader);
	gl.LinkProgram(program);
	gl.UseProgram(program);

	colorptr := to_c_string("triangleColor");
	colorptrptr := colorptr[0];
	changeColor := gl.GetUniformLocation(program, to_c_string("triangleColor"));
	gl.Uniform3f(changeColor, 0.0 ,0.5 ,0.1 );

	Texture := gl.GetUniformLocation(program, to_c_string("Texture"));
	gl.Uniform1i(Texture, cast(i32)texture);

	posAttrib := gl.GetAttribLocation(program, to_c_string("position"));
	gl.EnableVertexAttribArray(posAttrib);
	gl.VertexAttribPointer(posAttrib, 3 , gl.FLOAT, gl.FALSE, 8*size_of(f32), 0);

	colAttrib := gl.GetAttribLocation(program, to_c_string("color"));
	gl.EnableVertexAttribArray(colAttrib);
	gl.VertexAttribPointer(colAttrib, 3 , gl.FLOAT, gl.FALSE, 8*size_of(f32), 3*size_of(f32));

	texAttrib := gl.GetAttribLocation(program, to_c_string("texCoord"));
	gl.EnableVertexAttribArray(texAttrib);
	gl.VertexAttribPointer(texAttrib, 2 , gl.FLOAT, gl.FALSE, 8*size_of(f32), 6*size_of(f32));


	//loop
	running := true;
	for running {
		msg: MSG;
		for PeekMessageA(^msg, nil, 0, 0, PM_REMOVE) > 0 {
			if msg.message == WM_QUIT {
				running = false;
			}
			TranslateMessage(^msg);
			DispatchMessageA(^msg);
		}
		gl.ClearColor(0,0.1,0.1,0);
		gl.Clear(gl.COLOR_BUFFER_BIT);
		//---------------------//
		gl.BindTexture(gl.TEXTURE_2D,texture);
		gl.BindVertexArray(vao);
		gl.DrawArrays(gl.TRIANGLES,0,3);
		//gl.DrawElements(gl.TRIANGLES,3,gl.UNSIGNED_INT /*crashes exe*/ , nil);
		gl.BindVertexArray(0);

		//---------------------//
		display_window(^window);
	}
}
511 posts
#10918
opengl
your pixel data describes a 2x2 texture but you tell opengl it's a 3x3.

Also you should pass pixels.data instead of pixels.
8 posts
#10922
opengl
oh ok, well fixed that but there still allot wrong
i got no idea what im doing at this point :p
511 posts
#10923
opengl
most likely not the problem but you can pas the length of the shader sources explicitly so you don't need to null terminate them:

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	vert := "#version 430 core \n layout(location=0) in vec3 position; \n layout(location=1) in vec3 color; \n layout(location=2) in vec2 texCoord; \n out vec3 Color; \n out vec2 TexCoord; \n void main(){ \n Color = color; \n TexCoord = texCoord; \n gl_Position.xyz = position; \n gl_Position.w = 1; }";
	vertx := vert.data; 
        length := vert.count; 
	vertShader := gl.CreateShader(gl.VERTEX_SHADER);
	gl.ShaderSource(vertShader, 1, ^vert.vertx, ^vert.count);
	gl.CompileShader(vertShader);


also after linkprogram you should check it analogue to checking the shader but instead with glGetProgramiv.
Mārtiņš Možeiko
2562 posts / 2 projects
#10929
opengl
Edited by Mārtiņš Možeiko on
DrawElements crashes because you have not bound index buffer (GL_ELEMENT_ARRAY_BUFFER). It tries to deference array you passed which is NULL.

Also - add error checking (glGetError, GL_LINK_STATUS). And ideally use GL_ARB_debug_output extension. It should tell you this error (pointer NULL and no IB bound) in easy to understand message.
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