split up painter into multiple files

src/renderer/painter_clipping.cpp

@@ -0,0 +1,42 @@
+#include <llmr/renderer/painter.hpp>
+#include <llmr/renderer/fill_bucket.hpp>
+#include <llmr/map/map.hpp>
+#include <llmr/util/clip_ids.hpp>
+
+using namespace llmr;
+
+void Painter::prepareClippingMask() {
+    gl::start_group("clipping masks");
+    useProgram(plainShader->program);
+    glDisable(GL_DEPTH_TEST);
+    depthMask(false);
+    glDepthRange(1.0f, 1.0f);
+
+    coveringPlainArray.bind(*plainShader, tileStencilBuffer, BUFFER_OFFSET(0));
+}
+
+void Painter::drawClippingMask(const mat4& matrix, const ClipID &clip) {
+    plainShader->setMatrix(matrix);
+
+    GLint id = clip.mask.to_ulong();
+    GLuint mask = clipMask[clip.length];
+    glStencilFunc(GL_ALWAYS, id, mask);
+    glStencilMask(0xFF);
+
+    Color background = map.getStyle().computed.background.color;
+    background[0] *= map.getStyle().computed.background.opacity;
+    background[1] *= map.getStyle().computed.background.opacity;
+    background[2] *= map.getStyle().computed.background.opacity;
+    background[3] *= map.getStyle().computed.background.opacity;
+
+    plainShader->setColor(background);
+
+    glDrawArrays(GL_TRIANGLES, 0, (GLsizei)tileStencilBuffer.index());
+}
+
+void Painter::finishClippingMask() {
+    glEnable(GL_DEPTH_TEST);
+    depthMask(true);
+    glStencilMask(0x0);
+    gl::end_group();
+}