textured fills

fixes #15

src/renderer/shader-pattern.cpp

@@ -0,0 +1,27 @@
+#include <llmr/renderer/shader-pattern.hpp>
+#include <llmr/shader/shaders.hpp>
+#include <llmr/platform/gl.hpp>
+
+using namespace llmr;
+
+PatternShader::PatternShader()
+    : Shader(
+        shaders[PATTERN_SHADER].vertex,
+        shaders[PATTERN_SHADER].fragment
+    ) {
+    if (!valid) {
+        fprintf(stderr, "invalid pattern shader\n");
+        return;
+    }
+
+    a_pos = glGetAttribLocation(program, "a_pos");
+    attributes.emplace_front(a_pos);
+
+    u_matrix = glGetUniformLocation(program, "u_matrix");
+    u_color = glGetUniformLocation(program, "u_color");
+    u_offset = glGetUniformLocation(program, "u_offset");
+    u_pattern_size = glGetUniformLocation(program, "u_pattern_size");
+    u_pattern_tl = glGetUniformLocation(program, "u_pattern_tl");
+    u_pattern_br = glGetUniformLocation(program, "u_pattern_br");
+    u_mix = glGetUniformLocation(program, "u_mix");
+}