Created
September 14, 2017 19:02
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#library "libc" | |
#import github("vdka/gl") | |
#import github("vdka/glfw") | |
#import github("kai-language/stdlib") | |
#foreign libc { | |
printf :: (fmt: *u8, args: #cvargs ..any) -> i32 | |
exit :: (exitcode: i32) -> void | |
} | |
panic :: fn(msg: string) -> void { | |
printf(msg.raw) | |
exit(1) | |
} | |
//glfwErrorCallback :: fn(error: i32, desc: *u8) -> void { | |
// printf("Error code %d:\n\t%s\n", error, desc) | |
//} | |
initGlfw :: fn() -> *glfw.Window, bool { | |
//glfw.SetErrorCallback(&glfwErrorCallback) | |
if glfw.Init() == 0 { | |
return nil, false | |
} | |
glfw.WindowHint(glfw.SAMPLES, 4) | |
glfw.WindowHint(glfw.CONTEXT_VERSION_MAJOR, 3) | |
glfw.WindowHint(glfw.CONTEXT_VERSION_MINOR, 3) | |
glfw.WindowHint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE) | |
glfw.WindowHint(glfw.OPENGL_FORWARD_COMPAT, 1) | |
window := glfw.CreateWindow(1280, 720, "Kai GLFW example".raw, nil, nil) | |
if window == nil { | |
panic("Asdfklasjdf") | |
return nil, false | |
} | |
glfw.MakeContextCurrent(window) | |
return window, true | |
} | |
loadShaders :: fn() -> u32 { | |
vertex_shader_source := " | |
#version 330 core | |
layout(location = 0) in vec3 vertexPosition; | |
uniform mat4 MVP; | |
out vec3 pos; | |
void main() { | |
gl_Position = MVP * vec4(vertexPosition, 1.0); | |
pos = vertexPosition.xyz; | |
} | |
" | |
fragment_shader_source := " | |
#version 330 core | |
in vec3 pos; | |
out vec4 color; | |
uniform float time; | |
void main() { | |
color = vec4(pos.xy, 0.5 + 0.5 * sin(time), 1.0); | |
} | |
" | |
vertex_shader_length := cast(i32) vertex_shader_source.len | |
fragment_shader_length := cast(i32) fragment_shader_source.len | |
vertex_shader_id := gl.CreateShader(gl.VERTEX_SHADER) | |
fragment_shader_id := gl.CreateShader(gl.FRAGMENT_SHADER) | |
gl.ShaderSource(vertex_shader_id, 1, &vertex_shader_source.raw, &vertex_shader_length) | |
gl.ShaderSource(fragment_shader_id, 1, &fragment_shader_source.raw, &fragment_shader_length) | |
gl.CompileShader(vertex_shader_id) | |
gl.CompileShader(fragment_shader_id) | |
program := gl.CreateProgram() | |
gl.AttachShader(program, vertex_shader_id) | |
gl.AttachShader(program, fragment_shader_id) | |
gl.LinkProgram(program) | |
gl.DeleteShader(vertex_shader_id) | |
gl.DeleteShader(fragment_shader_id) | |
return program | |
} | |
createBuffers :: fn() -> u32, u32, u32 { | |
vao: u32 | |
gl.GenVertexArrays(1, &vao) | |
gl.BindVertexArray(vao) | |
// a 2x2x2 cube, using triangle strips and indices | |
cubeVertices := [..]f32 { | |
-1.0, -1.0, 1.0, | |
1.0, -1.0, 1.0, | |
-1.0, 1.0, 1.0, | |
1.0, 1.0, 1.0, | |
-1.0, -1.0, -1.0, | |
1.0, -1.0, -1.0, | |
-1.0, 1.0, -1.0, | |
1.0, 1.0, -1.0, | |
} | |
cubeIndices := [..]u16{ | |
// TRIANGLE_STRIP, 14 indices = 12 triangles | |
0, 1, 2, 3, 7, 1, 5, 4, 7, 6, 2, 4, 0, 1, | |
} | |
vbo: u32 | |
gl.GenBuffers(1, &vbo) | |
gl.BindBuffer(gl.ARRAY_BUFFER, vbo) | |
gl.BufferData(gl.ARRAY_BUFFER, 96, cast(rawptr) &cubeVertices[0], gl.STATIC_DRAW) | |
gl.EnableVertexAttribArray(0) | |
gl.VertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 0, nil) | |
ebo: u32 | |
gl.GenBuffers(1, &ebo) | |
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebo) | |
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, 28, cast(rawptr) &cubeIndices[0], gl.STATIC_DRAW) | |
return vao, vbo, ebo | |
} | |
main :: fn () -> void { | |
window, success := initGlfw() | |
if !success | |
panic("Error with window creation!\n") | |
gl.init(cast((*u8) -> rawptr) glfw.GetProcAddress) | |
program := loadShaders() | |
vao, vbo, ebo := createBuffers() | |
// timings | |
tPrev := glfw.GetTime() | |
frame := 0 | |
res := [2]f32{1280, 720} | |
p := stdlib.perspective(0.785, 1.77, 0.1, 100.0) | |
pos := [vec 3]f32 { 4, 3, 3 } | |
lookPos := [vec 3]f32 { 0, 0, 0 } | |
up := [vec 3]f32 { 0, 1, 0 } | |
v := stdlib.look_at(pos, lookPos, up) | |
m := stdlib.identity_mat() | |
gl.Enable(gl.DEPTH_TEST); | |
gl.ClearColor(0.2, 0.3, 0.4, 1.0); | |
for glfw.WindowShouldClose(window) == glfw.FALSE { | |
tNow := glfw.GetTime() | |
dt := cast(f32) (tNow - tPrev) | |
tPrev = tNow | |
glfw.PollEvents() | |
if glfw.GetKey(window, glfw.KEY_ESCAPE) == glfw.TRUE | |
break | |
MV := stdlib.mul(v, m) | |
MVP := stdlib.mul(p, MV) | |
// Drawing | |
gl.Clear(cast(u32) gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); | |
gl.UseProgram(program) | |
gl.UniformMatrix4fv(gl.GetUniformLocation(program, "MVP".raw), 1, gl.FALSE, &MVP[0][0]) | |
gl.Uniform1f(gl.GetUniformLocation(program, "time".raw), cast(f32) glfw.GetTime()) | |
//gl.Uniform2f(gl.GetUniformLocation(program, "resolution".raw), 1280, 720) | |
gl.BindVertexArray(vao) | |
gl.DrawElements(gl.TRIANGLE_STRIP, 14, gl.UNSIGNED_SHORT, nil) | |
glfw.SwapBuffers(window) | |
} | |
glfw.Terminate() | |
printf("Exiting!\n".raw) | |
} |
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