Finish the OpenGL Renderer

.gitignore

@@ -1,4 +1,5 @@
 te
+ded
 SDL2
 *.exe
 *.obj

shaders/font.frag

@@ -14,13 +14,25 @@
 
 uniform sampler2D font;
 uniform float time;
+uniform vec2 resolution;
 
 in vec2 uv;
-in float glyph_ch;
-in vec4 glyph_color;
+flat in int glyph_ch;
+in vec4 glyph_fg_color;
+in vec4 glyph_bg_color;
+
+float map01(float x)
+{
+    return (x + 1) / 2.0;
+}
+
+vec3 hsl2rgb(vec3 c) {
+    vec3 rgb = clamp(abs(mod(c.x*6.0+vec3(0.0,4.0,2.0),6.0)-3.0)-1.0, 0.0, 1.0);
+    return c.z + c.y * (rgb-0.5)*(1.0-abs(2.0*c.z-1.0));
+}
 
 void main() {
-    int ch = int(glyph_ch);
+    int ch = glyph_ch;
     if (!(ASCII_DISPLAY_LOW <= ch && ch <= ASCII_DISPLAY_HIGH)) {
         ch = 63;
     }
@@ -32,5 +44,8 @@ void main() {
     vec2 size = vec2(FONT_CHAR_WIDTH_UV, -FONT_CHAR_HEIGHT_UV);
     vec2 t = pos + size * uv;
 
-    gl_FragColor = texture(font, t)* glyph_color;
+    vec4 tc = texture(font, t);
+    vec2 frag_uv = gl_FragCoord.xy / resolution;
+    vec4 rainbow = vec4(hsl2rgb(vec3((time + frag_uv.x + frag_uv.y), 0.5, 0.5)), 1.0);
+    gl_FragColor = glyph_bg_color * (1.0 - tc.x) + tc.x * glyph_fg_color * rainbow;
 }

shaders/font.vert

@@ -8,25 +8,33 @@
 #define FONT_CHAR_HEIGHT (FONT_HEIGHT / FONT_ROWS)
 
 uniform vec2 resolution;
+uniform vec2 scale;
+uniform float time;
+uniform vec2 camera;
 
-layout(location = 0) in vec2 pos;
-layout(location = 1) in float scale;
-layout(location = 2) in float ch;
-layout(location = 3) in vec4 color;
+layout(location = 0) in ivec2 tile;
+layout(location = 1) in int ch;
+layout(location = 2) in vec4 fg_color;
+layout(location = 3) in vec4 bg_color;
 
 out vec2 uv;
-out float glyph_ch;
-out vec4 glyph_color;
+flat out int glyph_ch;
+out vec4 glyph_fg_color;
+out vec4 glyph_bg_color;
 
 vec2 project_point(vec2 point)
 {
-    return 2.0 * point / resolution;
+    return 2.0 * (point - camera) / resolution;
 }
 
 void main() {
     uv = vec2(float(gl_VertexID & 1), float((gl_VertexID >> 1) & 1));
     vec2 char_size = vec2(float(FONT_CHAR_WIDTH), float(FONT_CHAR_HEIGHT));
+    vec2 pos = tile * char_size * scale;
+
     gl_Position = vec4(project_point(uv * char_size * scale + pos), 0.0, 1.0);
     glyph_ch = ch;
-    glyph_color = color;
+
+    glyph_fg_color = fg_color;
+    glyph_bg_color = bg_color;
 }

src/la.c

@@ -38,6 +38,48 @@ Vec2f vec2f_div(Vec2f a, Vec2f b)
     return vec2f(a.x / b.x, a.y / b.y);
 }
 
+//////////////////////////////
+
+Vec2i vec2i(int x, int y)
+{
+    return (Vec2i) {
+        .x = x,
+        .y = y,
+    };
+}
+
+Vec2i vec2is(int x)
+{
+    return vec2i(x, x);
+}
+
+Vec2i vec2i_add(Vec2i a, Vec2i b)
+{
+    return vec2i(a.x + b.x, a.y + b.y);
+}
+
+Vec2i vec2i_sub(Vec2i a, Vec2i b)
+{
+    return vec2i(a.x - b.x, a.y - b.y);
+}
+
+Vec2i vec2i_mul(Vec2i a, Vec2i b)
+{
+    return vec2i(a.x * b.x, a.y * b.y);
+}
+
+Vec2i vec2i_mul3(Vec2i a, Vec2i b, Vec2i c)
+{
+    return vec2i_mul(vec2i_mul(a, b), c);
+}
+
+Vec2i vec2i_div(Vec2i a, Vec2i b)
+{
+    return vec2i(a.x / b.x, a.y / b.y);
+}
+
+//////////////////////////////
+
 Vec4f vec4f(float x, float y, float z, float w)
 {
     return (Vec4f) {

src/la.h

@@ -13,6 +13,18 @@ Vec2f vec2f_mul(Vec2f a, Vec2f b);
 Vec2f vec2f_mul3(Vec2f a, Vec2f b, Vec2f c);
 Vec2f vec2f_div(Vec2f a, Vec2f b);
 
+typedef struct {
+    int x, y;
+} Vec2i;
+
+Vec2i vec2i(int x, int y);
+Vec2i vec2is(int x);
+Vec2i vec2i_add(Vec2i a, Vec2i b);
+Vec2i vec2i_sub(Vec2i a, Vec2i b);
+Vec2i vec2i_mul(Vec2i a, Vec2i b);
+Vec2i vec2i_mul3(Vec2i a, Vec2i b, Vec2i c);
+Vec2i vec2i_div(Vec2i a, Vec2i b);
+
 typedef struct {
     float x, y, z, w;
 } Vec4f;