WIP2: Text/texture rendering

src/Renderer.zig

@@ -8,18 +8,24 @@ const Self = @This();
 
 window: sdl.Window,
 context: sdl.gl.Context,
-//color_loc: u32,
 buffer: gl.Buffer,
-color: [4]f32,
+color: [4]f32 = .{ 0, 0, 0, 0 },
 
-test_counter: usize = 0,
+// There's a vbo for each shader program
+vbo: [nPrograms][max_objects]f32 = .{.{0.0} ** max_objects} ** nPrograms,
+vbo_index: [nPrograms]usize = .{0} ** nPrograms,
 
-vbo: [max_objects]f32 = .{0.0} ** max_objects,
+// The index of the program is the enum converted to int
-//colors: [max_objects][4]f32 = .{[4]f32{ 0.0, 0.0, 0.0, 1.0 }} ** max_objects,
+programs: [nPrograms]gl.Program = .{undefined} ** nPrograms,
-vbo_index: usize = 0,
 
 const max_objects: usize = 16384;
 
+const shaderProgram = enum {
+    color,
+    texture,
+};
+const nPrograms = std.meta.fields(shaderProgram).len;
+
 fn glGetProcAddress(p: []const u8, proc: [:0]const u8) ?*const anyopaque {
     _ = p;
     return sdl.c.SDL_GL_GetProcAddress(@ptrCast([*c]const u8, proc));
@@ -43,57 +49,30 @@ pub fn init() !Self {
         .{ .context = .opengl, .vis = .shown },
     );
 
+    const proc: []const u8 = undefined;
+    try gl.loadExtensions(proc, glGetProcAddress);
+
     const ctx = try sdl.gl.createContext(window);
     sdl.gl.setSwapInterval(.immediate) catch {
         std.debug.print("WARNING: Unable to configure the swap interval.\n", .{});
     };
 
-    const proc: []const u8 = undefined;
+    gl.enable(.blend);
-    try gl.loadExtensions(proc, glGetProcAddress);
+    gl.blendFunc(.src_alpha, .one_minus_src_alpha);
 
-    // Shader stuff
+    var buf = gl.Buffer.gen();
-    var mvp_loc: u32 = undefined;
+    buf.bind(.array_buffer);
-    const program = gl.Program.create();
-    {
-        const vs = gl.Shader.create(.vertex);
-        defer vs.delete();
-        const fs = gl.Shader.create(.fragment);
-        defer fs.delete();
 
-        vs.source(1, &.{@embedFile("shaders/vector.vs")});
+    var renderer = Self{ .window = window, .context = ctx, .buffer = buf };
-        fs.source(1, &.{@embedFile("shaders/fragment.fs")});
 
-        vs.compile();
+    // Load the shader programs according to the names in the enum
-        fs.compile();
+    inline for (std.meta.fields(shaderProgram)) |programEnum| {
-
+        renderer.programs[programEnum.value] = renderer.loadProgram(programEnum.name);
-        program.attach(vs);
-        defer program.detach(vs);
-        program.attach(fs);
-        defer program.detach(fs);
-
-        program.link();
-
-        mvp_loc = program.uniformLocation("mvp").?;
-    }
-    program.use();
-
-    // Get the matrix that converts coordinates to 1:1 on the screen from the OpenGL default
-    {
-        const wsize = window.getSize();
-        const xunit = @intToFloat(f32, wsize.width);
-        const yunit = @intToFloat(f32, wsize.height);
-
-        const ortho = m.Mat4.createOrthogonal(0.0, xunit, yunit, 0.0, 0.0, 100.0);
-
-        gl.uniformMatrix4fv(mvp_loc, false, &.{ortho.fields});
     }
 
     var vertex_array = gl.VertexArray.gen();
     vertex_array.bind();
 
-    const buf = gl.Buffer.gen();
-    buf.bind(.array_buffer);
-
     gl.vertexAttribPointer(0, 2, .float, false, @sizeOf(f32) * 8, @sizeOf(f32) * 0);
     gl.enableVertexAttribArray(0);
 
@@ -105,31 +84,74 @@ pub fn init() !Self {
 
     gl.clearColor(0.91, 0.85, 0.65, 1.00);
 
-    // TODO: See if there's a more optimal solution to this, maybe activating only when necessary
+    var text = Texture.fromText("testing123");
-    gl.enable(.blend);
+    _ = text;
-    gl.blendFunc(.src_alpha, .one_minus_src_alpha);
+    //text.deinit();
 
-    var text = Text.init("testing123");
+    return renderer;
-    text.deinit();
+}
 
-    return Self{ .window = window, .context = ctx, .buffer = buf, .color = .{ 0, 0, 0, 0 } };
+fn loadProgram(self: Self, comptime name: []const u8) gl.Program {
+    var program = gl.Program.create();
+
+    const vs = gl.Shader.create(.vertex);
+    defer vs.delete();
+    const fs = gl.Shader.create(.fragment);
+    defer fs.delete();
+
+    vs.source(1, &.{@embedFile("shaders/" ++ name ++ ".vert")});
+    fs.source(1, &.{@embedFile("shaders/" ++ name ++ ".frag")});
+
+    vs.compile();
+    fs.compile();
+
+    program.attach(vs);
+    defer program.detach(vs);
+    program.attach(fs);
+    defer program.detach(fs);
+
+    program.link();
+
+    // Get the matrix that converts coordinates to 1:1 on the screen from the OpenGL default
+    if (program.uniformLocation("mvp")) |mvpLocation| {
+        const wsize = self.window.getSize();
+        const xunit = @intToFloat(f32, wsize.width);
+        const yunit = @intToFloat(f32, wsize.height);
+
+        const ortho = m.Mat4.createOrthogonal(0.0, xunit, yunit, 0.0, 0.0, 100.0);
+
+        program.use();
+        gl.uniformMatrix4fv(mvpLocation, false, &.{ortho.fields});
+    }
+
+    return program;
 }
 
 pub fn render(self: *Self) void {
-    //std.debug.print("Number of rendered elements: {}\n", .{self.test_counter});
+    // Render with each of the defined shader programs
-    self.test_counter = 0;
+    for (self.programs) |_, program_i| {
+        self.programs[program_i].use();
 
-    self.buffer.data(f32, &self.vbo, .static_draw);
+        self.buffer.data(f32, &(self.vbo[program_i]), .static_draw);
+
+        switch (@intToEnum(shaderProgram, program_i)) {
+            .color => {
+                gl.drawArrays(.triangles, 0, self.vbo_index[program_i]);
+            },
+            .texture => {
+                gl.drawArrays(.triangles, 0, self.vbo_index[program_i]);
+            },
+        }
+
+        self.vbo_index[program_i] = 0;
+
+        // Clear the vbo, this really shouldn't be necessary as the index is set to zero,
+        // but otherwise it leads to bugs
+        self.vbo[program_i] = .{0.0} ** max_objects;
+    }
 
-    gl.drawArrays(.triangles, 0, self.vbo_index);
     sdl.gl.swapWindow(self.window);
     gl.clear(.{ .color = true });
-
-    self.vbo_index = 0;
-
-    // Clear the vbo, this really shouldn't be necessary as the index is set to zero,
-    // but otherwise it leads to bugs
-    self.vbo = .{0.0} ** max_objects;
 }
 
 pub fn deinit(self: *Self) void {
@@ -168,8 +190,7 @@ pub fn fillRectangle(self: *Self, x: i32, y: i32, w: i32, h: i32) void {
 }
 
 pub fn fillRectangleEx(self: *Self, x: i32, y: i32, w: i32, h: i32, skew_x: i32) void {
-    // TODO: Is this still necessary?
+    const program_i = @enumToInt(shaderProgram.texture);
-    self.test_counter += 1;
 
     var xf = @intToFloat(f32, x);
     var yf = @intToFloat(f32, y);
@@ -178,29 +199,35 @@ pub fn fillRectangleEx(self: *Self, x: i32, y: i32, w: i32, h: i32, skew_x: i32)
 
     const skew_x_offset = @intToFloat(f32, skew_x) * hf / 100;
 
-    const i = self.vbo_index;
+    const i = self.vbo_index[program_i];
     const vertex_data = [_]f32{
         xf + skew_x_offset, yf, // up-left
-        self.color[0], self.color[1], self.color[2], self.color[3],
+        self.color[0],      self.color[1],
-        0.0, 0.0,
+        self.color[2],      self.color[3],
+        0.0,                0.0,
         xf + wf + skew_x_offset, yf, // up-right
-        self.color[0], self.color[1], self.color[2], self.color[3],
+        self.color[0],           self.color[1],
-        1.0, 0.0,
+        self.color[2],           self.color[3],
+        1.0,                     0.0,
         xf - skew_x_offset, yf + hf, // down-left
-        self.color[0], self.color[1], self.color[2], self.color[3],
+        self.color[0],      self.color[1],
-        0.0, 1.0,
+        self.color[2],      self.color[3],
+        0.0,                1.0,
         xf + wf - skew_x_offset, yf + hf, // down-right
-        self.color[0], self.color[1], self.color[2], self.color[3],
+        self.color[0],           self.color[1],
-        1.0, 1.0,
+        self.color[2],           self.color[3],
+        1.0,                     1.0,
         xf + wf + skew_x_offset, yf, // up-right
-        self.color[0], self.color[1], self.color[2], self.color[3],
+        self.color[0],           self.color[1],
-        1.0, 0.0,
+        self.color[2],           self.color[3],
+        1.0,                     0.0,
         xf - skew_x_offset, yf + hf, // down-left
-        self.color[0], self.color[1], self.color[2], self.color[3],
+        self.color[0],      self.color[1],
-        0.0, 1.0,
+        self.color[2],      self.color[3],
+        0.0,                1.0,
     };
-    std.mem.copy(f32, self.vbo[i .. i + vertex_data.len], &vertex_data);
+    std.mem.copy(f32, self.vbo[program_i][i..], &vertex_data);
-    self.vbo_index += vertex_data.len;
+    self.vbo_index[program_i] += vertex_data.len;
 }
 
 fn renderRectangle(self: *Self, x: i32, y: i32, w: i32, h: i32) void {
@@ -216,46 +243,14 @@ pub fn getOutputSize(self: Self) OutputSize {
     };
 }
 
-const image = [_]u8{
+const Texture = struct {
-    // 1
-    0,0,0,
-    255,255,255,
-    0,0,0,
-    255,255,255,
-    // 2
-    255,255,255,
-    0,0,0,
-    255,255,255,
-    0,0,0,
-    // 1
-    0,0,0,
-    255,255,255,
-    0,0,0,
-    255,255,255,
-    // 2
-    255,255,255,
-    0,0,0,
-    255,255,255,
-    0,0,0,
-};
-
-const Text = struct {
     texture: gl.Texture,
 
-    pub fn init(text: [:0]const u8) Text {
+    pub fn init(data: [*]const u8, width: usize, height: usize) Texture {
         var tex = gl.genTexture();
         //defer gl.Texture.delete(tex);
         gl.bindTexture(tex, .@"2d");
 
-        var font = sdl.ttf.openFont("res/fonts/MarginaliaRegular-8XlZ.ttf", 200) catch unreachable;
-        //defer font.close();
-        var surface = font.renderTextBlended(text, sdl.Color.white) catch unreachable;
-        const width = @intCast(usize, surface.ptr.w);
-        const height = @intCast(usize, surface.ptr.h);
-        var newsurf = sdl.c.SDL_ConvertSurfaceFormat(surface.ptr, @enumToInt(sdl.PixelFormatEnum.argb8888), 0) orelse unreachable;
-        const data = @ptrCast([*]const u8, newsurf.pixels);
-        //defer surface.destroy();
-
         gl.textureImage2D(.@"2d", 0, .rgba, width, height, .rgba, .unsigned_byte, data);
 
         gl.texParameter(.@"2d", .wrap_s, .clamp_to_edge);
@@ -263,12 +258,27 @@ const Text = struct {
         gl.texParameter(.@"2d", .min_filter, .linear);
         gl.texParameter(.@"2d", .mag_filter, .linear);
 
-        return Text {
+        return Texture{
             .texture = tex,
         };
     }
 
-    pub fn deinit(self: *Text) void {
+    pub fn fromText(text: [:0]const u8) Texture {
-        _ = self;
+        var font = sdl.ttf.openFont("res/fonts/MarginaliaRegular-8XlZ.ttf", 200) catch unreachable;
+        defer font.close();
+
+        var surface = font.renderTextBlended(text, sdl.Color.white) catch unreachable;
+        defer surface.destroy();
+
+        const width = @intCast(usize, surface.ptr.w);
+        const height = @intCast(usize, surface.ptr.h);
+        var newsurf = sdl.c.SDL_ConvertSurfaceFormat(surface.ptr, @enumToInt(sdl.PixelFormatEnum.argb8888), 0) orelse unreachable;
+        const data = @ptrCast([*]const u8, newsurf.pixels);
+
+        return Texture.init(data, width, height);
+    }
+
+    pub fn deinit(self: *Texture) void {
+        gl.Texture.delete(self.texture);
     }
 };

src/shaders/color.frag

@@ -0,0 +1,7 @@
+#version 330 core
+
+in vec4 color;
+
+void main(){
+     gl_FragColor = color;
+}

src/shaders/color.vert

@@ -1,16 +1,12 @@
 #version 330 core
 
 layout (location = 0) in vec2 pos;
-layout (location = 1) in vec4 v_color;
+layout (location = 1) in vec4 vColor;
-layout (location = 2) in vec2 texcoord;
+out vec4 color;
-out vec2 Texcoord;
 
 uniform mat4 mvp;
 
-out vec4 color;
-
 void main() {
-     Texcoord = texcoord;
+     color = vColor;
-     color = v_color;
      gl_Position = mvp * vec4((pos + vec2(0.5, 0.5)), 0, 1);
 }

src/shaders/texture.frag

@@ -1,9 +1,9 @@
 #version 330 core
 
+in vec2 texcoord;
 in vec4 color;
-in vec2 Texcoord;
 uniform sampler2D tex;
 
 void main(){
-     gl_FragColor = texture(tex, Texcoord) * color;
+     gl_FragColor = texture(tex, texcoord) * color;
 }

src/shaders/texture.vert

@@ -0,0 +1,15 @@
+#version 330 core
+
+layout (location = 0) in vec2 pos;
+layout (location = 1) in vec4 vColor;
+out vec4 color;
+layout (location = 2) in vec2 vTexcoord;
+out vec2 texcoord;
+
+uniform mat4 mvp;
+
+void main() {
+     texcoord = vTexcoord;
+     color = vColor;
+     gl_Position = mvp * vec4((pos + vec2(0.5, 0.5)), 0, 1);
+}