1 files changed, 171 insertions, 0 deletions
diff --git a/src/shader.rs b/src/shader.rs
new file mode 100644
index 0000000..6bcae3c
--- /dev/null
+++ b/src/shader.rs
@@ -0,0 +1,171 @@
+use std::collections::HashMap;
+
+use glow::HasContext;
+
+use crate::{context, mesh};
+
+const COMMON_VERT: &'static str = include_str!("assets/shaders/common/vert.glsl");
+const COMMON_FRAG: &'static str = include_str!("assets/shaders/common/frag.glsl");
+
+#[derive(Clone)]
+pub struct Shader {
+    pub program: glow::Program,
+    pub uniforms: std::rc::Rc<HashMap<String, glow::UniformLocation>>
+}
+
+impl Shader {
+    pub fn new_nolib(ctx: &context::Context, vsrc: &str, fsrc: &str) -> Self {
+        unsafe {
+            let program = ctx.gl.create_program()
+                .expect("cannot create shader program");
+
+            let vert = ctx.gl.create_shader(glow::VERTEX_SHADER)
+                .expect("cannot create shader");
+            ctx.gl.shader_source(vert, &vsrc);
+            ctx.gl.compile_shader(vert);
+            if !ctx.gl.get_shader_compile_status(vert) {
+                panic!(
+                    "failed to compile vertex shader:\n{}",
+                    ctx.gl.get_shader_info_log(vert)
+                );
+            }
+            ctx.gl.attach_shader(program, vert);
+
+            let frag = ctx.gl.create_shader(glow::FRAGMENT_SHADER)
+                .expect("cannot create shader");
+            ctx.gl.shader_source(frag, &fsrc);
+            ctx.gl.compile_shader(frag);
+            if !ctx.gl.get_shader_compile_status(frag) {
+                panic!(
+                    "failed to compile fragment shader:\n{}",
+                    ctx.gl.get_shader_info_log(frag)
+                );
+            }
+            ctx.gl.attach_shader(program, frag);
+
+            ctx.gl.bind_attrib_location(program, mesh::ATTRIB_VERTEX, "vertex");
+            ctx.gl.bind_attrib_location(program, mesh::ATTRIB_NORMAL, "normal");
+            ctx.gl.bind_attrib_location(program, mesh::ATTRIB_TEXCOORD, "texcoord");
+
+            ctx.gl.link_program(program);
+            if !ctx.gl.get_program_link_status(program) {
+                panic!(
+                    "failed to link shader program:\n{}",
+                    ctx.gl.get_program_info_log(program),
+                );
+            }
+
+            ctx.gl.detach_shader(program, vert);
+            ctx.gl.delete_shader(vert);
+            ctx.gl.detach_shader(program, frag);
+            ctx.gl.delete_shader(frag);
+
+            let mut uniforms = HashMap::new();
+            for index in 0..ctx.gl.get_active_uniforms(program) {
+                if let Some(active) = ctx.gl.get_active_uniform(program, index) {
+                    let loc = ctx.gl.get_uniform_location(program, &active.name)
+                        .expect(&format!("failed to get location for uniform: {}", active.name));
+                    uniforms.insert(active.name, loc);
+                }
+            }
+
+            Self {
+                program,
+                uniforms: std::rc::Rc::new(uniforms),
+            }
+        }
+    }
+
+    pub fn new(ctx: &context::Context, vsrcstr: &str, fsrcstr: &str) -> Self {
+        let vsrc = format!("{}\n{}\n", COMMON_VERT, vsrcstr);
+        let fsrc = format!("{}\n{}\n", COMMON_FRAG, fsrcstr);
+        Self::new_nolib(ctx, &vsrc, &fsrc)
+    }
+
+    pub fn set_i32(&self, ctx: &context::Context, name: &str, val: i32) {
+        if let Some(loc) = self.uniforms.get(name) {
+            unsafe { ctx.gl.uniform_1_i32(Some(loc), val) }
+        }
+    }
+
+    pub fn set_i32_array(&self, ctx: &context::Context, name: &str, val: &[i32]) {
+        if let Some(loc) = self.uniforms.get(name) {
+            unsafe {
+                ctx.gl.uniform_1_i32_slice(Some(loc), val)
+            }
+        }
+    }
+
+    pub fn set_f32(&self, ctx: &context::Context, name: &str, val: f32) {
+        if let Some(loc) = self.uniforms.get(name) {
+            unsafe { ctx.gl.uniform_1_f32(Some(loc), val) }
+        }
+    }
+
+    pub fn set_vec3(&self, ctx: &context::Context, name: &str, val: &glam::Vec3) {
+        if let Some(loc) = self.uniforms.get(name) {
+            unsafe {
+                ctx.gl.uniform_3_f32(
+                    Some(loc),
+                    val.x,
+                    val.y,
+                    val.z,
+                );
+            }
+        }
+    }
+
+    pub fn set_vec4(&self, ctx: &context::Context, name: &str, val: &glam::Vec4) {
+        if let Some(loc) = self.uniforms.get(name) {
+            unsafe {
+                ctx.gl.uniform_4_f32(
+                    Some(loc),
+                    val.x,
+                    val.y,
+                    val.z,
+                    val.w,
+                );
+            }
+        }
+    }
+
+    pub fn set_mat4(&self, ctx: &context::Context, name: &str, val: &glam::Mat4) {
+        if let Some(loc) = self.uniforms.get(name) {
+            unsafe {
+                ctx.gl.uniform_matrix_4_f32_slice(
+                    Some(loc),
+                    false,
+                    &val.to_cols_array(),
+                );
+            }
+        }
+    }
+
+    pub fn set_position_3d(&self, ctx: &context::Context, position: &glam::Mat4) {
+        self.set_mat4(&ctx, "position", &position);
+        self.set_mat4(&ctx, "normal_matrix", &position.inverse().transpose());
+    }
+
+    pub fn set_position_2d(&self, ctx: &context::Context, pos: &glam::Vec2, dims: &glam::Vec2) {
+        let halfwidth = dims.x / 2.0;
+        let halfheight = dims.y / 2.0;
+        self.set_mat4(
+            &ctx, "position",
+            &glam::Mat4::from_scale_rotation_translation(
+                glam::Vec3::new(halfwidth, halfheight, 1.0),
+                glam::Quat::IDENTITY,
+                glam::Vec3::new(
+                    -context::RENDER_WIDTH / 2.0 + pos.x + halfwidth,
+                    context::RENDER_HEIGHT / 2.0 - pos.y - halfheight,
+                    0.0,
+                ),
+            )
+        );
+    }
+
+    pub fn bind(&self, ctx: &context::Context) {
+        unsafe {
+            ctx.gl.use_program(Some(self.program));
+        }
+    }
+}