render: scene: Apply base color texture and factor.

* chickadee/render/scene.scm (draw-primitive): Set base color texture
and send base color factor as uniform to shader.
* data/shaders/pbr/pbr-vert.glsl (texcoord_0): New input attribute.
(frag_tex): New output attribute.
* data/shaders/pbr/pbr-frag.glsl (frag_tex): New input attribute.
(base_color_factor, base_color_texture): New uniforms.

2 files changed, 9 insertions, 1 deletions

diff --git a/data/shaders/pbr/pbr-frag.glsl b/data/shaders/pbr/pbr-frag.glsl
index a4790b8..1552880 100644
--- a/data/shaders/pbr/pbr-frag.glsl
+++ b/data/shaders/pbr/pbr-frag.glsl
@@ -1,5 +1,10 @@
 #version 130
 
+in vec2 frag_tex;
+uniform vec3 base_color_factor;
+uniform sampler2D base_color_texture;
+
 void main (void) {
-  gl_FragColor = vec4(1.0, 0.0, 1.0, 1.0);
+  gl_FragColor = texture2D(base_color_texture, frag_tex) *
+    vec4(base_color_factor, 1.0);
 }
diff --git a/data/shaders/pbr/pbr-vert.glsl b/data/shaders/pbr/pbr-vert.glsl
index 938f475..b6fefef 100644
--- a/data/shaders/pbr/pbr-vert.glsl
+++ b/data/shaders/pbr/pbr-vert.glsl
@@ -1,8 +1,11 @@
 #version 130
 
 in vec3 position;
+in vec2 texcoord_0;
+out vec2 frag_tex;
 uniform mat4 mvp;
 
 void main(void) {
+  frag_tex = texcoord_0;
   gl_Position = mvp * vec4(position.xyz, 1.0);
 }